JP2010036728A - Vehicle steering controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicle steering controller capable of appropriately performing the control of vehicle's behavior based on the control requirement from other control units, even if the current magnitude to an assist motor is restricted so as to prevent overheating and so forth of the assist motor and its drive circuit. <P>SOLUTION: A current limiting performing section 203 sends current limiting command to a motor current determination section 202 and control preference judging section 205 in response to the driving state of the driving system for the assist motor 102. A correction torque command value calculation unit 206, when a current limiting is being imposed on the motor current determination section 202 by the current limiting performing section 203, sends a limitation alteration command to the motor current determination section 202 together with a correction torque command value so as to cause a current of correction torque command value exceeding the current limiting amount to be output from the motor current determination section 202 to the assist motor 102. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a vehicle steering control device that controls driving of an assist motor of an electric power steering device in accordance with a driver's steering operation.

  A general integrated control device includes a plurality of ECUs such as an electric power steering control ECU (Electronic Control Unit) and a skid prevention control ECU. In such an integrated control apparatus, a plurality of ECUs send and receive control requests to each other, and the plurality of ECUs cooperate with each other to control the behavior of the vehicle (see, for example, Patent Document 1).

  Further, in the conventional vehicle steering control device using the cooperative control technology of the integrated control device as described above, when a predetermined condition is satisfied in order to prevent overheating of the assist motor and its drive circuit in the electric power steering device. In addition, the amount of current to the assist motor is limited. When the electric power steering control ECU receives a control request from another control ECU in a state where the current amount is limited in this way, the maximum execution amount is calculated within the limited range, and the limit is limited. The assist control is executed within the specified range (see, for example, Patent Document 2).

Japanese Patent No. 3898323 JP 2005-225340 A

  In the conventional vehicle steering control device as shown in Patent Document 2, the electric power steering control ECU calculates the range of the steering angle that can be executed by the assist motor as an executable control amount. Then, the electric power steering control ECU transmits the executable control amount to another external vehicle behavior control device. When the electric power steering control ECU determines that the required torque due to the control request from the outside cannot be executed, the steering angle and assist torque that can be actually executed are calculated and the information is returned to the other ECUs. Therefore, the vehicle steering control device controls only the controllable amount of the required torque from the outside, and other control devices substitute control the other control. That is, the behavior of the vehicle is controlled by another ECU supplementing the control amount that cannot be executed by the electric power steering device.

  However, the conventional vehicle steering control device as described above performs control in situations where behavior control with a relatively high degree of urgency is required, for example, collision avoidance, and substitution control other than electric power steering control is difficult. When the value exceeds the limit value, there is a problem that necessary vehicle behavior control cannot be performed.

  The present invention has been made to solve the above-described problems. Even when the amount of current to the assist motor is limited in order to prevent overheating of the assist motor and its drive circuit, It is an object of the present invention to provide a vehicle steering control device capable of appropriately executing vehicle behavior control based on a control request from a control device.

  A vehicle steering control device according to the present invention controls driving of an electric power steering device having a steering mechanism and an assist motor for applying a steering assist force to the steering mechanism, and cooperates with other control devices of the vehicle. A motor current determination unit that controls the behavior of the vehicle, determines a drive current to be passed to the assist motor in accordance with an external command, and monitors the steering torque and the vehicle speed applied to the steering mechanism by the driver. Based on the values of the torque and the vehicle speed, the basic assist torque for generating the steering assist force in the assist motor is calculated, and the basic assist command value that is an output command of the amount of current required to execute the basic assist torque is calculated. The basic assist command value calculation unit sent to the motor current determination unit and the drive status of the assist motor drive system are monitored and A control request from a current limit execution unit that sends a current limit command to the motor current determination unit to impose a limit on the amount of drive current from the motor current determination unit to the assist motor according to the driving situation, and other control devices A correction torque command value calculation unit that calculates a correction torque that is a driving torque of the assist motor for responding to the motor and sends a correction torque command value that is an output command of an amount of current required to execute the correction torque to the motor current determination unit. The correction torque command value calculation unit assists the motor current determination unit with the current of the corrected torque command value exceeding the current limit when the current limit is imposed on the motor current determination unit by the current limit execution unit. In order to output to the motor, a current limit change command is sent to the motor current determination unit together with the correction torque command value.

  According to the vehicle steering control device of the present invention, the correction torque command value calculation unit, when the current limit is imposed on the motor current determination unit by the current limit execution unit, the correction torque command exceeding the current limit amount. Since the current limit change command for causing the motor current determination unit to output the current of the value to the assist motor is sent to the motor current determination unit together with the correction torque command value, the motor current determination unit sets the current imposed by the current limit execution unit. Even if the amount of current to the assist motor is limited in order to prevent overheating of the assist motor and its drive circuit by changing the limit and making the correction torque command value executable, other control devices The vehicle behavior control based on the control request from can be appropriately executed.

The best mode for carrying out the present invention will be described below with reference to the drawings.
Embodiment 1 FIG.
1 is a block diagram showing an integrated control device including a vehicle steering control device according to Embodiment 1 of the present invention.
In FIG. 1, an integrated control device 1 includes an engine control ECU (Electronic Control Unit) 2, a skid prevention control ECU 3, an electric power steering control ECU 4 as a vehicle steering control device, a transmission control ECU 5, A driving force distribution control ECU 6 and a suspension control ECU 7 are provided. These ECUs 2 to 7 can communicate with each other via the network bus 8.

  The engine control ECU 2 controls combustion of an engine (not shown). The skid prevention control ECU 3 controls the operation of a brake device (not shown). Further, the side slip prevention control ECU 3 monitors signals such as a steering wheel angle signal and a yaw rate signal (both not shown). Further, the side slip prevention control ECU 3 detects the occurrence of a side slip of the vehicle based on signals such as a steering wheel angle signal and a yaw rate signal.

  The electric power steering control ECU 4 controls driving of the electric power steering device. The transmission control ECU 5 controls driving of a transmission mechanism (not shown). The driving force distribution control ECU 6 controls the distribution ratio of the driving force between the front wheels and the rear wheels. The suspension control ECU 7 controls the load balance applied to the four wheels of the vehicle.

  Here, the function of the integrated control apparatus 1 will be described by taking as an example a case where the vehicle is in an oversteer state due to excessive speed at the time of a lane change. In such a case, the skid prevention control ECU 3 first determines that the vehicle is in an oversteer state based on signals such as a steering wheel angle signal and a yaw rate signal. Then, the skid prevention control ECU 3 sends control requests to the other ECUs 2 and 4 to 7 almost simultaneously.

  Specifically, the skid prevention control ECU 3 sends a drive signal to a brake device (not shown) to brake the wheels on the outside of the curve and suppress the rotational moment of the vehicle. Further, the skid prevention control ECU 3 sends an engine output reduction request to the engine control ECU 2 in order to reduce the vehicle speed. Further, the skid prevention control ECU 3 sends a control request to the electric power steering control ECU 4 so as to assist the steering in a direction to cancel the rotational moment of the vehicle.

  Further, the skid prevention control ECU 3 sends a control request to the transmission control ECU 5 to shift down and apply the engine brake in order to effectively use the deceleration torque generated by the output reduction of the engine control ECU 2. Furthermore, the side slip prevention control ECU 3 prevents the rear wheels from slipping by distributing a large amount of driving force to the front wheel side to the driving force distribution control ECU 6. Further, the side slip prevention control ECU 3 sends a control request to the suspension control ECU 7 so as to optimize the load on the four wheels in order to suppress the occurrence of rolling of the vehicle due to turning. Here, the control requests from the side slip prevention control ECU 3 are generated in appropriate combination according to the state of the vehicle.

  Next, another example regarding vehicle behavior control will be described. When the driving force distribution control ECU 6 detects that the roll of the vehicle is relatively strong while the vehicle is running on a curve, the steering assist is applied to the electric power steering control ECU 4 in a direction in which the roll applied to the vehicle decreases. Send a control request to At the same time, the driving force distribution control ECU 6 sends a control request to the skid prevention control ECU 3 to brake a specific wheel.

  FIG. 2 is a configuration diagram showing the electric power steering apparatus 100 controlled by the electric power steering control ECU 4 of FIG. In FIG. 2, an electric power steering apparatus 100 includes a steering mechanism 101, an assist motor (electric motor) 102, a motor driver 103, and a power supply apparatus (not shown). The steering mechanism 101 includes a handle 111, a steering shaft 112, a motor gear 113, a rack and pinion mechanism 114, and a pair of tires 115A and 115B.

  The steering wheel 111 is a steering wheel of an automobile that is steered (operated) by a driver. A steering torque from the driver is applied to the steering shaft 112 via the handle 111. A torque sensor 121 is attached to the steering shaft 112. The torque sensor 121 generates a steering torque signal corresponding to the steering torque. The steering torque signal generated by the torque sensor 121 is sent to the electric power steering control ECU 4.

  The assist motor 102 is coupled to the steering shaft 112 via a motor gear 113. Further, the assist motor 102 applies assist torque (steering assist force) for assisting the steering torque to the steering shaft 112. A combined torque obtained by adding the steering torque and the assist torque applied to the steering shaft 112 is transmitted to the rack and pinion mechanism 114. And the rudder angle of a pair of tire 115A, 115B is operated by this synthetic torque.

  In addition to the torque sensor 121, a vehicle speed sensor 122, a temperature sensor 123, a voltage sensor 124, a current sensor 125, and a rotation angle sensor 126 are connected to the electric power steering control ECU 4. The vehicle speed sensor 122 is rotation detection means such as a rotary encoder, for example, and generates a signal corresponding to the vehicle speed. The temperature sensor 123 generates a signal corresponding to the temperature of the motor.

  The voltage sensor 124 generates a signal corresponding to the voltage applied to the coil of the assist motor 102. The current sensor 125 generates a signal corresponding to the current flowing through the coil of the assist motor 102. The rotation angle sensor 126 is, for example, a resolver and generates a signal corresponding to the rotation angle of the assist motor 102. The electric power steering control ECU 4 is connected to the network bus 8 via the communication means 127.

  Next, an outline of the electric power steering control ECU 4 will be described. FIG. 3 is a block diagram specifically showing the electric power steering control ECU 4 of FIGS. 1 and 2. 3, the electric power steering control ECU 4 includes a basic assist command value calculation unit 201, a motor current determination unit 202, a current limit execution unit 203, a control request reception unit 204, a control priority determination unit 205, and a correction torque command value calculation. Unit 206, control execution degree transmission unit 207, and adder 208.

  The basic assist command value calculation unit 201 receives a steering torque signal output from the torque sensor 121 and a vehicle speed signal output from the vehicle speed sensor 122. The basic assist command value calculation unit 201 calculates the assist torque generated by the assist motor 102 as the basic assist torque based on the steering torque and the vehicle speed. Further, the basic assist command value calculation unit 201 sends a basic assist command value, which is an output command for the amount of current required for executing the basic assist torque, to the adder 208.

  The current limit execution unit 203 is based on information such as a temperature sensor 123, a voltage sensor 124, a current sensor 125, and a rotation angle sensor 126 connected to the assist motor 102, and the assist motor 102 drive system (assist motor 102 and motor driver). 103) is monitored. The current limit execution unit 203 limits the amount of drive current to the assist motor 102 in order to prevent overheating of the assist motor 102 and the motor driver 103 in accordance with the drive status of the drive system of the assist motor 102. Determine whether to impose. At this time, the current limit execution unit 203 sends a current limit command to the motor current determination unit 202 and the control priority determination unit 205 when imposing a limit on the amount of drive current to the assist motor 102. The current limit command includes information on the amount of current to be limited, that is, the amount of limit current.

  The motor current determination unit 202 stores in advance information on the maximum output amount of current of the motor driver 103. The motor current determination unit 202 calculates the executable current amount by subtracting the current limit amount from the stored maximum output of the motor driver 103 in a state where the current limit is imposed by the current limit execution unit 203. Then, the motor current determination unit 202 determines the amount of drive current output to the assist motor 102 within the range of the executable current amount.

  The control request receiving unit 204 receives control requests from other ECUs 2, 3, 5 to 7 (that is, other control devices) via the communication unit 127. This control request includes information on the required torque. The control request receiving unit 204 sends the received control request to the control priority determining unit 205. The control priority determination unit 205 determines the control priority for the control request received from the control request reception unit 204 using a predetermined method. The predetermined method is a method in which the control priority determination unit 205 determines the control priority based on the state (current limit amount) of the drive system of the assist motor 102. In addition, the control priority determination unit 205 sends the determined control priority information, control request information, and current limit command information to the corrected torque command value calculation unit 206.

  When the correction torque command value calculation unit 206 receives the control priority information and the control request information from the control priority determination unit 205, the correction torque command value calculation unit 206 checks whether or not the current limit is being executed by the current limit execution unit 203. . At this time, if the current limit is not executed by the current limit execution unit 203, the correction torque command value calculation unit 206 directly uses the amount of current required for executing the required torque as the correction torque command value as an adder 208. Send to.

  On the other hand, when the current limit is being executed by the current limit execution unit 203 and the requested torque cannot be executed as it is, the corrected torque command value calculation unit 206 calculates the control execution degree based on the control priority. This control execution degree mediates (harmonizes) protection of the drive system of the assist motor 102 and responses to control requests from the other ECUs 2, 3, 5 to 7 during execution of current limiting by the current limiting execution unit 203. ). In addition, this control execution degree is a value of 1%-100%, for example.

  The corrected torque command value calculation unit 206 calculates the corrected torque by multiplying the required torque included in the control request by the control execution degree. Further, the correction torque command value calculation unit 206 sends the amount of current required to execute the correction torque to the adder 208 as a correction torque command value. Further, the correction torque command value calculation unit 206 determines the current of the correction torque command value exceeding the current limit amount when the current limit is imposed on the motor current determination unit 202 by the current limit execution unit 203. In order to output the assist motor 102 from the unit 202, a limit change command is sent to the motor current determination unit 202 together with the correction torque command value. This limit change command is a command for changing the current limit amount (current amount) imposed on the motor current determination unit 202.

  The control execution degree transmission unit 207 transmits the control execution degree determined by the correction torque command value calculation unit 206 to the other ECUs 2, 3, 5 to 7 via the communication unit 127 and the network bus 8. As a result, the other ECUs 2, 3, 5 to 7 execute alternative control so as to supplement the control amount that cannot be executed by the electric power steering apparatus 100.

  Here, as an example of alternative control by the other ECUs 2, 3, 5 to 7, the skid prevention control ECU 3 brakes a specific wheel, or the driving force distribution control ECU 6 drives the driving force between the front wheels and the rear wheels. And the suspension control ECU 7 changes the load balance of the vehicle.

  Adder 208 adds the basic assist command value and the corrected torque command value, and sends the total value to motor current determination unit 202. The motor current determination unit 202 determines the current amount of the drive current of the assist motor 102 based on the basic assist command value and the correction torque command value, and supplies the drive current to the assist motor 102 via the motor driver 103. Shed.

  Next, the control priority determination processing by the control priority determination unit 205 will be specifically described. FIG. 4 is a control priority determination map (graph) for explaining the control priority determination processing by the control priority determination unit 205 of FIG. A control priority determination map as shown in FIG. 4 is preset in the control priority determination unit 205. As shown in FIG. 4, the control priority determination map has a characteristic that the control priority decreases in proportion to the current limit amount. Specifically, when the current limit amount is 0, the control priority is the highest. On the other hand, when the current limit amount is the maximum, the control priority is the lowest.

  Here, the current limit amount of the electric power steering device 100 increases when the temperature of the assist motor 102 is relatively high or when the energization time of the assist motor 102 is relatively long. A large current limit amount indicates that the load on the electric power steering apparatus 100 is so large that the possibility of responding to a control request is low.

  Next, the determination process of the control execution degree by the correction torque command value calculation unit 206 will be described. FIG. 5 is a control execution degree determination map (graph) for explaining the control execution degree determination process by the correction torque command value calculation unit 206 of FIG. In the corrected torque command value calculation unit 206, a control priority determination map is set in advance. In this control priority determination map, when the control priority is the lowest, an offset is set so that the control execution degree is 50%. Further, the control execution degree is set to increase in proportion to the control priority. When the control priority is the highest, the control priority is 100%.

Specifically, the corrected torque command value calculation unit 206 refers to the control execution degree determination map shown in FIG. 5 on the basis of the control priority determined by the control priority determination unit 205, so that the control execution degree (% ) Is calculated. Then, the correction torque command value calculation unit 206 calculates the correction torque that is actually executed out of the required torque included in the control request by calculating the following equation (1).
Correction torque = Required torque x Control execution rate (%) ··· (1) equation

  Here, when the current limit is imposed, the motor current determination unit 202 has a total value (converted value of the current amount) of the basic assist command value and the corrected torque command value within the executable current amount. The drive current of the amount of current required to execute the basic assist command value and the correction torque command value is passed through the assist motor 102 as it is.

  On the other hand, if the sum of the basic assist command value and the correction torque command value exceeds the executable current amount due to the relatively large current limit amount, the amount of current flowing from the motor current determining unit 202 to the assist motor 102 is limited. The response to the control request is not sufficiently executed. Here, the process of the motor current determination unit 202 in a situation where the total value of the basic assist command value and the correction torque command value exceeds the executable current amount will be described.

  FIG. 6 is an explanatory diagram for explaining the current limit amount changing process by the motor current determination unit 202 of FIG. 3. In FIG. 6, a current limit map (broken line in FIG. 6) according to the temperature rise of the assist motor 102 is provided to the motor current determination unit 202 in order to protect the assist motor 102 and the motor driver 103 from overheating by the current limit execution unit 203. Suppose you are given.

  In this case, if the current temperature rise of the assist motor 102 is at point A, the current limiting amount at this time is point B. In this state, the motor current determination unit 202 determines the amount of current that flows through the assist motor 103 within the range of the executable current amount X. However, when the total value of the basic assist command value and the correction torque command value exceeds the executable current amount X, the correction torque command is not sufficiently executed.

Therefore, when motor current determination unit 202 receives a limit change command from correction torque command value calculation unit 206, motor current determination unit 202 reduces the current limit amount based on the limit change command. Specifically, when the basic assist command value is near the point B (current amount substantially equal to the executable current amount X), the correction torque output by the correction torque command value calculation unit 206 is reliably executed. The execution current limit amount (point C) is calculated by the motor current determination unit 202 calculating the following equation (2).
Execution current limit amount (C point) = current limit amount (B point)-correction torque (current conversion value)
... (2) formula

  As described above, the motor current determination unit 202 flexibly changes the current limit amount in accordance with the limit change command from the correction torque command value calculation unit 206. Thereby, the motor current determination unit 202 changes the executable current amount from the executable current amount X to the executable current amount Y. Therefore, even if a limit is imposed on the amount of current from the motor current determining unit 202 to the assist motor 102, the necessary correction torque is reliably executed.

  Here, the electric power steering control ECU 4 can be configured by a computer (not shown) having an arithmetic processing unit (CPU), a storage unit (ROM, RAM, hard disk, etc.) and a signal input / output unit. A computer storage unit of the electric power steering control ECU 4 includes a basic assist command value calculation unit 201, a motor current determination unit 202, a current limit execution unit 203, a control request reception unit 204, a control priority determination unit 205, a correction torque command. A program for realizing the functions of the value calculation unit 206, the control execution degree transmission unit 207, and the adder 208 is stored.

  Also, the other ECUs 2, 3, 5 to 7 (other control devices) can be configured by a computer (not shown) as in the case of the electric power steering control ECU 4. Programs for realizing the respective functions are stored in the storage units of the computers of these ECUs 2, 3, 5-7.

  Next, the operation when the electric power steering control ECU 4 receives a control request from the other ECUs 2, 3, 5 to 7 will be described. FIG. 7 is a flowchart showing the operation of the electric power steering control ECU 4 of FIG. In FIG. 7, the electric power steering control ECU 4 first reads the steering torque and the vehicle speed via the torque sensor 121 and the vehicle speed sensor 122 (step S101). Thereafter, the electric power steering control ECU 4 calculates a basic assist torque as a reference for steering assistance (step S102).

  Then, the electric power steering control ECU 4 reads the temperature, current, voltage, and rotation speed of the assist motor 102 via the various sensors 123 to 126 (step S103). Thereafter, the electric power steering control ECU 4 determines whether or not current limitation is necessary based on the read driving conditions of the driving system of the assist motor 102 such as the temperature, current, voltage, and rotation speed of the motor (step). S104).

  At this time, if it is determined that the current limit is necessary, the electric power steering control ECU 4 executes the current limit (step S105). On the other hand, when it is determined that the current limit is unnecessary, the electric power steering control ECU 4 does not execute the current limit. In this state, when the electric power steering control ECU 4 receives a control request from the other ECUs 2, 3, 5 to 7 (step S106), it determines the control priority for the control request (step S107).

  Then, the electric power steering control ECU 4 calculates a control execution degree based on the determined control priority (step S108). When the control execution degree is calculated, the electric power steering control ECU 4 calculates the correction torque by multiplying the required torque by the control execution degree (step S109).

  Further, the electric power steering control ECU 4 checks whether or not a current limit change is necessary (step S110). At this time, if the electric power steering control ECU 4 determines that the current limit change is necessary, the electric power steering control ECU 4 changes the current limit (step S111), and the current amount corresponding to the basic assist torque and the correction torque is changed. The drive current is output to the assist motor 103 (step S112).

  On the other hand, if the electric power steering control ECU 4 determines that the current limit change is not necessary, the electric power steering control ECU 4 outputs the current amount corresponding to the basic assist torque and the correction torque to the assist motor 103 as it is (step S112). Then, the electric power steering control ECU 4 repeats the same operation.

  In the vehicle steering control device as described above, when the current limit is imposed on the motor current determination unit 202 by the current limit execution unit 203, the correction torque command value calculation unit 206 outputs the current limit change command and the correction torque command. The value is sent to the motor current determination unit 202 together with the value. With this configuration, the motor current determination unit 202 can change the current limit imposed by the current limit execution unit 203 and execute the corrected torque command value. Thus, even when the amount of current to the assist motor is limited in order to prevent overheating of the drive system of the assist motor 102, behavior control of the vehicle based on control requests from the other ECUs 2, 3, 5-7. Can be executed appropriately.

  Further, the corrected torque command value calculation unit 206 calculates the control execution degree based on the control priority received from the control priority determination unit 205, and the control execution degree is calculated from the other ECUs 2, 3, 5 to 7. A correction torque is calculated by multiplying the required torque included in the control request. With this configuration, it is possible to appropriately mediate protection of the drive system of the assist motor 102 and responses to control requests from the other ECUs 2, 3, 5-7.

  Further, the control execution degree transmission unit 207 transmits the control execution degree determined by the correction torque command value calculation unit 206 to the other ECUs 2, 3, 5 to 7. With this configuration, the required torque executed by the electric power steering device 100 is fed back to the other ECUs 2, 3, 5-7. When it is determined that the other ECUs 2, 3, 5 to 7 are insufficient with respect to the execution amount by the electric power steering device 100, the alternative control is executed by the ECUs 2, 3, 5-7. Optimum vehicle behavior control becomes possible. In addition, since the vehicle responds as the driver intends, a situation in which the driver becomes anxious can be prevented.

  In the control execution degree determination map of FIG. 5 in the first embodiment, the offset value is set to 50%. However, the offset value may be a value exceeding 0%, and can be determined as appropriate.

  In the first embodiment, the motor current determination unit 202 changes the current limit amount based on the current limit command of the current limit execution unit 203 in accordance with the current limit change command from the correction torque command value calculation unit 206. The amount of current that can be implemented was increased. However, the present invention is not limited to this example. When the motor current determination unit 202 receives the current limit change command from the correction torque command value calculation unit 206, the current limit by the current limit execution unit 203 is (temporarily) canceled. May be.

Embodiment 2. FIG.
In the first embodiment, the control priority determination unit 205 determines the control priority using a control priority determination map as shown in FIG. On the other hand, in the second embodiment, the control priority determination unit 205 determines the control priority based on the priority identification information included in the control request. In the second embodiment, the other ECUs 2, 3, 5 to 7 determine the control priority for the electric power steering apparatus 100.

  FIG. 8 is an explanatory diagram for explaining a message format of a control request transmitted from another ECU 2, 3, 5 to 7 according to the second embodiment of the present invention. The control priority determination unit 205 according to the second embodiment determines the control priority based on the message format shown in FIG. Specifically, in FIG. 8A, 2 bits of 0 to 1 bits in the message format of the control request are the priority identification information and indicate the control priority. As shown in FIG. 8B, 0 to 1 bit “00” is a control priority “low”, 0 to 1 bit “01” is a control priority “medium”, and 0 to 1 bit “0”. “10” represents the control priority “high”.

  Further, the control priority determination unit 205 of the second embodiment reads the request torque included in the control request by reading 6 bits of 2 to 7 bits in the message format of the control request shown in FIG. get. Here, as shown in FIG. 8C, the required torque is, for example, a dynamic range of −3 Nm to 3 Nm and a resolution of 0.094 Nm.

  Next, in the correction torque command value calculation unit 206 according to the second embodiment, for example, a correspondence table between control execution degrees and control priorities as illustrated in FIG. 9 is registered in advance. The corrected torque command value calculation unit 206 determines the control execution level by referring to the correspondence table as shown in FIG. 9 based on the control priority received from the control priority determination unit 205. Then, similarly to the first embodiment, the correction torque command value calculation unit 206 calculates the correction torque by multiplying the required torque by the control execution degree, and determines the correction torque command value.

  Therefore, the predetermined method in the second embodiment is a method in which the control priority determination unit 205 determines the control priority based on the priority identification information included in the control request. Other configurations and operations are the same as those in the first embodiment.

  In the vehicle steering control device as described above, even when the amount of current flowing to the assist motor 102 is limited in order to prevent overheating of the drive system of the assist motor 102, the other ECUs 2, 3, 5 to 7 are used. Based on the control priority corresponding to the degree of urgency determined by (1), appropriate assist control exceeding the current limit amount becomes possible. For this reason, for example, when vehicle behavior control with high urgency such as avoiding a collision is required, the electric power steering device 100 does not stop responding because the current is limited, and the vehicle behavior control is executed more reliably. Can do. That is, it is possible to realize vehicle behavior control in accordance with the degree of urgency.

  Further, since the control priority determined by the other ECUs 2, 3, 5 to 7 is used, the other ECUs 2, 3, 3 are independent of the state of the electric power steering device 100 (particularly, the drive system of the assist motor 102). 5 to 7 can cause the electric power steering apparatus 100 to execute the required torque.

Embodiment 3 FIG.
In the first embodiment, the control priority determination unit 205 determines the control priority using a control priority determination map as shown in FIG. On the other hand, in the third embodiment, the control priority determination unit 205 determines the control priority based on the magnitude of the required torque included in the control requests from the other ECUs 2, 3, 5-7.

  FIG. 10 is a control priority determination map (graph) used for control priority determination processing by the vehicle steering control apparatus according to Embodiment 3 of the present invention. A control priority determination map as shown in FIG. 10 is registered in advance in the control priority determination unit 205 of the third embodiment. Moreover, the control priority determination part 205 acquires the request torque of the control request from other ECU2,3,5-7, and refers to a map as shown in FIG. 10 based on the acquired request torque. The control priority is determined.

  Here, the smaller the required torque of the control request from the other ECUs 2, 3, 5 to 7, the higher the possibility that the total value of the assist torque and the correction torque does not exceed the current limit amount. For this reason, the smaller the required torque, the higher the control priority, and the higher the control execution degree, it is possible to respond to the control request from the other ECUs 2, 3, 5-7 to the maximum. Become.

  Therefore, the predetermined method in the third embodiment is that the control priority determination unit 205 controls the control priority based on the magnitude of the requested torque included in the control requests received from the other ECUs 2, 3, 5-7. This is a method for determining. Other configurations and operations are the same as those in the first embodiment.

  In the vehicle steering control device as described above, the control priority determination unit 205 determines the control priority based on the magnitude of the requested torque of the control request. With this configuration, the other ECUs 2, 3, 5 to 7 can execute the behavior control of the vehicle in an optimum state without considering the control priority in the electric power steering control ECU 4. In other words, the other ECUs 2, 3, 5 to 7 can determine the control amount of the assist motor 102 independently of the internal processing of the electric power steering control ECU 4.

  Note that the setting of the control priority determination map shown in FIG. 10 of the third embodiment is merely an example, and contrary to the example shown in FIG. 10, the requested torque of the control request from the other ECUs 2, 3, 5 to 7. The control priority may be increased as the value of is larger.

Embodiment 4 FIG.
In the first embodiment, the control priority determination unit 205 determines the control priority using a control priority determination map as shown in FIG. On the other hand, in the fifth embodiment, the control priority determination unit 205 determines the control priority based on the number of times control requests are received from the other ECUs 2, 3, 5-7.

  FIG. 11 is a block diagram showing a part of a vehicle steering control apparatus according to Embodiment 4 of the present invention. The control priority determination unit 205 includes a control request counting unit (counter unit) 205a and a control priority calculation unit 205b. The control request counting unit 205a counts the number of control requests received by the control request receiving unit. A control priority determination map as shown in FIG. 12 is preset in the control priority calculation means 205b. The control priority calculating unit 205b determines (calculates) the control priority by referring to a control priority determination map as shown in FIG. 12 based on the count value of the control request by the control request counting unit 205a.

  Therefore, the predetermined method in the fourth embodiment is that the control priority determination unit 205 counts the number of control requests received from the other ECUs 2, 3, 5 to 7, and the control priority is based on the counted value. This is a method for determining the degree. Other configurations and operations are the same as those in the first embodiment.

  In the vehicle steering control apparatus as described above, the control priority is determined according to the number of control requests. With this configuration, the control request is repeatedly sent to the electric power steering control ECU 4 until a necessary response is obtained without the other ECUs 2, 3, 5 to 7 calculating specific control priority values. The integrated control of the vehicle can be executed in an optimum state.

  The electric power steering control ECU 4 calculates a control execution degree or a correction torque every time a control request is received from the other ECUs 2, 3, 5 to 7, and uses the information on the control execution degree or the correction torque as another ECU 2 , 3, 5 to 7 (the ECU that sent the control request). In this case, the other ECUs 2, 3, 5 to 7 repeatedly send control requests to the electric power steering control ECU 4 until a desired (minimum level) correction torque is calculated by the electric power steering control ECU 4. Become.

  In addition, the number of control request transmissions of the control request transmission source ECUs 2, 3, 5 to 7 may be set in advance. In this case, for example, a control priority map as shown in FIG. 12 is registered in advance in the ECUs 2, 3, 5 to 7 that transmit the control request, and the correction torque to be executed by the electric power steering apparatus 100 becomes a desired value. In this way, the ECUs 2, 3, 5 to 7 are configured to repeatedly send control requests to the electric power steering control ECU 4.

Embodiment 5 FIG.
In the first embodiment, the control execution degree transmission unit 207 transmits information on the control execution degree determined by the correction torque command value calculation unit 206 to the other ECUs 2, 3, 5-7. On the other hand, in the fifth embodiment, the control execution degree transmission unit 207 sends information on the alternative control degree to the other ECUs 2, 3, 5-7 in addition to the information on the control execution degree.

  FIG. 13 is a control degree determination map (graph) for explaining the control amount arbitration process of the control execution degree transmission unit 207 according to the fifth embodiment of the present invention. The control execution degree transmission unit 207 according to the fifth embodiment includes control amount arbitration means (not shown). The control amount arbitration means of the control execution degree transmission unit 207 is calculated by the correction torque command value calculation unit 206 when the correction torque is smaller than the request torque included in the control request received from the other ECUs 2, 3, 5-7. Based on the executed control execution degree, the control degree of the alternative control of the other ECUs 2, 3, 5 to 7 is calculated by referring to a control degree determination map as shown in FIG.

  Specifically, when the control execution degree is small, the control by the electric power steering apparatus 100 is insufficient, so the control degree of the alternative control by the other ECUs 2, 3, 5 to 7 is set to be stronger. On the other hand, if the control execution degree is 100%, the substitution control by the other ECUs 2, 3, 5-7 becomes unnecessary, and the control degree of the substitution control by the other ECUs 2, 3, 5-7 is A normal control amount calculated in advance may be used. For this reason, the control degree by the other ECUs 2, 3, 5 to 7 is set to normal. Other configurations and operations are the same as those in any of the first to fourth embodiments.

  In the vehicle steering control apparatus as described above, when the electric power steering apparatus 100 cannot execute all the control requests from the other ECUs 2, 3, 5 to 7, the control amount arbitration means of the control execution degree transmission unit 207 is The control degree of the alternative control by the other ECUs 2, 3, 5 to 7 is determined. Then, the control execution degree transmitting unit 207 transmits the control execution degree information and the control degree information to the other ECUs 2, 3, 5 to 7. With this configuration, other ECUs 2, 3, 5 to 7 can perform alternative control of the amount that cannot be executed by the electric power steering apparatus 100 based on the control degree information, and more optimal vehicle behavior control can be executed. it can.

  In the first to fifth embodiments, the current limit execution unit 203 monitors the drive system of the assist motor 102 using the temperature sensor 123, the voltage sensor 124, the current sensor 125, and the rotation angle sensor 126. However, for these sensors 123 to 126, some sensors may be omitted and only necessary sensors may be used.

  Moreover, in Embodiment 1-5, the integrated control apparatus 1 had several ECU2-7, and these ECU2-7 was the structure which controls the behavior of a vehicle in cooperation with each other. However, the configuration of the integrated control device 1 is not limited to this example, and the integrated control device 1 may further include an overall control ECU. In this case, the overall control ECU can control the plurality of ECUs 2 to 7 and send a command to each of the plurality of ECUs 2 to 7 individually.

  Further, in the first to fifth embodiments, a plurality of ECUs 2 to 7 are connected to each other via the network bus 8, but the network bus 8 is omitted and necessary ECUs are connected to each other. It may be configured. Further, a configuration may be adopted in which a central control ECU that controls the plurality of ECUs 2 to 8 is provided in the integrated control apparatus 1 and the plurality of ECUs 2 to 8 are individually connected to the control ECU.

It is a block diagram which shows the integrated control apparatus containing the steering control apparatus for vehicles by Embodiment 1 of this invention. It is a block diagram which shows the electric power steering apparatus controlled by ECU for electric power steering control of FIG. FIG. 3 is a block diagram specifically showing an electric power steering control ECU of FIGS. 1 and 2. 4 is a control priority determination map for explaining a control priority determination process by a control priority determination unit in FIG. 3. FIG. 4 is a control execution degree determination map for explaining a control execution degree determination process by a correction torque command value calculation unit of FIG. 3. FIG. It is explanatory drawing for demonstrating the change process of the execution current limiting amount by the motor current determination part of FIG. 3 is a flowchart showing an operation of the electric power steering control ECU of FIG. 1. It is explanatory drawing for demonstrating the message format of the control request transmitted from other ECU by Embodiment 2 of this invention. It is explanatory drawing for demonstrating the correspondence of the control execution degree of FIG. 8, and control priority. It is a control priority determination map used for the determination process of the control priority by the vehicle steering control apparatus of Embodiment 3 of this invention. It is a block diagram which shows a part of vehicle steering control apparatus by Embodiment 4 of this invention. FIG. 12 is a control priority determination map for explaining control priority determination processing by the control priority calculation means of FIG. 11. FIG. It is a control degree determination map for demonstrating the control amount arbitration process of the control execution degree transmission part by Embodiment 5 of this invention.

Explanation of symbols

  2 ECU for engine control (other control device), 3 ECU for prevention control (other control device), 4 ECU for electric power steering control (steering control device for vehicle), 5 ECU for transmission control (other control device) , 6 Driving force distribution control ECU (other control device), 7 Suspension control ECU (other control device), 100 Electric power steering device, 101 Steering mechanism, 102 Assist motor 102 Motor driver, 201 Basic assist command value calculation Unit, 202 motor current determination unit, 203 current limit execution unit, 204 control request reception unit, 205 control priority determination unit, 206 correction torque command value calculation unit, 207 control execution level transmission unit.

Claims (8)

Vehicle steering for controlling the drive of an electric power steering device having a steering mechanism and an assist motor for applying a steering assist force to the steering mechanism, and controlling the behavior of the vehicle in cooperation with other control devices of the vehicle A control device,
A motor current determination unit for determining a drive current to flow to the assist motor in accordance with an external command;
The driver monitors the steering torque and the vehicle speed applied to the steering mechanism, and calculates a basic assist torque for causing the assist motor to generate a steering assist force based on the values of the steering torque and the vehicle speed. A basic assist command value calculation unit that sends a basic assist command value that is an output command of an amount of current required to execute the basic assist torque to the motor current determination unit,
The driving status of the assist motor drive system is monitored, and a motor current determination command is provided for imposing a current limiting command on the driving current from the motor current determining unit to the assist motor in accordance with the driving status. A correction torque, which is a driving torque of the assist motor for responding to a control request from the other control device, and an output command of an amount of current required to execute the correction torque. A correction torque command value calculation unit that sends a correction torque command value to the motor current determination unit,
The correction torque command value calculation unit determines a current of the correction torque command value that exceeds a current limit amount when the current limit is imposed on the motor current determination unit by the current limit execution unit. A vehicle steering control device, wherein a current limit change command is sent to the motor current determination unit together with the correction torque command value in order to cause the assist motor to output from the unit. A control priority determination unit that determines a control priority for a control request received from the other control device by a predetermined method;
The correction torque command value calculation unit calculates a control execution degree based on the control priority received from the control priority determination unit, and the control execution degree is included in the control request received from the other control device. The vehicle steering control device according to claim 1, wherein the correction torque is calculated by multiplying the required torque. The vehicle steering control device according to claim 2, wherein the control priority determination unit determines the control priority based on a driving situation of a drive system of the assist motor as the predetermined method. The control priority determination unit determines the control priority based on priority identification information included in a control request received from the other control device as the predetermined method. The vehicle steering control device. The said control priority determination part determines the said control priority as a said predetermined system based on the magnitude | size of the request | requirement torque contained in the control request received from the said other control apparatus. The vehicle steering control device described. The vehicle steering control according to claim 2, wherein the control priority determination unit determines the control priority based on the number of control requests received from the other control device as the predetermined method. apparatus. The control execution degree transmission part which transmits the information of the said control execution degree calculated by the said correction | amendment torque command value calculation part to said other control apparatus further, The any of Claim 2 to 6 characterized by the above-mentioned. The vehicle steering control device according to claim 1. When the correction torque is smaller than the request torque included in the control request received from the other control device, the control execution degree transmission unit determines the control degree for the alternative control by the other control device, The vehicle steering control device according to claim 7, wherein the control degree information is transmitted to the other control device together with the control execution degree information.

Images