KR20120041555A - Vehicle with multiple axis driven independently - Google Patents

Abstract

PURPOSE: An independent multi-axis drive type vehicle improves the reliability of fault diagnosis by diagnosing the fault based on the relation of the detected value from the yawing rate sensor and calculated yawing rate value form the other sensors. CONSTITUTION: An independent multi-axis drive type vehicle comprises a control input unit, a driving control unit, an operating unit, a preprocessing unit, and a fail safety control unit. The control input unit is input the control input. The control input includes at least one value among the steering input and the acceleration input and the brake input. The driving control unit controls and drives some part of wheels according to the control input. The operating unit operates the vehicles through the control input of the driving control unit. The operating unit comprises a sensor module. The sensor module comprises a yawing rate sensor and a plurality of sensors. The yawing rate sensor detects the yawing rate of a vehicle. A plurality of sensors detects the operating state of a vehicle. The preprocessing unit generates the yawing rate by detecting the signal from a yawing rate sensor, and calculates the yawing rate during the operating state and control input state. The fail safety control unit diagnoses the failure of sensors based on the detected yawing rate and calculated yawing rate.

Description

Vehicle with multiple axis driven independently

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an independent multi-axis drive type vehicle, and more particularly, to an independent multi-axis drive type vehicle in which a plurality of wheels are mounted and which can apply different driving and / or braking inputs to each wheel.

Recently, there is an increasing demand for driving stability of a vehicle and convenience of a driver while driving. In addition, studies on active safety systems and driver assistance systems of vehicles are being actively conducted.

Active safety braking systems include Electronic Stability Control (ESC). In addition, an active steering system includes AFS (Active Front Steering). In addition, the driving force control system includes a TCS (Traction Control System) for controlling the torque of the engine, and DYC (Direct Yaw Control) using a differential axle device.

Active safety devices detect the vehicle's condition from a yaw-rate sensor, lateral acceleration sensor, and wheel speed sensor. At this time, if it is determined that the state of the vehicle is unstable, the necessary control input is calculated and applied so that the vehicle is in a stable state.

Meanwhile, in an electric vehicle or a hybrid vehicle, at least some of the wheels may be driven using a motor. In this case, different driving inputs and / or braking inputs may be applied to at least some of the wheels.

SUMMARY OF THE INVENTION An object of the present invention is to provide an independent multi-axis drive type vehicle capable of improving reliability of failure diagnosis by diagnosing a failure from the relationship between the measured value of the yaw speed sensor and the estimated yaw speed estimated from another sensor. do.

The present invention, each of the plurality of wheels capable of independent driving; A steering input unit configured to receive a steering input including at least one of a steering input, an acceleration input, and a braking input; A plurality of sensors including a yaw rate sensor for detecting a yaw rate and detecting an operating state of the vehicle; A preprocessor configured to process a signal of the yaw rate sensor to generate a yaw rate measured value, and to estimate a yaw rate estimated value from at least a portion of the steering input and the operating state; And a failure safety control unit for diagnosing a failure of at least some of the sensors from the yaw speed measurement value and the yaw speed estimate value.

A drive module including an in-wheel motor, the rotary shaft being directly connected to the rotary shaft of the wheel to drive the wheel, a braking module including a brake installed on each of the wheels, and a link with at least one of the wheels. It may be further provided with a steering module including a steering motor connected to adjust the steering angle.

The driving controller may further include a driving controller configured to control at least some of the wheels according to the steering input.

The sensor may include a steering angle sensor for detecting a steering angle of the vehicle, a lateral acceleration sensor for detecting a lateral acceleration of the vehicle, a longitudinal speed sensor for detecting a longitudinal speed of the vehicle, and wheel rotation of at least some of the wheels It may be provided with a wheel speed sensor for detecting the speed.

In the pre-processing unit, the steering angle measurement value by processing the signal of the steering angle sensor, the lateral acceleration sensor signal processing the lateral acceleration measurement value, the longitudinal speed measurement value by processing the signal of the longitudinal speed sensor, and the wheel The signal of the speed sensor may be processed to generate at least some of the wheel speed measurements.

In the preprocessor, from the steering input, reflecting the longitudinal velocity, the lateral velocity, and the dynamics model of the vehicle, from the first estimated value, the steering angle measurement value, the longitudinal velocity of the vehicle, the lateral velocity And a second estimated value generated by reflecting a dynamic model, a third estimated value generated from the lateral acceleration measurement value and the longitudinal speed measurement value, and a plurality of fourth estimated values generated from the plurality of wheel speed measurement values, respectively. At least some of them may be produced.

The failure safety control unit may diagnose a failure of at least some of the sensors from a combination of a plurality of residuals generated by differences of some of the first to fourth estimates, respectively.

If some of the sensors are diagnosed to have failed, the estimated value or yaw rate measurement estimated from the sensor diagnosed as failed may be substituted for the estimated value or yaw rate measured from another sensor diagnosed as not broken. have.

When the yaw rate sensor is diagnosed to have failed, the second estimated value estimated from the steering angle measurement may be replaced with the yaw rate measurement.

The failsafe control unit may determine whether the brake module is broken from the longitudinal speed of the vehicle, the braking input, and the wheel acceleration.

The wheel acceleration may be estimated and generated by the Kalman filter from the wheel speed of the wheel.

The failure safety controller may diagnose whether the driving motor is broken by comparing the driving input torque input to the driving motors of the wheels from the driving controller with the measured torque measured by the driving motor.

When the failure safety control unit diagnoses a failure of at least some of the driving module, the braking module, and the steering module, the driving control unit may control to distribute the torque to the wheels to travel to the driving limit capability.

The user can select whether or not to stop the vehicle safely when the vehicle exceeds the driving limit capability.

According to the independent multi-axis drive type vehicle according to the present invention, the reliability of the failure diagnosis can be improved by diagnosing the failure from the relationship between the measured value of the yaw speed sensor and the estimated yaw speed estimated from another sensor.

1 is a diagram schematically illustrating an independent multi-axis driven vehicle having an eight wheel structure according to an exemplary embodiment of the present invention.
FIG. 2 is a block diagram schematically illustrating a control structure inside the independent multi-axis drive type vehicle of FIG. 1.
3 is a diagram schematically illustrating a structure for diagnosing a failure of each of the sensors and the steering module from the steering input and the measured values by the sensors in the independent multi-axis driven vehicle of FIG. 1.
4 is a table schematically showing an embodiment of a relationship between failure of each residual and respective sensors and a steering module in the structure of diagnosing a failure of FIG. 3.
FIG. 5 is a view schematically illustrating a structure for diagnosing a failure of a braking module in the independent multi-axis drive type vehicle of FIG. 1.
FIG. 6 is a diagram schematically illustrating a structure for diagnosing a failure of a driving module in the independent multi-axis driving type vehicle of FIG. 1.
FIG. 7 is a graph showing a trend of a yaw speed measured value when a steady state of a yaw speed sensor and a failure occur in the independent multi-axis drive type vehicle of FIG. 1.
FIG. 8 is a graph illustrating a case in which a yaw speed measurement value is replaced with another estimated value when a yaw speed sensor fails in the independent multi-axis drive type vehicle of FIG. 1.
FIG. 9 is a graph showing a trend of a steering angle measurement value when a steady state of a steering angle sensor and a failure occur in the independent multi-axis drive type vehicle of FIG. 1.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a schematic structure of an independent multi-axis driven vehicle 10 having an eight wheel structure according to an exemplary embodiment of the present invention. 2 schematically illustrates a control structure inside the independent multi-axis drive type vehicle 10 of FIG. 1.

The independent multi-axis drive type vehicle 10 may apply different driving and braking force to each wheel 11 of the vehicle configured to be independently driven using the in-wheel motor 12. Thus, it is possible to enable a turning motion beyond the mechanically possible range for the driver's steering input.

The host controller 210 may calculate the yaw speed for the steering input of the driver and determine the overall longitudinal force and yaw moment of the vehicle to follow the driver's steering input. The lower controller 220 may determine the driving force and the braking force required for each wheel 11 and may control the slip of the wheel 11 and the ground not to exceed the set maximum slip ratio. Therefore, it is possible to improve energy efficiency and to improve driving performance and safety.

Meanwhile, in order to improve driving stability of the vehicle and convenience of the driver while driving, an active safety system and a driver assistance system of the vehicle may be introduced. To this end, ESC (Electronic Stability Control) may be applied as an active safety braking system. In addition, as an active steering system, AFS (Active Front Steering) may be applied.

In addition, the driving force control system may include a TCS (Traction Control System) for controlling the torque of the engine and DYC (Direct Yaw Control) using a differential axle device.

The active safety device detects the state of the vehicle from the yaw-rate sensor, the steering angle sensor, the lateral acceleration sensor, the longitudinal speed sensor, and the wheel speed sensor mounted on the vehicle, and the state of the vehicle is unstable. If it is determined that the necessary control input can be calculated and applied to the vehicle to be in a stable state.

The independent multi-axis drive type vehicle 10 according to an embodiment of the present invention may be applied to an electric drive or hybrid wheel type independent multi-axis drive type armored vehicle such as four wheels, six wheels, or eight wheels. Independent multi-axis drive type vehicle 10 can utilize the structural advantages, it is possible to distribute the driving and braking force to enable the driving beyond the limit of the turning movement by the mechanical method.

To this end, a target longitudinal speed and a target yaw speed for the purpose of maneuverability, transverse running stability, etc. of the vehicle may be determined, and an optimal solution of driving and braking force of each wheel for realizing the vehicle may be obtained and applied as an input.

Referring to the drawings, the independent multi-axis drive type vehicle 10 may independently drive and / or determine a driving and / or braking input applied to at least some of the wheels with respect to the steering input. To this end, a plurality of wheels 11 are mounted on the independent multi-axis drive type vehicle 10, and each wheel 11 may be independently driven. To this end, each wheel 11 may be equipped with an in-wheel motor 12.

The in-wheel motor 12 may drive the wheel 11 by the rotation axis is directly connected to the rotation axis of the wheel (11). The in-wheel motor 12 may be directly connected to the wheel through the reduction gear without connecting a separate transmission mechanism to each wheel 11.

In this case, the independent multi-axis driven vehicle 10 may be an electric vehicle or a hybrid vehicle. When the independent multi-axis drive type vehicle 10 is a hybrid vehicle, the in-wheel motor 12 installed in each wheel 11 can be driven by the electric power obtained from the output of the engine.

In addition, each wheel 11 may be equipped with a mechanical brake 13. The mechanical brake 13 can be a hydraulic brake with excellent braking performance. Regenerative braking on the characteristics of the in-wheel motor 12 mounted on each wheel 11 is possible. Braking of the vehicle 10 can be achieved efficiently using the in-wheel motor 12 and the mechanical brake 13.

At this time, when braking is not possible only by regenerative braking according to the braking force and driving conditions through the motor, the mechanical brake 13 mounted on each wheel may be operated to improve braking performance of the vehicle.

In the embodiment shown in FIG. 1, the in-wheel motor 12 and the mechanical brake 13 can be individually mounted to each of the wheels 11. However, the present invention is not limited thereto, and an embodiment in which the in-wheel motor 12 and / or the mechanical brake 13 are mounted only on some of the wheels 11 may be possible.

Meanwhile, the vehicle 10 may control mechanical steering by the steering motor 14. The steering motor 14 may be connected to at least one of the wheels 11 by a link to adjust the steering angle of the vehicle 10.

The independent multi-axis driven vehicle 10 includes a steering input unit 100; Driving control unit 200; Operating part 300; Pre-processing unit 400; And a failsafe control unit 500.

The steering input unit 100 receives a steering input including at least one of a steering input, an acceleration input, and a braking input. The driving controller 200 may control driving and / or braking of at least some of the wheels 11 according to the steering input. The operation unit 300 operates the vehicle 10 by a control command of the travel control unit 200.

The operation unit 300 includes a sensor module 340 including a plurality of sensors. The sensor module 340 may include a yaw rate sensor that detects a yaw speed of the vehicle 10, and may include a plurality of sensors that detect an operating state of the vehicle 10.

The preprocessor 400 may generate a yaw rate measurement value by processing a signal of the yaw rate sensor, and estimate the yaw rate estimated value from at least some of the steering input and the operating state. The failsafe control unit 500 may diagnose a failure of at least some of the sensors from the yaw speed measurement value and the yaw speed estimate value.

Therefore, other factors diagnose the fault from the relationship between the measured value of the yaw rate sensor and the estimated yaw rate estimated from another sensor, thereby improving the reliability of the fault diagnosis.

The traveling control unit 200 may include an upper controller 210 and a lower controller 220.

The host controller 210 determines the driving control strategy of the vehicle in consideration of the driving conditions of the vehicle, and determines at least one of a mechanical steering angle, a target yaw moment, a target longitudinal force, and a target wheel speed from the steering input according to the driving control strategy. A target control amount including either can be determined.

The lower controller 220 may determine the wheel torque of each of the wheels 11 from the target control amount determined by the upper controller 210 according to the driving control strategy. In this case, by distributing the driving and braking inputs optimized for each in-wheel motor 12 according to the driving conditions, the driving performance may be increased while maintaining the driving stability of the vehicle even in various driving situations including high speed turning and field driving.

The operation unit 300 may include a steering module 310, a driving module 320, a braking module 330, and a sensor module 340.

The steering module 310 may have a steering motor 14. The steering module 310 may adjust the mechanical steering angle of the vehicle 10 by connecting one or a plurality of steering motors 14 by a link to adjust angles of steering wheels. At this time, the steering motor 14 may be connected to the wheels 11 through a link in a different structure depending on the structure of the vehicle.

In the case of an independent multi-axis driven vehicle having a four-wheel structure, steering angles of the front wheels can be adjusted. In the case of the independent multi-axis driven vehicle 10 having an 8-wheel structure and the independent multi-axis driven vehicle having a 6-wheel structure, steering angles of the front wheels and the middle wheels can be operated. In this case, the steering angle of each wheel 11 can be driven independently as needed. Therefore, there is little drive loss for steering drive of a vehicle, and it becomes possible to drive the steering motor 14 efficiently.

Meanwhile, the steering input may be input through the steering handle. The acceleration input may be input through an acceleration pedal. The braking input may be input via the brake pedal.

The drive module 320 may include the in-wheel motor 12 of FIG. 1. In addition, the braking module 330 may include the mechanical brake 13 of FIG. 1. The sensor module 340 detects an operating state of the vehicle 10 and may include a plurality of sensors.

The sensor module 340 may include a yaw-rate sensor, a steering angle sensor, a lateral acceleration sensor, a longitudinal speed sensor, a wheel speed sensor, and the like.

A yaw-rate sensor detects a yaw speed of the vehicle 10. The steering angle sensor detects a steering angle of the vehicle 10. The lateral acceleration sensor detects lateral acceleration of the vehicle 10. The longitudinal speed sensor detects the longitudinal speed of the vehicle 10. The wheel speed sensor senses the wheel rotation speed of at least some of the wheels 11.

The preprocessor 400 may generate various measurement values by processing the measurement signals detected by the sensors of the sensor module 340. In addition, the preprocessor 400 may estimate the yaw speed estimate from the steering input and the operating state.

To this end, the preprocessor 400 detects the sensors of the sensor module 340 and processes the measured signals to generate various measured values. The state of estimating the yaw rate estimated value from the signal processor 410 and the steering input and the operating state is generated. An estimator 420 may be provided.

The measurement values generated by the preprocessor 400 may include at least some of a steering angle measurement value, a lateral acceleration measurement value, a longitudinal speed measurement value, and a wheel speed measurement value.

The steering angle measurement may be generated by processing the measurement signal of the steering angle sensor. The lateral acceleration measurement value may be generated by processing the measurement signal of the lateral acceleration sensor. The longitudinal speed measurement can be generated by processing the measurement signal of the longitudinal speed sensor. The wheel speed measurement may be generated by processing a measurement signal of the wheel speed sensor.

The preprocessing unit 400 may obtain a yaw rate estimate value from various measured values and generate residuals of each of the yaw rate measured value and the yaw rate estimated values by a failure diagnosis structure as illustrated in FIG. 3. . The failsafe control unit 500 may diagnose whether the respective sensors and the steering model have failed according to the values of the residuals.

In addition, the failure safety controller 500 may determine whether the brake module is broken from the longitudinal speed of the vehicle, the brake input, and the wheel acceleration. In addition, the failure safety controller 500 may diagnose the failure of the driving motor by comparing the driving input torque input to the driving motors of the respective wheels with the measured torque measured by the driving motor.

Therefore, it is possible to diagnose and cope with failures of sensors and driving, braking and steering modules in the field driving and combat situations of electric vehicles or hybrid wheel type independent multi-axis driven armored vehicles. Therefore, the reliability of the independent multi-axis drive type vehicle 10 can be improved.

The host controller 210 calculates and sets a target behavior of the vehicle with respect to the driver's steering input. In addition, the upper controller 210 may determine a control input applied to the lower controller 220 to follow the target behavior.

In this case, the control input may be a longitudinal force of the entire vehicle for torque control and a target wheel speed for target yaw moment or speed control. The control input may also be a dual steering control input of mechanical steering for compound steering and / or wheel torque steering required for each wheel 11.

The lower controller 220 applies hydraulic pressure according to the amount of tire force distribution required for each wheel to reflect the control input determined by the upper controller 210 to the vehicle 10, and the amount of regenerative braking generated by each in-wheel motor 12. The combined brake control to determine the brake amount of the mechanical brake 13 to be generated, and the wheel slip control for running stability of the vehicle when the slip of each wheel 11 occurs excessively.

The preprocessor 400 may process the measurement signal input from the sensors, estimate the state of the variables required for the control, and generate information required by the upper controller 210 and / or the lower controller 220.

The host controller 210 may determine the driving control strategy of the vehicle according to the driving condition of the vehicle. In this case, the driving condition may include a normal driving mode, an in-situ turning mode, and a sharp turning driving mode.

In the normal driving mode, the vehicle 10 is controlled by a driving control strategy including at least one of mechanical steering, combined braking, stability control, and slip control. In situ swing mode allows the vehicle 10 to be controlled by a compound steering from which mechanical steering has been removed.

In the rapid driving mode, the vehicle 10 is controlled by a driving control strategy including at least one of compound steering, compound braking, stability control, and slip control.

Mechanical steering is to adjust the steering angle of the steering wheels which are linked by the steering motor 14 to the steering motor 14. The compound steering can be a control made by a combination of mechanical steering and wheel torque steering of each wheel 11.

Normal travel refers to a turning radius turning drive with mechanical steering. Therefore, additional steering control other than mechanical steering is unnecessary in normal driving. In addition, when a deceleration situation occurs during driving, the regenerative braking amount of the in-wheel motor 12 may be determined, and complex braking control may be performed to distribute the hydraulic braking force and the regenerative braking force.

Since normal driving includes high speed situations, stability control of the vehicle may be included. In addition, slip control may be included to improve steering performance.

In-situ swinging refers to the movement in place without longitudinal movement. In this case, only yaw motion is required without longitudinal velocity. Thus, mechanical steering is excluded and yaw moments can be generated through differential torque distribution on each wheel 11 by a compound steering control strategy.

Sharp turning is necessary for driving with small turning radii which is not possible with mechanical steering. In this case, it is possible to overcome the limitation of mechanical steering by utilizing the turning performance to the maximum by mechanical steering and at the same time compensating for additional moments through the differential distribution of wheel driving force of the compound steering strategy.

The compound steering control strategy may allow the vehicle 10 to be controlled by at least one control strategy of mechanical steering, stability control, wheel torque control, and wheel speed control according to the driving situation. At this time, the compound steering control strategy is a general road high speed situation (30kph or more) in the first mode, a general road medium speed situation (10kph to 30kph) in the second mode, a general road low speed situation (5kph to 10kph) in the third mode, and It can be created by dividing the low-speed situation of off-road (0kph ~ 5kph).

Meanwhile, the steering control strategy may be determined by the complex steering control strategy according to the driving situation. In the example shown in the table, road conditions are divided into general roads and off roads, and speed conditions are divided into high speed, medium speed, and low speed. At this time, the high speed is more than 30km per hour, the medium speed is between 10km and 30km per hour, the low speed is between 5km and 10km per hour, the off-road low speed is less than 5km.

At this time, the limit of the mechanical steering angle was defined as 10 degrees, it can be made to create the target yaw moment through the compound steering control when the driver requires more steering angle. In a low speed situation, the target value may be satisfied by the wheel speed control. This is because the wheel speed control is more robust than the wheel torque control in the off-road low speed situation.

In the medium speed situation, the target yaw moment is satisfied by the wheel torque control, but the speed control can be performed in parallel with the wheel condition. This is to prevent a phenomenon in which the slip ratio diverges to the wheel having a large wheel slip angle. In the high-speed situation, the stability of the vehicle can be ensured by controlling the stability control concept rather than the compound steering concept in normal driving (less than 10 degrees steering angle).

Here, the steering control strategy may be formulated to be based on mechanical steering and stability control (DYC, Direct Yaw Control) in the general road high speed situation. In addition, the steering control strategy can be formulated by the mechanical steering and wheel torque control in the normal road medium speed situation.

In normal road low speed situations, a steering control strategy can be formulated to combine mechanical steering with wheel torque control and wheel speed control. At this time, the outer wheel may be controlled by the wheel torque control, the inner wheel may be steered by the wheel speed control. In off-road low speed situations it can be steered by wheel speed control on both the inner and outer wheels without mechanical steering.

Meanwhile, when the failure control unit 500 diagnoses a failure of at least some of the steering module 330, the driving module 320, and the braking module 330, the wheels 11 may be used. The torque can be distributed to control the driving to the driving limit capability.

At this time, the user can select whether or not to stop the vehicle safely when driving beyond the driving limit capability.

Therefore, even when at least some of the steering module 330, the driving module 320, and the braking module 330 fail, the vehicle 10 is stably controlled, thereby improving the robustness, reliability, and stability of the vehicle 10. Can be improved.

3 shows a structure for diagnosing the failure of each of the sensors and the steering module from the steering input and the measured values by the sensors in the independent multi-axis driven vehicle 10. FIG. 4 is a table showing an embodiment of a relationship between failure of each residual and respective sensors and a steering module in a structure for diagnosing a failure of the vehicle 10.

Referring to the drawings, the preprocessing unit 400 includes a steering input, a steering angle measurement value, a lateral acceleration measurement value, a longitudinal speed measurement value, and a wheel speed measurement value based on a first estimated value, a second estimated value, a third estimated value, and a plurality of values. Some of the fourth estimates may be generated. Here, the first estimate value, the second estimate value, the third estimate value, and the plurality of fourth estimate values may be yaw velocity estimates estimated from the steering command or the respective measured value, respectively.

The first estimate may be generated from the steering input, reflecting the longitudinal velocity, the lateral velocity, and the dynamics model of the vehicle. In addition, the second estimate may be generated from the steering angle measurement to reflect the longitudinal speed, the lateral speed, and the dynamics model of the vehicle.

The third estimate may be generated from the lateral acceleration measurement and the longitudinal speed measurement. The fourth estimates may each be generated from a plurality of wheel speed measurements.

Each of the first estimate value and the second estimate value may be estimated and generated by the two degrees of freedom bike models 31 and 32 defined by Equation 1 below.

Here, β is the value obtained by dividing the lateral velocity by the longitudinal velocity, γ is the yaw velocity, and each of the determinants represented by the a variable and the determinants represented by the b variable are values determined by the vehicle dynamics model.

The third estimated value may be generated by dividing the lateral acceleration measurement value from the longitudinal speed measurement value as shown in FIG. 33. In addition, the fourth estimated values may be obtained by dividing the difference in linear speeds of both wheels by a value th corresponding to 1/2 of the roundness corresponding to the distance between the tire centers, as shown in FIG. 34. In this case, the fourth estimated values may be obtained by the number corresponding to 1/2 of the number of wheels.

In addition, the preprocessor 400 may obtain residuals r1 to r9 obtained by the difference between the yaw velocity measured value and the first to fourth estimated values, as shown in FIG. 35. The failsafe control unit 500 may diagnose a failure of at least some of the steering driver and / or the sensors from a combination of a plurality of residuals generated by the differences of some of the first to fourth estimates, respectively.

The failure safety controller 500 may diagnose the failure of the steering module 310 and the sensor module 340 by comparing the residuals r1 to r9 with respective reference values. In this case, the failure of the steering module 310 and the sensor module 340 may be determined by a combination of whether the respective residuals r1 to r9 are larger than the respective reference values. Here, it may be determined that there is a problem when each of the residuals r1 to r9 is larger than each reference value.

Diagnosing whether a component has failed from each of the residuals r1 to r9 may be performed by the same method as in the embodiment of the table of FIG. 4. For example, when the residual r1 and the residual r2 are larger than the reference value and the residuals r3 to r9 are smaller than the reference value, it may be determined that the steering driver, for example, the steering motor of the steering module 310 has failed.

Meanwhile, when some of the sensors are diagnosed to have failed, the preprocessor 400 estimates or estimates from the sensors diagnosed as having failed with an estimated value estimated from another sensor diagnosed as not broken or a measured yaw rate. You can replace the speed measurement.

Therefore, even when some sensors fail, by using the values estimated by other sensors instead, it is possible to improve the performance of the fault diagnosis and improve the reliability.

As an example, when the yaw speed sensor is diagnosed to have failed, the second estimated value estimated from the steering angle measurement may be replaced with the yaw speed measurement. FIG. 8 illustrates the yaw rate by the simulation result when the yaw rate measurement value is replaced by a second estimated value when the yaw rate sensor is diagnosed to have failed.

In the graph of Fig. 7, the shape of the speed graph 72 in the failure state in which the speed sensor is broken is suddenly 0 deg at 4 seconds with respect to the shape of the speed graph 71 in the normal state in which the speed sensor is not broken. fall off at / sec. However, as shown in the graph of FIG. 8, when the yaw speed measurement value is replaced by the second estimated value, it is shown that the yaw rate graph 82 in the fault state almost coincides with the steady state yaw rate graph 81.

Meanwhile, when the steering module 310 is broken in FIG. 9, the steering measurement value has a failure state graph 92, and is different from the failure state normal graph 91. In this case, when a failure of the steering module 310 occurs, the steering module may be configured by using a difference between the first estimated value corresponding to the yaw speed estimated value by the steering input and the second estimated value corresponding to the yaw speed estimated value by the steering angle measurement value. The failure of 310 can be diagnosed.

FIG. 5 schematically illustrates a structure for diagnosing a failure of the braking module 330 in the independent multi-axis driven vehicle 10.

Referring to the drawings, the failsafe control unit 500 of FIG. 2 may determine whether the braking module 330 has failed from the longitudinal speed, the braking input, and the wheel acceleration of the vehicle 10. As a specific embodiment, when braking has a value close to zero in the longitudinal velocity, it may be determined to be normal. In the case where the longitudinal speed is not close to zero at the time of braking, even when a braking input is applied, it may be determined that the wheel acceleration estimate at each wheel 11 does not fall below the reference value.

Here, the wheel acceleration estimate may be generated by the Kalman filter estimated from the wheel rotational speed of each wheel (11). When a failure is found, emergency braking may be performed by the driving control unit 200 by an auxiliary brake or a motor according to a driver's selection.

Therefore, even when a failure occurs in the braking module 330, by diagnosing whether a failure of the braking module 330 occurs and making emergency braking, the reliability of the driving of the vehicle 10 may be improved.

6 schematically illustrates a structure for diagnosing a failure of the driving module 320 in the independent multi-axis driven vehicle 10.

Referring to the drawings, the failsafe control unit 500 of FIG. 2 may diagnose the failure of the drive motor 61 by comparing the drive input torque and the measured torque. The driving input torque may be input from the driving controller 200 to the driving motor 61, for example, the in-wheel motor 12, of each of the wheels 11.

The measurement torque can be measured at the drive motor 61. The measured torque may be measured by a torque value sent from the motor controller 62 of the corresponding drive motor 61 based on the analog current signal. In this case, the torque value may be measured as a current signal.

At this time, the motor controller 62 may send a torque command in the form of a command analog current signal to the drive motor 61. In addition, the motor controller 62 can measure the measured torque of the drive motor 61 in the form of a measured current signal. In addition, the motor controller 62 may measure the wheel angular velocity of the drive motor 61.

In this case, the failure safety controller 500 may receive the measured torque and the wheel angular velocity to diagnose whether the driving module 330 has failed. In addition, the failure safety controller 500 may control to drive within the driving limit capability of the driving module when the driving module 330 is diagnosed as a failure. In addition, the vehicle 10 can be safely stopped when traveling beyond the driving limit capability.

Therefore, even when a failure occurs in the drive module 320, by diagnosing whether a failure of the drive module 320 occurs and ensuring safe driving, the reliability of the driving of the vehicle 10 can be improved.

According to the present invention, the reliability of the fault diagnosis can be improved by diagnosing the fault from other factors from the relationship between the measured value of the yaw rate sensor and the estimated yaw rate estimated from another sensor.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is merely an example, and those skilled in the art may realize various modifications and equivalent other embodiments therefrom. I can understand. Accordingly, the true scope of protection of the present invention should be determined only by the appended claims.

10: vehicle, 11: wheel,
12: in-wheel motor, 13: mechanical brake,
14: steering motor, 100: control input,
200: driving control unit, 210: upper controller,
220: sub-controller, 300: operating part,
400: preprocessor, 500: failsafe control.

Claims (14)

A plurality of wheels each capable of independent driving;
A steering input unit configured to receive a steering input including at least one of a steering input, an acceleration input, and a braking input;
A plurality of sensors including a yaw rate sensor for detecting a yaw rate and detecting an operating state of the vehicle;
A preprocessor configured to process a signal of the yaw rate sensor to generate a yaw rate measured value, and to estimate a yaw rate estimated value from at least a portion of the steering input and the operating state;
And a failure safety control unit for diagnosing a failure of at least some of the sensors from the yaw speed measurement value and the yaw speed estimate value. The method of claim 1,
A driving module including an in-wheel motor having a rotating shaft directly connected to the rotating shaft of the wheel to drive the wheel;
A braking module including a brake installed on each of the wheels, and
And a steering module including a steering motor connected to at least one of the wheels to adjust a steering angle. The method of claim 1,
And a travel controller for controlling at least some of the wheels in response to the steering input. The method of claim 1,
The sensor,
A steering angle sensor for detecting a steering angle of the vehicle;
Lateral acceleration sensor for detecting the lateral acceleration of the vehicle,
A longitudinal speed sensor for sensing a longitudinal speed of the vehicle, and
And a wheel speed sensor for detecting a wheel rotation speed of at least some of the wheels. The method of claim 4, wherein
In the pretreatment unit,
Steering angle measurement value by processing the signal of the steering angle sensor,
Transverse acceleration measurement value by processing the signal of the lateral acceleration sensor,
A longitudinal speed measurement value by processing the signal of the longitudinal speed sensor, and
And at least a portion of the wheel speed measurement value by processing the signal of the wheel speed sensor. The method of claim 5,
In the pretreatment unit,
A first estimated value generated from the steering input, reflecting a longitudinal velocity, a lateral velocity, and a dynamics model of the vehicle,
A second estimated value generated from the steering angle measurement, reflecting the longitudinal speed, the lateral speed, and a dynamics model of the vehicle,
A third estimated value generated from the lateral acceleration measurement and the longitudinal speed measurement, and
And independently generate at least some of the plurality of fourth estimates, each generated from a plurality of wheel speed measurements. The method of claim 6,
And wherein the failsafe control unit diagnoses a failure of at least some of the sensors from a combination of a plurality of residuals produced by the differences of some of the first to fourth estimates, respectively. The method of claim 7, wherein
In the event that some of the sensors are diagnosed to have failed, an independent value that replaces the estimated or yaw rate measurement estimated from the sensor diagnosed as failed with an estimate or yaw rate estimate estimated from another sensor diagnosed as not broken Multi-axis driven vehicle. The method of claim 8,
And a second estimated value estimated from the steering angle measurement value with the yaw speed measurement value when the yaw speed sensor is diagnosed to have failed. The method of claim 2,
And the failsafe control unit determines whether the braking module has failed from the longitudinal speed, the braking input, and the wheel acceleration of the vehicle. The method of claim 10,
And the wheel acceleration is generated by the Kalman filter estimated from the wheel speed of the wheel. The method of claim 3,
And the fault safety control unit diagnoses a failure of the drive motor by comparing a drive input torque input to the drive motors of the wheels from the travel controller and a measured torque measured by the drive motor. The method of claim 3,
When the failure safety control unit diagnoses a failure of at least a part of a driving module, a braking module, and a steering module, an independent multi-axis drive type vehicle which controls the driving control unit to distribute the torque to the wheels to travel to a driving limit capability. . The method of claim 13,
The independent multi-axis drive type vehicle which enables a user to select whether to stop a vehicle safely, when the drive exceeds a driving limit capability.

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