CN114802423B - Drive-by-wire turns to road feel analog system with mechanical redundancy - Google Patents
Drive-by-wire turns to road feel analog system with mechanical redundancy Download PDFInfo
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- CN114802423B CN114802423B CN202210475056.7A CN202210475056A CN114802423B CN 114802423 B CN114802423 B CN 114802423B CN 202210475056 A CN202210475056 A CN 202210475056A CN 114802423 B CN114802423 B CN 114802423B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
- B62D5/043—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by clutch means between driving element, e.g. motor, and driven element, e.g. steering column or steering gear
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/02—Power-assisted or power-driven steering mechanical, e.g. using a power-take-off mechanism for taking power from a rotating shaft of the vehicle and applying it to the steering gear
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B62—LAND VEHICLES FOR TRAVELLING OTHERWISE THAN ON RAILS
- B62D—MOTOR VEHICLES; TRAILERS
- B62D5/00—Power-assisted or power-driven steering
- B62D5/04—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear
- B62D5/0403—Power-assisted or power-driven steering electrical, e.g. using an electric servo-motor connected to, or forming part of, the steering gear characterised by constructional features, e.g. common housing for motor and gear box
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- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T90/00—Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
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Abstract
The invention discloses a drive-by-wire steering road feel simulation system with mechanical redundancy, which is characterized by comprising the following components: the road feel simulation motor adjusts the total torque output to the steering wheel according to the working condition when no fault exists, so that ideal road feel feedback is realized; the planetary gear mechanism realizes speed reduction and torque increase; the power coupling mechanism realizes power coupling between the gear ring and the sun gear through gear transmission; the electromagnetic clutch is switched to the backup system when the road feel simulation motor fails; the mechanical road feel simulation mechanism comprises a ball screw gear pair, a shock absorber, a torsion spring and the like, wherein the ball screw gear pair converts the rotary motion of a gear ring into the linear motion of a screw rod relative to the shock absorber, and the linear motion of the screw rod is used as a backup system to transmit the elastic force generated by the torsion spring and the damping force generated by the shock absorber to a steering wheel when a road feel simulation motor fails, so that the substitution simulation of the road feel is completed; therefore, when electronic elements such as the road sense simulation motor and the like are in faults, the electronic elements are switched to the backup system rapidly, and the reliability and the safety of the system are improved.
Description
Technical Field
The invention relates to the field of automobile steering-by-wire, in particular to a steering-by-wire road feel simulation mechanical redundancy device.
Background
Under the background of automobile innovation and four-in-one, the drive-by-wire of an automobile steering system is a necessary way for realizing intelligent driving. Compared with the traditional power-assisted steering system, the steering system cancels the mechanical connection between the steering wheel and the wheels, and realizes the steering and road feel feedback of the automobile by means of the sensor, the electric control unit and the actuator, thereby breaking through the restriction of the original mechanical connection, having wider space in design and having greater potential in the aspect of performance improvement. On one hand, the drive-by-wire steering system can freely design the transmission ratio, has light steering at low speed and sensitive steering at high speed, solves the contradiction between light steering and flexibility, on the other hand, the drive-by-wire steering technology and ABS, TCS, ESP and other technologies have the capacity of cooperative work, are favorable for the comprehensive control and development of chassis technology, have the capacity of active safety control, and have larger lifting space in the aspects of vehicle control stability, dynamic property, safety and the like.
Because of the potential of steer-by-wire technology in improving automobile steering and overall vehicle performance, various manufacturers have also begun to study steer-by-wire technology. The Infeinidi Q50 automobile manufactured by Nissan company is a first mass production type automobile carrying a steer-by-wire system, the steer-by-wire system of the automobile adopts a double steering executing motor to realize wheel steering, when one side motor fails, the other side motor can work as a backup successor, and when the two executing motors simultaneously fail, the motor can be converted into a mechanical steering system through engaging a clutch, and the motor still has the same function as the traditional steering automobile.
However, the steering system of the Infeinidi Q50 still has a mechanical intermediate shaft, and the steering system cannot be completely calculated as a steer-by-wire system. Unlike its design concept, the bosch advocates an electronic backup redundant steer-by-wire system, which completely eliminates the mechanical connection between the steering wheel and the steering actuator to account for true steer-by-wire. The steering-by-wire technology carried on Audi A3 vehicle for the director of the Bosch steering system is a set of failure operable system architecture, the steering-by-wire system adopts a full redundancy software and hardware scheme, the whole system architecture comprises a whole vehicle power supply, a communication, a signal, a steering execution motor, a processor and the like, and the full redundancy system scheme is adopted, namely, the whole steering-by-wire system is equivalent to that two sets of systems work in parallel in real time, and when one set fails, the other set can also continuously ensure that a steering instruction is executed. The system can be used for steering systems for L3 and above automatic driving.
While steer-by-wire systems have great advantages in improving overall vehicle performance, steer-by-wire systems that implement steering commands via control signals still present significant challenges in terms of stability, safety, and reliability as compared to the mechanical coupling schemes of conventional steer-by-wire systems. In terms of system constitution, the normal operation of the steer-by-wire system is not separated from the good operation states of various power supplies, sensors, communication systems, actuators, processors and the like, but the reliability of the steer-by-wire system is reduced due to the great complexity.
Therefore, the redundant system is indispensable to the normal operation of the steer-by-wire system, and the overall safety and reliability of the system can be further ensured. The steer-by-wire system may be classified into a road feel simulation system and a steering execution system. Through carrying out redundant design to the road feel simulation system, the reliability and the safety of the whole steer-by-wire system are further improved, and a series of safety problems generated when the road feel simulation system is switched to the mechanical steering system due to the fault of the road feel simulation system can be avoided.
Disclosure of Invention
The invention designs and develops a steering-by-wire road feel simulation system with mechanical redundancy aiming at various technical problems of the steering-by-wire system, which has two working modes of electronic road feel simulation and mechanical road feel simulation, can be switched to the mechanical road feel simulation mode when the electronic road feel simulation system fails, can meet the road feel feedback requirement of a driver at a low speed even though the road feel feedback moment fed back to the driver fluctuates when the electronic road feel simulation system is switched to the mechanical road feel simulation mode, namely realizes 'degradation' backup, still has road feel feedback under the dangerous working condition when the electronic road feel simulation system fails in the steering process, does not generate the dangerous condition of road feel loss, has high reliability, can effectively avoid the problem of reliability and safety reduction caused by excessive electronic elements of the road feel simulation system, simultaneously ensures that the road feel simulation system has a simple structure, is convenient to disassemble and assemble, is convenient to install and apply on an automobile, and is convenient for the system to realize further practical vehicle application.
The technical scheme of the invention is as follows:
a steer-by-wire road feel simulation system with mechanical redundancy, comprising:
the road feel simulation system comprises a road feel simulation system shell, a road feel simulation motor, a motor and a motor control unit, wherein the road feel simulation motor is fixed on the road feel simulation system shell and is used for generating feedback moment so as to enable a driver to obtain good road feel feedback;
a motor shaft coaxially connected with the road feel simulation motor;
the primary transmission driving gear is coaxially arranged on the motor shaft through key connection;
the motor reducer output shaft is coaxially provided with a primary driving driven gear which is connected with the primary driving driven gear by a key;
the sun gear shaft is selectively connected with the output shaft of the motor reducer through an electromagnetic clutch, so that the transmission and interruption of the motor power can be realized;
the electromagnetic clutch is used for controlling the selective connection and disconnection between the output shaft of the motor reducer and the sun gear shaft, realizing the power-off work under the common working condition that the motor works normally, realizing the axial connection between the output shaft of the motor reducer and the sun gear shaft and realizing the power transmission;
preferably, the electromagnetic clutch includes:
the electromagnetic clutch shell is connected with the road feel simulation system shell through screws;
An electromagnetic coil fixed in the electromagnetic clutch housing recess;
the armature is connected through a spline and is sleeved on the sun gear shaft in a sliding way, and the armature and the sun gear shaft work at the same rotating speed;
a torque adjusting ring which is connected with the sun gear shaft through threads;
one end of the spring is supported in the groove of the moment adjusting ring, the other end of the spring is fixedly connected to the armature, and the pressing force exerted on the armature by the spring can be adjusted by stirring the moment adjusting ring;
the spring positioning ring is connected and fixed on the sun gear through a wedge key so as to realize axial positioning of the first spring;
the friction plate is arranged on a flange of an output shaft of the motor speed reducer through a screw so as to increase the working torque of the electromagnetic clutch;
when the electromagnetic clutch is powered off, the spring presses the armature and makes the armature tightly abut against a flange of the motor reducer output shaft, so that the motor reducer output shaft and the sun gear shaft are axially connected, and the motor reducer output shaft and the sun gear shaft rotate at the same speed; when the electromagnetic clutch is electrified, the electromagnetic coil generates electromagnetic attraction force and attracts the armature to axially move, the armature is abutted against the spline tail end of the spline section of the sun gear shaft, the spring compresses the armature on the first friction plate, and the axial separation of the output shaft of the motor reducer and the sun gear shaft is realized, so that the sun gear shaft can freely rotate;
The planetary gear mechanism assembly, it is by sun gear axle, sun gear, planet wheel axle location retaining ring, holding ring, planet wheel bearing, planet carrier, ring gear etc. is constituteed, and it includes:
the sun gear is coaxially arranged on the sun gear shaft in a key connection manner;
the planet wheel is arranged on a planet wheel shaft through a planet wheel bearing and is meshed with the sun wheel;
the planetary wheel shaft is sleeved in the through hole of the planetary carrier, and axial positioning is realized by using a positioning retainer ring of the planetary wheel shaft;
a gear ring which is meshed with the planetary gear and is supported on the sun gear shaft;
the planet carrier is supported on the road sense simulation system shell, is provided with a through hole to be matched with the planet wheel shaft, and converts the circular motion of the planet wheel around the axis of the sun wheel shaft into the rotary motion of the planet carrier around the axis of the planet carrier;
preferably, the part of the planet carrier extending out of the road feel simulation system shell is provided with a spline, and the spline can be matched with a steering wheel to transmit the torque on the planet carrier to a driver through the steering wheel;
the power coupling mechanism comprises a primary coupling pinion, a primary coupling large gear, a power coupling shaft, a secondary coupling pinion and the like;
The primary coupling pinion is axially and fixedly connected with the sun gear shaft in a key connection mode;
the primary coupling large gear is axially and fixedly connected with the power coupling shaft in a key connection mode;
the secondary coupling pinion is axially and fixedly connected with the power coupling shaft in a key connection mode and is meshed with the gear ring in the planetary gear mechanism;
the power coupling shaft is used for realizing power coupling of the planetary gear mechanism, under the condition that the road feel simulation motor works normally, the electromagnetic clutch is in a power-off working state at the moment, part of power generated by the motor is transmitted to the sun gear through the primary transmission driving gear and the primary transmission driven gear, and the other part of power is transmitted to the gear ring through the primary transmission driving gear, the primary transmission driven gear, the primary coupling pinion, the primary coupling large gear, the primary coupling pinion and the secondary coupling pinion, so that power coupling of the planetary gear mechanism is realized, power is finally output outwards through the planet carrier, road feel moment feedback is realized, and road feel feedback is provided for a driver;
The mechanical road feel simulation mechanism comprises a nut, a screw rod, a damper mounting flange, a torsion spring and the like, wherein an internal circulation ball screw nut pair formed by the screw rod and the nut converts the rotary motion of the gear ring into the linear motion of the screw rod, and the motion of the screw rod in the damper generates damping force required by road feel simulation; the rotary motion of the gear ring enables the torsion spring to elastically deform and generate elastic force required by road feel simulation;
the nut is made into a whole with the gear and meshed with the gear ring in the planetary gear structure for transmission;
the screw rod and the nut with the ball roller path inside form an internal circulation ball screw nut pair together so as to convert the rotary motion of the gear ring into the linear motion of the screw rod;
the lead screw is a piston rod of the shock absorber during working, and when the lead screw and the shock absorber perform relative movement, the shock absorber generates corresponding damping force to block the relative movement between the lead screw and the shock absorber;
preferably, the vibration damper is a bidirectional cylinder type vibration damper, when the lead screw is far away from the middle position of the vibration damper, namely a steering process, and when the lead screw is close to the middle position of the vibration damper, namely a steering return process, the vibration damper can generate corresponding damping force in the steering process and the steering return process, namely the bidirectional cylinder type vibration damper;
Preferably, the damping of the shock absorber is adjustable, and the damping force is different in the steering process and the steering return process, and the damping of the shock absorber is larger in the steering process so as to ensure enough road feel feedback moment; in the steering centering process, the damping of the shock absorber should be small to ensure that the steering wheel can be quickly centered under the action of the elastic force of the torsion spring in the steering centering process, and the shock absorber should be ensured to have certain damping to prevent the shimmy phenomenon from occurring when the steering wheel is centered to the middle position;
preferably, the limit position to which the lead screw can move in the shock absorber corresponds to the limit position to which the steering wheel is unidirectionally rotated, and in general, the physical limit of the steering wheel is realized, and the steering wheel is prevented from further steering so as to be matched with the steering movement of the traditional automobile;
one end of the torsion spring is fixedly connected with the road feel simulation system shell, and the other end of the torsion spring is fixedly connected with the gear ring, so that the torsion spring is deformed when the gear ring rotates, and the elastic force required by road feel simulation is generated;
preferably, the elastic force generated by the torsion spring after deformation can overcome the damping force of the shock absorber and simultaneously automatically return the steering wheel;
Preferably, the planetary gear mechanism can complete switching of two working modes under the control of the electromagnetic clutch;
preferably, when the whole road feel simulation electronic device comprises a sensor, a power supply, a wire, an electronic control unit, a communication system, a road feel simulation motor and the like which are required by road feel simulation and work normally without faults, the electromagnetic clutch is in a power-off state, and the output shaft of the motor reducer is axially connected with the sun gear shaft to realize constant-speed operation of the motor reducer and the sun gear shaft, so that the whole road feel simulation system is in an electronic road feel simulation mode;
preferably, in the electronic road feel simulation mode, the vibration damper and the torsion spring in the mechanical road feel simulation mechanism are still in a working state, so that the road feel torque transmitted to the driver at the moment is the road feel torque generated by the mechanical road feel simulation mechanism and the road feel simulation motor together, and the total road feel torque is ideal road feel feedback for the driver under the current working condition under the control of the road feel simulation motor, so that the driver can be ensured to obtain ideal driving feedback; in addition, in the electronic road feel simulation mode, the vibration damper and the torsion spring in the mechanical road feel simulation mechanism are still in a working state, so that under the condition that electronic elements such as a road feel simulation motor are invalid, the moment generated by the mechanical road feel simulation mechanism can act on the steering wheel immediately, the road feel feedback moment fluctuates, the condition that the road feel is lost is avoided, and the safety and the stability of the system are still reliably ensured;
In an electronic road feel simulation mode, the road feel simulation motor and the mechanical road feel simulation mechanism jointly provide road feel feedback moment required in the steering process, the road feel simulation motor is controlled, and road feel feedback fed back to a driver is regulated according to the current working condition, so that the total road feel feedback moment meets ideal road feel feedback of the driver under the current working condition; at the moment, part of the power generated by the road feel simulation motor is transmitted to the sun gear through the motor shaft, the motor reducer output shaft and the sun gear shaft, and the other part of the power is transmitted to the gear ring through the motor shaft, the motor reducer output shaft, the sun gear shaft and the power coupling shaft, so that the power coupling of the planetary gear mechanism is realized, and the power generated by the road feel simulation motor is output to the steering wheel through the planet carrier, so that the road feel simulation is realized;
preferably, the first-stage coupling pinion and the first-stage coupling large gear form a transmission ratio of:
wherein z is 2 Z, the number of teeth of the primary coupling pinion 1 The number of teeth of the primary coupling large gear is the number of teeth of the primary coupling large gear;
preferably, the characteristic parameter of the planetary gear mechanismThe number is alpha, namely the gear ratio of the gear ring and the sun gear, 
Wherein z is 3 For the number of teeth of the gear ring, z 4 The number of teeth of the sun gear is the number of teeth of the sun gear;
preferably, the gear ratio formed by the secondary coupling pinion and the gear ring is:
wherein z is 5 The number of teeth for the secondary coupling pinion;
under the condition of an electronic road feel simulation working mode, the rotating speeds of the gear ring and the sun gear meet the relation:
n 4 ＝n 3 *i 1 *i 2 wherein n is 4 For the rotation speed of the sun gear, n 3 Is the rotational speed of the ring gear;
the negative sign in the above formula indicates that in this operating mode, the rotational speed of the sun gear is opposite to the rotational speed of the ring gear;
the rotational speed n of the planet carrier at this time 0 And the rotational speed n of the sun gear 4 The relation is satisfied:
the transmission ratio of the planetary gear mechanism is:
preferably, the gear pair formed by the primary transmission driving gear and the primary transmission driven gear has the transmission ratio of:
preferably, when the road feel simulation system is in the electronic road feel simulation working mode, the transmission ratio of the whole system is as follows:
i 0 ＝i 3 *i 4 namely, a larger transmission ratio transmission is formed by the planetary gear mechanism and the power coupling mechanism, so that the model selection matching of the road feel simulation motor is facilitated;
Preferably, in the case that any electronic component such as a sensor, a power supply, a wire, an electronic control unit, a communication system and the road feel simulation motor required by the whole road feel simulation electronic device is failed, the electromagnetic clutch is electrified, so that the electromagnetic attraction force generated by the electromagnetic clutch axially moves the armature, the armature is changed from a state of being pressed by the flange of the output shaft of the motor reducer to a state of being abutted against the spline end of the sun gear shaft, and the axial connection between the output shaft of the motor reducer and the sun gear shaft is disconnected, so that the sun gear shaft can freely rotate relative to the output shaft of the motor reducer, and the whole road feel simulation system is in a mechanical road feel simulation mode;
in the mechanical road feel simulation mode, the input of the driver is equivalent to the power source of the whole road feel simulation system, and the feedback moment acted on the steering wheel at the moment is only provided by the mechanical road feel simulation mechanism, so that the road feel feedback obtained by the driver fluctuates relative to the electronic road feel feedback mode, the road feel is not lost, and the driver still has the driving feel of controlling the automobile; in the steering process, the power input by a driver is input to the gear ring through the planet carrier to enable the gear ring to rotate, on one hand, the elasticity generated when the torsion spring arranged on the gear ring rotates is needed to be overcome, on the other hand, as the outer end of the nut in the damping simulation mechanism is provided with a gear and is meshed with the gear ring, when the rotational motion of the gear ring is input into the ball screw nut pair, the screw rod relatively moves relative to the shock absorber, namely, the shock absorber also generates corresponding damping force to act on the gear ring at the moment, and therefore, the power input by the driver also needs to overcome the damping force in the steering process to realize degraded road feel simulation;
Preferably, when the road feel simulation system works in a mechanical road feel simulation working mode, a driver does not need to input extra steering force in the steering return process; when the steering wheel rotates to a certain angle, the rotary motion of the gear ring forces the torsion spring to generate corresponding elastic deformation, so the torsion spring has certain elastic potential energy, so the elastic potential energy of the torsion spring is released in the steering return process, and the generated elastic force forces the gear ring to return to the initial position, namely the steering wheel connected with the planet carrier also returns to the initial position, and even if the steering wheel is automatically returned to the normal position;
preferably, when the elastic potential energy accumulated in the torsion spring is released, the elastic force acting on the gear ring enables the gear ring to return, and the lead screw relatively moves relative to the shock absorber, so that the part of elastic force overcomes the damping force and the friction force in the whole transmission process to lead the steering wheel to return, and the phenomenon that the elastic force generated by the torsion spring is only used as power for leading the steering wheel to return and is shimmy at the middle position of the steering wheel is avoided, and the steering wheel is returned and stabilized;
Preferably, when the electromagnetic clutch is energized to operate the road feel simulation system in the mechanical road feel simulation mode, each component of the planetary gear mechanism satisfies:
n 4 ＝n 3 *i 1 *i 2 wherein n is 4 For the rotation speed of the sun gear, n 3 Is the rotational speed of the ring gear;
the rotational speed n of the ring gear at this time 3 And the planet carrier n 0 The rotational speed of (2) satisfies the relation:
n 3 *i 1 *i 2 +α*n 3 ＝(1+α)*n 0 ；
in the mechanical road feel simulation mode, the input part of the planetary gear mechanism is the planet carrier, and the output part of the planetary gear mechanism is the gear ring, so that the transmission ratio of the planetary gear mechanism is as follows:
preferably, the gear pair transmission ratio i formed by reasonably designing the primary coupling pinion and the primary coupling large gear 1 And the gear ratio i of the gear pair formed by the secondary coupling pinion and the gear ring 2 Because the output element and the output element of the system are changed in the two working modes, the planetary gear mechanism can realize the speed reduction and torque increase of the input moment in the electronic road feel simulation working mode and the mechanical road feel simulation working mode, namely the input moment is ensured to be i 0 |>1、
Preferably, the elastic characteristic of the torsion spring and the damping characteristic of the shock absorber in the mechanical road feel simulation mechanism should be designed according to ideal road feel feedback of a driver under low speed, namely, road feel simulation feedback moment felt by the driver under low speed driving working conditions is provided by the mechanical road feel simulation mechanism for the most part; under the low-speed driving working condition, the lateral acceleration of the automobile is not greatly changed relative to the steering wheel rotation angle, so that factors mainly influencing the ideal road feel feedback moment are mainly steering wheel rotation angle and the change rate of the steering wheel rotation angle, and the moment generated by the mechanical road feel simulation mechanism is a function of the steering wheel rotation angle and the change rate of the steering wheel rotation angle as independent variables, so that the mechanical road feel simulation mechanism can more ideally meet the ideal road feel feedback of a driver under the low-speed driving working condition, namely the design concept is reasonable, and meanwhile, the low-custom road feel requirement of the driver under the low-speed driving working condition is met; under the low-speed driving working condition, the road feel simulation motor still generates feedback moment, but the magnitude of the road feel simulation motor is very small relative to the moment generated by the mechanical road feel simulation mechanism, and only plays a role in adjusting the total road feel feedback fed back to a driver according to the current working condition, so that the road feel simulation system can provide ideal road feel feedback for the driver;
Preferably, the elastic characteristic of the torsion spring and the damping characteristic of the shock absorber in the mechanical road feel simulation mechanism are designed according to ideal road feel feedback of a driver at a low speed, and the driver can choose to reduce the speed of the vehicle to avoid potential danger after sensing the faults of the road feel simulation motor and related electronic elements in the road feel simulation system, so that the road feel feedback requirement provided by the mechanical road feel simulation mechanism serving as a backup system can just meet the road feel feedback requirement expected by the current driver;
preferably, during high-speed running, the road feel simulation motor and the mechanical road feel simulation mechanism jointly act to realize ideal road feel simulation, and at the moment, the feedback moment provided by the road feel simulation motor is much larger than the feedback moment generated at low speed so as to provide larger moment feedback effect for a driver, so that the requirement of high-speed driving stability of the driver is met;
preferably, after the road feel simulation system performs the above design, after the road feel simulation motor and related electronic component devices fail, that is, when the electronic road feel simulation mode is switched to the mechanical road feel simulation mode, the influence of the inconsistency of the mechanical road feel simulation and the ideal road feel simulation on the experience of a driver is minimal, so that the driver can obtain relatively real road feel feedback during low-speed driving, and the deterioration of driving safety and road feel experience influenced by misoperation is reduced;
The invention has the beneficial effects that:
1. the invention designs a steering-by-wire road feel simulation system with mechanical redundancy, which utilizes a series of electromechanical execution systems to ensure that the road feel simulation system can work normally on the whole road feel simulation electronic device, wherein the road feel simulation electronic device comprises sensors, a power supply, wires, an electronic control unit, a communication system, a road feel simulation motor and the like which are required by road feel simulation, and when the road feel simulation motor does not work faults, road feel feedback obtained by a driver is regulated by the motor according to driving conditions, namely an electronic road feel simulation mode is provided, so that the driver obtains ideal road feel feedback; when the road feel simulation electronic device fails and cannot work normally, the drive-by-wire steering road feel simulation system can work in a mechanical road feel simulation mode through the electromagnetic clutch, and road feel simulation is realized by using mechanical devices such as a torsion spring, a shock absorber and the like. According to the invention, under the condition of electronic component faults, fault-tolerant control can be realized through controlling the electromagnetic clutch, so that the road feel simulation system can continuously realize road feel simulation by utilizing a series of mechanical devices, and the road feel simulation system has the advantages of functional backup, higher fault-tolerant performance, higher functional safety level and improved stability and reliability.
2. The invention realizes fault-tolerant control of the road feel simulation system by using a mechanical redundancy mode, has simple control method, and can realize the conversion of the road feel simulation system from an electronic road feel simulation working mode to a mechanical road feel simulation working mode by controlling the electromagnetic clutch only; compared with other electronic redundant road feel simulation systems, the invention can quickly respond and switch to a mechanical road feel simulation working mode when a series of faults occur in corresponding electronic devices, and can immediately switch to the mechanical road feel simulation mode and provide road feel feedback under the dangerous condition that electronic components are in fault in the steering process, although the road feel feedback moment fluctuates, a driver can still obtain necessary road feel feedback moment and meet the ideal road feel feedback requirement under the low speed, and the fluctuation of the road feel feedback moment is reduced to the minimum by reasonably designing elements in the mechanical road feel simulation mechanism, so that the driver keeps the control of the driving automobile feel, namely the problem of no road feel loss, and the reliability is higher, thereby being beneficial to the application of the road feel simulation system on a real vehicle.
3. Compared with other road sense simulation systems adopting electronic redundancy such as double-motor redundancy and the like, the road sense simulation system has the advantages that the mechanical device with higher reliability and lower cost is utilized, so that functional backup can be realized, the number of electronic devices is reduced, the complexity of the system is reduced, the failure rate is lower, the safety level is higher, the road sense simulation system is ensured to have higher stability under the condition of low cost, and the application of the road sense simulation system in the industrial field is further promoted.
4. According to the invention, the planetary gear mechanism is designed to realize power coupling, and the transmission ratio of the gear pair for realizing power coupling is designed, so that the planetary gear mechanism can amplify the torque input by a power source in both an electronic road feel simulation working mode and a mechanical road feel simulation working mode, the design flexibility is higher, the matching selection of a road feel simulation motor is facilitated, the matching connection with a steering wheel is facilitated, the road feel simulation system is optimally designed, the integration degree is higher, the whole road feel simulation system is simplified, and meanwhile, the split type shell design is adopted, so that the whole road feel simulation system is convenient to disassemble, assemble and maintain.
Drawings
Fig. 1 is a cross-sectional view of a steering-by-wire road feel simulation system with mechanical redundancy according to the present invention.
Fig. 2 is a diagram of an arrangement of a steering-by-wire road feel simulation system with mechanical redundancy according to the present invention.
FIG. 3 is a cross-sectional view of a shock absorber according to the present invention;
FIG. 4 is a schematic diagram of the drive motion of the steer-by-wire road feel simulation system with mechanical redundancy of the present invention operating in an electronic road feel simulation mode when the associated electronics components are operating properly;
FIG. 5 is a schematic diagram of the drive motion of the steer-by-wire road feel simulation system with mechanical redundancy of the present invention operating with a mechanical backup device in a mechanical road feel simulation mode when a related electronic device component fails;
Detailed Description
The present invention is described in further detail below with reference to the drawings, so that those skilled in the art can implement the present invention by referring to the description;
fig. 2 is a schematic diagram of a steer-by-wire road feel simulation system with mechanical redundancy according to the present invention. The steering-by-wire road feel simulation system with mechanical redundancy mainly comprises a road feel simulation motor 110, a mode switching mechanism, a power coupling mechanism, a planetary gear mechanism, a mechanical road feel simulation mechanism, a road feel simulation system shell and the like. The road-feel simulation system housing 620 is mounted on a support 840 via a support 830, preferably a steering gear of a conventional steering vehicle is mounted on a steering gear support, on which the system device can be mounted for the steer-by-wire road-feel simulation system with mechanical redundancy according to the invention, i.e. the steering gear support on the conventional steering vehicle can serve as the support 830 for the system device. Preferably, the planet carrier 550 in the planetary gear mechanism in the steer-by-wire road feel simulation system with mechanical redundancy is used as a power output element and is connected with the steering column pipe 820 through a spline, so that the road feel feedback moment output by the steer-by-wire road feel simulation system acts on the steering wheel 810 connected with the steering column pipe 820 to realize road feel feedback.
FIG. 1 is a schematic cross-sectional view of a steer-by-wire feel simulation system with mechanical redundancy according to the present invention; the steering-by-wire road feel simulation system with mechanical redundancy mainly comprises a road feel simulation motor 110, a mode switching mechanism, a power coupling mechanism, a planetary gear mechanism, a mechanical road feel simulation mechanism, a road feel simulation system shell and the like. The road feel simulation system shell is of a split design and consists of a first shell 610, a second shell 620, a third shell 630 and an end cover 640, wherein the shells are connected through bolts uniformly distributed in the circumferential direction. The first housing 610 mainly accommodates a mode switching mechanism, a road feel simulation motor 110, and a damper 720 in a mechanical road feel simulation mechanism; the cavity of the second housing 620 mainly accommodates a ball screw gear pair in the power coupling mechanism and the mechanical road feel simulation mechanism; the third housing 630 has a cavity that mainly accommodates the torsion springs 710 in the planetary gear mechanism and the mechanical feel simulation mechanism. Wherein the road feel simulation motor 110 is mounted on the outer housing 610 of the road feel simulation system by the mounting flange 120 through the screws 121, and the axes of the road feel simulation motor and the mounting flange are parallel to each other. The primary transmission driving gear 140 is fixedly installed on the motor shaft 130 in a connection manner, and is engaged with the primary transmission driven gear 220 installed on the motor reducer output shaft 210 through a key connection to form an engaged gear pair, so that the power generated by the road feel simulation motor 110 is reduced in speed and increased in torque and transmitted to the motor reducer output shaft 210.
The road feel simulation motor 110 is used for adjusting the road feel feedback moment fed back to the driver according to the working condition so as to enable the driver to obtain ideal steering feel. The control of the road feel feedback moment generated by the road feel simulation motor 110 should meet the requirements of accurate and adjustable torque, high response speed and stable torque change process as much as possible, so as to prevent the problems of steering wheel drivers and the like. Therefore, the road feel simulation motor 110 should have the advantages of bidirectional rotation, accurate and adjustable output torque, stable operation, high execution speed, high reliability and the like, and should have the characteristics of compact structure, convenient arrangement and the like in structure. Preferably a direct current servo motor.
As shown in fig. 1, the mode switching structure according to the present invention mainly includes a motor reducer output shaft 210, an electromagnetic clutch 310, and a sun gear shaft 570. Preferably, the electromagnetic clutch 310 is used to control the motor reducer output shaft 210 and the sun gear shaft to rotate at the same speed or freely, so as to determine whether the torque output by the road feel simulation motor 110 participates in the generation of the road feel feedback torque.
As shown in fig. 1, the electromagnetic clutch 310 mainly includes an electromagnetic clutch housing 310, a torque adjusting ring 380, a spring support base 370, a spring positioning ring 360, a spring 330, a friction plate 321, an armature 320, a yoke 391, and a coil 390. As shown in fig. 1, the electromagnetic clutch housing 310 is connected to the second housing 620 of the road feel simulation system by 6 screws uniformly distributed in the circumferential direction. The yoke 391 and coil 390 of the electromagnetic clutch are fixed to the electromagnetic clutch housing 310.
Preferably, the torque adjusting ring 380 is axially fixed to the sun gear shaft 570 by a threaded connection, i.e. the sun gear shaft 570 has external threads corresponding to the connection portion, so as to allow the torque adjusting ring 380 to be rotated thereon, thereby adjusting the pre-tightening force of the spring 330. Preferably, the spring retainer ring 360 is secured to the sun gear shaft 570 via a keyed connection that cooperates with the electromagnetic clutch housing 310 to circumferentially retain the spring 330. Preferably, the spring 330 rests on a spring support base 370 mounted to a corresponding recessed portion of the torque adjustment ring 380 at one end and rests on the armature 320 at the other end. As shown in fig. 1, sun gear shaft 570 is splined to a shaft section within electromagnetic clutch 310 so as to be axially coupled to armature 320 and so that armature 320 can slide axially over the shaft section. Preferably, the friction plate 321 is fixed to the flange of the motor reducer output shaft 210 by connecting screws uniformly arranged in the circumferential direction.
Preferably, as shown in fig. 1, when the electromagnetic clutch 310 is powered off, the spring 330 presses the armature 320 against the friction plate 321 fixed to the flange of the motor reducer output shaft 210 by its own spring force, so that the motor reducer output shaft 210 and the sun gear shaft 570 are connected together, and both rotate synchronously at the same rotation speed. When the electromagnetic clutch 310 is in the energized state, the coil 390 generates a corresponding electromagnetic attraction force, thereby attracting the armature 320 to slide axially along the spline section of the sun gear shaft 570 and abut against the tail end of the spline section of the sun gear shaft 570 under the action of electromagnetic force, thereby breaking the fixed connection relationship between the motor reducer output shaft 210 and the sun gear shaft 570, and enabling the sun gear shaft 570 to rotate freely relative to the motor reducer output shaft 210.
Preferably, by pulling the first torque adjusting ring 545 which is fixed on the first half shaft in a threaded connection, the initial compression amount of the first spring 541 can be changed, so that the pretightening torque of the electromagnetic clutch 310 can be changed, the problem that the working torque of the electromagnetic clutch is reduced due to gradual abrasion of the friction plate in the running process of the road feel simulation system can be solved, and the whole road feel simulation system can work more reliably.
As shown in fig. 1, the power coupling mechanism according to the present invention is composed of a primary coupling pinion 430, a primary coupling large gear 420, a power coupling shaft 410, and a secondary coupling pinion. Wherein, the primary coupling pinion 430 is mounted on the sun gear shaft 570 by means of a key connection, and the primary coupling large gear 420 is mounted on the power coupling shaft 410 by means of a key connection and is engaged with the primary coupling pinion, so that the power from the road feel simulation motor 110 is transferred from the sun gear shaft 570 to the power coupling shaft 410. The secondary coupling pinion is also mounted on the power coupling shaft 410 through a key connection and is meshed with the gear ring 530 in the planetary gear mechanism, so that power is further transmitted from the power coupling shaft 410 to the gear ring 530, and the sun gear 510 in the planetary gear mechanism is also mounted on the sun gear shaft 570 through a key connection, so that the planetary gear 510 and the gear ring 530 in the planetary gear mechanism rotate together at a fixed proportion of rotating speed, namely power coupling of the planetary gear mechanism is realized, power from the road feel simulation motor 110 is input to the planetary gear 510 and the gear ring 530, is output from the planet carrier 550, and acts on the steering wheel together with torque generated by the mechanical road feel simulation mechanism, so that road feel feedback is realized.
As shown in fig. 1, the planetary gear mechanism according to the present invention includes a sun gear shaft 570, a sun gear 510, a planetary gear shaft 570, a planetary gear shaft 560, a planetary gear 540, a ring gear 530, a positioning ring 561, an adjustment washer 562, a planetary gear bearing 565, a hole positioning ring 564, a shaft positioning ring 563, and a carrier 550. Wherein sun gear 510 is keyed to and secured to sun gear shaft 570, and carrier 550 and its bearings are mounted together in a socket of end cap 640 of the road feel simulation system. Wherein the shaft end flange of the planet carrier 550 is provided with a through hole, the planet axle 560 is arranged in the through hole, the planet axle 560 is axially positioned by a positioning ring 561 and a positioning ring 563 for the shaft, and the tightness of the connection between the planet axle 560 and the planet carrier 550 is adjusted by an adjusting washer 562. Wherein the planet 540 is meshed with the sun 510 and the ring 530 simultaneously, and the planet and its bearings are mounted on the planet axle 560 and positioned by the positioning ring 564 through the holes. Wherein the ring gear 530 is bearing mounted on the sun gear shaft 570 and intermeshes with the planet gears 540.
As shown in fig. 1, the mechanical road feel simulation mechanism of the present invention is composed of a torsion spring 710, a nut 730, a screw 740, a damper 720, and the like. Torsion spring 710 is mounted at one end in end cap 640 and at one end to ring gear 530 and is circumferentially and centrally located by end cap 640. The outer end of the nut 730 is provided with a gear, and is meshed with a gear ring 530 in the planetary gear mechanism, and the nut 730 and the screw 740 form an internal circulation ball screw nut pair together, so that the input rotary motion is converted into linear motion. The nut 730 is mounted on the second housing 620 of the road feel simulation system through one end of a bearing and the other end is mounted on the sun gear shaft 570, so that the nut 730 can only perform a rotational motion during operation, and thus the rotational motion of the nut 730 is converted into a linear motion of the screw 740. The damper 720 is screw-mounted to the first housing 610 of the road feel simulation system through the mounting flange 750. The lead screw 740 is integrally formed with a piston rod in the damper 720, so that the lead screw 740 moves the piston of the damper 720 relative to the damper cylinder during linear motion, and thus the damper generates a damping force.
As shown in fig. 3, a cross-sectional view of the structure of the shock absorber according to the present invention is shown; the shock absorber 720 includes a piston rod 740, a seal air chamber 721, a floating piston 722, an O-ring 723, a compression valve 724, a cylinder 725, a piston 727, and an extension valve 728. The working piston 727 is provided with a compression valve 724 and an extension valve 728 which change the cross-sectional area of a channel according to the movement speed, and the two valves are composed of a group of spring steel sheets which have the same thickness and different diameters and are arranged from large to small. As shown in fig. 1, the screw rod 740 in the mechanical path feel simulation mechanism is integrally formed with the piston rod 740 in the shock absorber, when the screw rod 740 makes linear motion, namely, the working piston 727 of the shock absorber 720 makes reciprocating motion in oil, so that oil pressure difference is generated between the upper cavity and the lower cavity of the working piston 727, and the pressure oil pushes the compression valve 724 or the extension valve 728 to flow back and forth, and because the valve generates larger damping to the pressure oil, vibration energy is consumed, and vibration is attenuated.
The drive-by-wire steering road feel simulation system with mechanical redundancy can be used for feeding back the moment generated by the road feel simulation motor and the moment generated by the mechanical road feel simulation mechanism to a driver together under the condition that related electronic device elements work normally, namely in an electronic road feel simulation mode, and the road feel simulation motor adjusts the total moment fed back to the driver according to driving conditions to form ideal road feel feedback required by the driver; the drive-by-wire steering road feel simulation system can be rapidly switched to a mechanical road feel simulation mode under the condition that related electronic device elements are in failure, and particularly, a certain road feel feedback can be provided by using a mechanical device under the dangerous condition that the elements are in failure in the steering process, although the moment transmitted to a driver at the moment is only generated by a mechanical road feel simulation mechanism, namely, the road feel fed back to the driver fluctuates, and the ideal road feel feedback requirement of the driver under the low-speed condition can be met, the situation that the road feel is lost in the whole process is avoided, and therefore accidents such as steering misoperation caused by the loss of the necessary road feel feedback of the driver can be avoided, and the reliability and the safety of the road feel simulation system can be effectively improved.
In the electronic road feel simulation mode, the electromagnetic clutch 310 is in a power-off state, at the moment, the spring force of the clutch spring 330 presses the armature 320 on the flange end of the motor reducer output shaft 210, the armature 320 is connected with the sun gear shaft 570 through a spline, at the moment, the motor reducer output shaft 210 and the sun gear shaft 570 are axially connected together to realize coaxial rotation, namely, the power of the motor reducer output shaft 210 is transmitted to the sun gear shaft 570. In this mode of operation, for the planetary gear mechanism, primary coupling pinion 430, which is keyed to sun gear shaft 570, intermeshes with primary coupling bull gear, which is keyed to power coupling shaft 410, and transfers power on sun gear shaft 570 to power coupling shaft 410. The secondary coupling pinion 440 fixedly installed on the power coupling shaft 410 is meshed with the gear ring 530 in the planetary gear mechanism through a key connection, and power from the sun gear shaft 510 is transmitted to the gear ring 530 in the planetary gear mechanism, namely, at the moment, the sun gear 510 and the gear ring 530 in the planetary gear mechanism, which are installed on the sun gear shaft 570 through the key connection, rotate at a fixed proportion, namely, a part of the power from the road feel simulation motor 110 is transmitted to the sun gear 510 in the planetary gear train, and the other part of the power is transmitted to the gear ring 530 in the planetary gear train through the power coupling mechanism, namely, power coupling is realized, and the power is output from the planet carrier 550, and the planet carrier 550 is mechanically connected with the steering wheel, so that the moment generated by the road feel simulation motor 110 and the mechanical road feel simulation mechanism acts on the steering wheel together, and the total feedback moment transmitted to a driver through the road feel simulation motor 110 is adjusted according to working conditions, the automatic return force in the steering wheel steering process and the limit moment when the steering wheel rotates to a limit position are used as resistance in the steering wheel steering process, the limit function of the traditional steering wheel is realized, the road feel simulation is realized, and the good road feel feedback torque can be realized through reasonable control of the output of the motor.
In the mechanical road feel simulation mode, the electromagnetic clutch 310 is energized, at this time, the electromagnetic coil 390 is energized and generates electromagnetic force to attract the armature 320 which is splined and slidably sleeved on the sun gear shaft 570, so that the armature 320 will abut against the splined end on the shaft section of the sun gear shaft 570, and therefore, the sun gear shaft 570 is disconnected from the motor reducer output shaft 210, and the sun gear shaft 570 can freely rotate relative to the motor reducer output shaft 210. In the mechanical road feel simulation mode, the driver is equivalent to the power source of the whole road feel simulation system. During steering, driver-input power is input to ring gear 530 through carrier 550, and rotation of ring gear 530 will cause rotation of sun gear 510 splined to sun gear shaft 570 due to the presence of the power coupling mechanism. The power output by the driver needs to make the gear ring 530 rotate, on one hand, the elasticity generated when the torsion spring 710 fixedly installed on the gear ring 530 rotates is overcome, on the other hand, the outer end of the nut 730 in the mechanical road feel simulation mechanism is provided with a gear and is meshed with the gear ring 530 in the planetary gear mechanism, so when the rotational motion of the gear ring 530 is input into the ball screw nut pair, the rotational motion is converted into the linear motion of the screw 740, and the screw 740 generates relative displacement when in the linear motion, so that the corresponding damping force is generated by the damper 720 to act on the gear ring 530 in the planetary gear mechanism, and the power input by the driver also needs to overcome the damping force, namely, the torsion spring 710 and the damper 720 in the mechanical road feel simulation mechanism generate feedback moment to act on the steering wheel in the steering process, and the road feel moment feedback in the steering process is realized;
In the mechanical road feel simulation mode, the driver does not need to input extra steering force in the steering return process; when the steering wheel rotates to a certain angle, the rotational movement of the gear ring 530 forces the torsion spring 710 to generate corresponding elastic deformation, so that the torsion spring 710 has certain elastic potential energy, so that the elastic potential energy accumulated by the torsion spring 710 is released during the steering return process, the generated elastic force forces the gear ring 530 to return to the initial position, and the steering wheel connected with the planet carrier 550 is further driven to return to the initial position, namely the steering wheel is automatically returned; and, when the elastic potential energy accumulated in the torsion spring 710 is released, the elastic force acting on the gear ring 530 will cause the gear ring 530 to return, and the movement of the gear ring 530 will cause the screw 740 to move relatively to the damper 720, so that the elastic force generated by the torsion spring will overcome the damping force generated by the damper 720 and the friction force in the transmission path of the whole road feel simulation system to return the steering wheel, thereby avoiding the shimmy phenomenon of the steering wheel at the middle position when the elastic force generated by the torsion spring 710 is singly used as the power for returning the steering wheel, and making the steering wheel return more stable.
In the electronic road feel simulation mode, the feedback moment transmitted to the driver is the sum of the feedback moment generated by the road feel simulation motor and the mechanical road feel simulation mechanism, when the road feel simulation motor and other relevant electronic elements are in failure, namely, the road feel simulation motor is switched to a mechanical backup system to work in the mechanical road feel simulation mode, the feedback moment transmitted to the driver is only generated by the mechanical road feel simulation mechanism, so that the road feel feedback fluctuates, but the scheme can still have the feedback moment acted on the driver when the road feel simulation motor and other relevant electronic elements are in failure in the steering process, namely, the dangerous situation of road feel loss cannot be generated, and the road feel feedback moment transmitted to the driver can still more ideally meet the ideal road feel feedback requirement of the driver under low speed.
In summary, the drive-by-wire steering road feel simulation system with mechanical redundancy of the invention can realize two working modes of electronic road feel simulation and mechanical road feel simulation, namely, the road feel simulation motor is utilized to regulate and transmit the total road feel feedback moment to a driver according to working conditions under the condition that electronic device elements necessary for the electronic road feel simulation work normally so as to meet the ideal road feel feedback requirement of the driver, and fault-tolerant control can be rapidly carried out under the condition that the electronic device elements are out of fault, the drive-by-wire steering road feel simulation system is switched to a backup system, and the road feel simulation motor does not generate moment any more, the steering wheel is only provided with a mechanical road feel simulation mechanism to generate torque and act on the steering wheel so that a driver can feel road feel feedback, namely, the steering wheel is switched to a mechanical road feel simulation mode, the road feel feedback is realized by utilizing elastic force generated by a torsion spring, damping force generated by a shock absorber and the like, the steering wheel is automatically corrected, meanwhile, the stroke of a piston rod in the shock absorber is reasonably designed, and the limit position of the steering wheel can be physically limited, so that the road feel simulation system for the drive-by-wire steering has a similar function with a traditional steering system, and is convenient for the driver to adapt to the emerging technology of the drive-by-wire steering. Preferably, once the electronic device element related to the electronic road feel simulation in the steering process fails, the invention can rapidly perform fault-tolerant control, and the system is switched to a backup system, namely, the system works in a mechanical road feel simulation working mode, namely, road feel feedback can be continuously provided in the steering process, and the moment fed back to a driver can fluctuate when switching to the mechanical backup system, so that the driver can not lose the necessary road feel, the reliability and the functional safety level of the system are improved to a certain extent, and the driving safety of the driver is ensured.
Although embodiments of the present invention have been disclosed above, it is not limited to the use in the description and embodiments, it is well suited to various fields of use for the invention, and additional modifications will readily occur to those skilled in the art, and therefore the invention is not limited to the specific details and illustrations shown herein, without departing from the general concepts defined in the claims and the equivalents thereof.
Claims (8)
1. A steer-by-wire road feel simulation system with mechanical redundancy, comprising:
a road feel simulation system shell;
the road sense simulation motor and the speed reducing mechanism thereof are used for generating feedback torque and acting on a driver so as to realize road sense feedback, automatic correction of the steering wheel and simulation limit;
the planetary gear mechanism is used for carrying out speed reduction and torque increase on the input torque of the road sense simulation motor and a speed reduction mechanism or a mechanical road sense simulation mechanism and outputting the torque to a driver so as to realize road sense simulation, and comprises the following components:
the sun gear shaft is rotatably supported in the road sense simulation system shell;
the sun gear is fixedly arranged on the sun gear shaft in a key connection manner;
the planet carrier is rotatably supported in the road feel simulation system shell;
The planetary wheel shafts are arranged in through holes distributed on the circumference of the planetary frame and are axially positioned through check rings;
the planet wheel is rotatably supported on the planet wheel shaft and is in external meshed transmission with the sun wheel;
the gear ring is rotatably supported on the sun gear shaft and is in meshed transmission with the planet gears; the mechanical road feel simulation mechanism is used for replacing simulated road feel moment to a driver through an elastic element and a damping element when an electronic device related to a road feel simulation system fails, and is used as a redundant backup of the road feel simulation motor and a speed reducing mechanism thereof, and comprises the following components:
the two ends of the nut are rotatably supported in the road sense simulation system shell, and gears are machined on the outer circle of the middle of the nut and meshed with the gear ring for transmission, so that the rotary motion of the gear ring is converted into the rotary motion of the nut;
the inner end of the screw rod is matched with a ball circulation roller path processed in the inner central inner hole of the nut through a group of balls to form an inner circulation ball screw nut pair, so that the rotary motion of the nut is converted into the linear motion of the screw rod;
the vibration absorber is arranged on the road sense simulation system shell through a mounting flange by a screw, and the screw rod and a piston rod of the vibration absorber are made into a whole, namely, the linear motion of the screw rod enables the piston of the vibration absorber to move in the vibration absorber, so that damping force is generated;
One end of the torsion spring is fixedly arranged on the gear ring, the other end of the torsion spring is arranged on the road feel simulation system shell, and a boss with an annular groove is processed on the road feel simulation system shell and is used for axially positioning and centrally positioning the torsion spring;
when the gear ring rotates, the torsion spring is elastically deformed to generate elastic force, and power is transmitted to an internal circulation ball screw nut pair formed by the nut and the screw rod to enable the screw rod to linearly move, so that the damper generates damping force;
the power coupling mechanism is used for reducing the planetary gear mechanism by one degree of freedom so that the two input ends of the planetary gear mechanism synchronously rotate at a fixed proportion of rotating speed to realize power coupling;
the electromagnetic clutch is arranged between the road feel simulation motor, the speed reducing mechanism of the road feel simulation motor and the power coupling mechanism and is used for controlling whether the power of the road feel simulation motor is input to the power coupling mechanism or not; in the steering-by-wire road feel simulation system with mechanical redundancy, in the steering process of a driver, no matter whether the road feel simulation motor works normally or not, the torsion spring and the vibration damper in the mechanical road feel simulation mechanism act and generate mechanical road feel simulation moment to act on the driver, so that the mechanical road feel simulation mechanism can still keep the road feel simulation moment even if the road feel simulation motor fails in the steering process.
2. The steer-by-wire road feel simulation system with mechanical redundancy of claim 1, wherein the road feel simulation system housing comprises:
the first shell is used for accommodating the road feel simulation motor, the speed reducing mechanism of the road feel simulation motor, the electromagnetic clutch and the damping element in the mechanical road feel simulation mechanism; a second housing for accommodating elastic elements in the planetary gear mechanism and the mechanical road feel simulation mechanism;
and the third shell is used for accommodating the power coupling mechanism.
3. The steer-by-wire road feel simulation system with mechanical redundancy of claim 1, wherein the road feel simulation motor and its reduction mechanism comprise:
the shell of the road sense simulation motor is fixed on the road sense simulation system shell, and the motor shaft of the road sense simulation motor is rotatably supported in the road sense simulation system shell;
the primary transmission pinion is installed on the motor shaft through key connection;
one end of the motor reducer output shaft is rotatably sleeved in the road feel simulation system shell, and the other end of the motor reducer output shaft is rotatably sleeved in the electromagnetic clutch shell;
the primary transmission large gear is installed on an output shaft of the motor reducer through key connection and is meshed with the primary transmission small gear for transmission, so that the speed and torque of the output power of the road feel simulation motor are reduced.
4. The steer-by-wire road feel simulation system with mechanical redundancy of claim 1, wherein the power coupling mechanism comprises:
the primary coupling pinion is fixedly installed on the sun gear in a key connection manner;
the power coupling shaft is rotatably supported in the road feel simulation system shell;
a primary coupling large gear fixedly installed on the power coupling shaft in a key connection manner and meshed with the primary coupling small gear for transmission, so that power from the sun gear shaft is transmitted to the power coupling shaft;
a secondary coupling pinion fixedly installed on the power coupling shaft in a key connection and engaged with the ring gear so as to transmit power from the power coupling shaft to the ring gear;
under the action of the power coupling mechanism, the fixed speed ratio synchronous rotation of the sun gear and the gear ring is realized, part of power transmitted to the sun gear shaft is transmitted to the planet gears through the sun gear, and the other part of power is transmitted to the gear ring through the power coupling mechanism and further transmitted to the planet gears, so that power coupling is realized, and finally, the power is output from the planet carrier.
5. The steer-by-wire road feel simulation system with mechanical redundancy of claim 1, wherein the electromagnetic clutch comprises:
the electromagnetic clutch shell is coaxially connected with the road sense simulation system shell through a screw;
an electromagnetic coil fixed in the electromagnetic clutch housing recess;
the armature is sleeved on the shaft diameter of the sun gear shaft in a sliding manner in a spline connection mode;
a torque adjusting ring which is connected with the sun gear shaft through threads;
one end of the spring is supported in the groove of the moment adjusting ring, and the other end of the spring is fixedly connected to the armature;
the spring positioning ring is connected and fixed on the sun gear shaft through a wedge key;
the friction plate is fixedly arranged on an output shaft flange of the motor reducer through a screw;
when the electromagnetic coil is powered off, the spring compresses the armature iron on a friction plate fixedly arranged on the motor reducer output shaft flange through self spring force, so that the motor reducer output shaft and the sun gear shaft are locked together, namely, the motor reducer output shaft and the sun gear shaft synchronously rotate at the same rotating speed; when the electromagnetic coil is electrified, electromagnetic force generated by the electromagnetic coil attracts the armature to axially slide away from the friction plate and abut against the spline tail end of the sun gear shaft, so that the axial connection between the sun gear shaft and the output shaft of the motor reducer is disconnected, namely the power transmission of the road feel simulation motor is disconnected, and the sun gear shaft can freely rotate relative to the output shaft of the motor reducer.
6. The steer-by-wire feel simulation system with mechanical redundancy according to claim 1, wherein the planet carrier of the planetary gear mechanism extends out of the feel simulation system shell, and the shaft end of the planet carrier is provided with an external spline and is in spline connection with a steering column tube connected with a steering wheel in an automobile steering system.
7. The steering-by-wire road feel simulation system with mechanical redundancy according to claim 1, wherein when a road feel simulation motor and related electronic component devices work normally, the electromagnetic clutch is powered off, the road feel simulation motor and a speed reducing mechanism thereof transmit torque output by the current running working condition to the planetary gear mechanism through the electromagnetic clutch and the power coupling mechanism, and the torque and the elastic force and the damping force generated by the mechanical road feel simulation mechanism are output to a steering wheel together to a driver, so that ideal road feel simulation is realized; when the road feel simulation motor and related electronic element devices are in failure, the electromagnetic clutch is electrified, and the road feel simulation motor and a speed reducing mechanism thereof are disconnected with the steering wheel; at the moment, the elastic force and the damping force generated by the mechanical road feel simulation mechanism act on the planetary gear mechanism and are output to the steering wheel to be given to a driver, so that the mechanical road feel simulation is realized.
8. The steering-by-wire road feel simulation system with mechanical redundancy according to claim 1 or 7, wherein the vehicle is designed to realize ideal road feel simulation by the combined action of the road feel simulation motor and the speed reducing mechanism thereof and the mechanical road feel simulation mechanism when running at high speed, and provides a larger moment feedback effect for a driver so as to meet the requirement of the driver on high-speed driving stability; the mechanical road feel simulation mechanism is designed to realize road feel simulation when the automobile runs at a low speed, the road feel simulation motor carries out micro-adjustment on feedback torque output to a driver, at the moment, a small torque feedback effect is provided for the driver so as to meet the light road feel requirement of low-speed steering expected by the driver, after the road feel simulation motor and related electronic element devices fail, the influence of inconsistency of the mechanical road feel simulation and ideal road feel simulation on the experience of the driver is minimum, and the driver can obtain relatively real road feel feedback when the automobile runs at a low speed so as to reduce the deterioration of driving safety and road feel experience influenced by misoperation.
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| CN115871773B (en) * | 2022-12-26 | 2024-06-25 | 清华大学 | Drive-by-wire steering road feel simulation system with failure redundancy and control method thereof |
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| CN112590921B (en) * | 2020-12-25 | 2022-02-08 | 吉林大学 | Intelligent automobile redundant steer-by-wire device and control method thereof |
| CN215706606U (en) * | 2021-06-22 | 2022-02-01 | 中国第一汽车股份有限公司 | Steering column of electric adjustment |
| CN113895511B (en) * | 2021-10-09 | 2022-09-16 | 南京航空航天大学 | Electro-hydraulic integrated steering system and multi-parameter coupling optimization method thereof |
| CN216185449U (en) * | 2021-11-09 | 2022-04-05 | 安徽理工大学 | A drive-by-wire a steering system for heavy commercial car |
| CN114212144A (en) * | 2021-11-24 | 2022-03-22 | 中汽创智科技有限公司 | Vehicle steering system |
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2022
- 2022-04-29 CN CN202210475056.7A patent/CN114802423B/en active Active
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