WO2021014769A1 - Control device and control method for vehicle - Google Patents

Abstract

A control device (100) controls traveling of a vehicle (10) which travels by means of a driving force of an electric motor (20). The control device (100) is provided with: a vehicle control unit (110) that determines target torque Tt to be generated by the electric motor in accordance with an accelerator operation carried out by a driver, and outputs a control signal for an instruction of driving of the electric motor at the target torque; and a monitoring unit (120) that determines monitoring torque Ttw in accordance with the accelerator operation, and instructs execution of a fail-safe process on the electric motor when determination conditions, including a condition that the target torque and the monitoring torque do not match each other in terms of being positive/negative, are satisfied.

Description

Vehicle control device and control method Cross-reference of related applications

The present application claims priority based on the Japanese patent application of application number 2019-136926 filed on July 25, 2019, all of which are incorporated herein by reference.

The present disclosure relates to a technology for controlling the running of a vehicle traveling by an electric motor.

Conventionally, in vehicles, a technique for executing a fail-safe process that controls the safety side when an abnormality in an electronic device including an electric motor is detected has been known. For example, Japanese Patent Application Laid-Open No. 2016-147585 provides a fail-safe process that monitors the occurrence of an abnormality in a microcomputer that controls a vehicle actuator by self-diagnosis and shifts the actuator to a safe state when an abnormality is detected. The technology to be implemented is disclosed.

Some vehicles traveling by electric motor perform fail-safe processing when an abnormality in the control signal of the electric motor is detected during acceleration or deceleration of the vehicle in order to suppress the occurrence of malfunction of the electric motor. In order to improve the reliability of the control of the electric motor, further improvement is required for detecting the abnormality of the control signal of the electric motor and taking appropriate measures.

The present disclosure can be realized, for example, in the following form.

One form of the present disclosure is provided as a control device that controls the running of a traveling vehicle by the driving force of an electric motor. The control device of this form determines a target torque to be generated in the electric motor according to the accelerator opening degree, and outputs a control signal for instructing the driving of the electric motor at the target torque, and the accelerator opening. A monitoring unit that determines the monitoring torque according to the degree and commands the execution of fail-safe processing of the electric motor when the determination conditions including the condition that the positive and negative of the target torque and the monitoring torque do not match are satisfied. , Equipped with.

According to this type of control device, by determining whether the positive or negative of the target torque and the monitoring torque are reversed, it is possible to easily detect the occurrence of an abnormality in the control signal that leads to erroneous control of the rotation direction of the motor. It is possible to take appropriate measures against the abnormality. Therefore, the reliability of the control of the electric motor can be improved.

The above objectives and other objectives, features and advantages of the present disclosure will be clarified by the following detailed description with reference to the accompanying drawings. The drawing is
FIG. 1 is a schematic view showing the configuration of a vehicle equipped with a control device. FIG. 2 is a schematic block diagram showing the functional configuration of the control device. FIG. 3 is a schematic block diagram showing the functional configuration of the vehicle control unit. FIG. 4 is a schematic block diagram showing the functional configuration of the monitoring unit. FIG. 5 is an explanatory diagram showing a flow of control processing executed by the control device. FIG. 6 is an explanatory diagram showing a flow of the target torque determination process. FIG. 7 is an explanatory diagram showing an example of the required torque map. FIG. 8 is an explanatory diagram showing a flow of monitoring torque determination processing. FIG. 9 is an explanatory diagram showing an example of the monitoring torque map. FIG. 10 is an explanatory diagram showing a flow of acceleration control monitoring processing. FIG. 11 is an explanatory diagram showing an example of the upper limit threshold map. FIG. 12 is an explanatory diagram showing an example of the detection time map. FIG. 13 is an explanatory diagram showing a flow of deceleration control monitoring processing. FIG. 14 is an explanatory diagram showing an example of the lower limit threshold map. FIG. 15 is an explanatory diagram showing a flow of the code inversion monitoring process of the first embodiment. FIG. 16 is an explanatory diagram showing a flow of code reversal monitoring processing of the second embodiment.

1. 1. First Embodiment:
See FIG. The control device 100 in the first embodiment is mounted on the vehicle 10 and used. The control device 100 includes a vehicle control unit 110 that controls the running of the vehicle 10 and a monitoring unit 120 that monitors the control signal of the vehicle control unit 110. Details of the vehicle control unit 110 and the monitoring unit 120 will be described later. In another embodiment, the control device 100 may include at least a part of the functions of the electric motor control unit 21 described later.

The vehicle 10 includes an electric motor 20 and travels by transmitting the driving force generated by the electric motor 20 to the wheels 11. In the first embodiment, the motor generator 20 is a motor generator that also functions as a generator, and is composed of, for example, a three-phase AC motor. In the first embodiment, the vehicle 10 is configured as an electric vehicle that travels only by the driving force of the electric motor 20. The vehicle 10 is not limited to the electric vehicle. In another embodiment, the vehicle 10 may be composed of a hybrid vehicle or a plug-in hybrid vehicle including an internal combustion engine that generates a driving force together with the electric motor 20, and includes an electric motor that does not have a function as a generator. It may be composed of automobiles.

The vehicle 10 further includes an electric motor control unit 21, an accelerator opening sensor 31, a vehicle speed sensor 32, a shift position sensor 33, and a traveling mode switch 34. The electric motor control unit 21 includes an inverter (not shown) and controls the drive of the electric motor 20 under the control of the control device 100. In the first embodiment, the electric motor control unit 21 also has a function of controlling power generation by the electric motor 20.

The electric motor control unit 21 generates torque in the electric motor 20 according to the target torque Tt described later set by the control device 100. When the target torque Tt is positive, the electric motor control unit 21 causes the electric motor 20 to output the torque due to the forward rotation of the vehicle 10 in a magnitude corresponding to the absolute value of the target torque Tt. Further, when the target torque Tt is negative, the electric motor control unit 21 causes the electric motor 20 to output the torque due to the rotation of the vehicle 10 in the negative direction in a magnitude corresponding to the absolute value of the target torque Tt.

In the first embodiment, the electric motor control unit 21 causes the electric motor 20 to output a torque that causes the vehicle 10 to creep when the target torque Tt is 0 [Nm]. This torque is small enough to be canceled by the parking brake or the driver's braking operation. Hereinafter, this torque may also be referred to as "creep torque".

The accelerator opening sensor 31 detects the operation of the accelerator pedal by the driver. In the present specification, the operation of the accelerator pedal is also simply referred to as "accelerator operation". The accelerator opening sensor 31 is a sensor that detects the amount of depression of the accelerator pedal, detects the amount of depression of the accelerator pedal, and outputs a signal indicating the detection result to the control device 100 as the accelerator opening Acc. In the following description, "accelerator off" means a state in which the accelerator pedal is not depressed and the accelerator opening degree Acc = 0 degrees, and "accelerator on" means that the accelerator pedal is depressed and the accelerator opening degree Acc>. It means a state of 0 degrees.

The accelerator opening degree Acc output from the accelerator opening degree sensor 31 corresponds to an acceleration command for the vehicle 10 that controls the acceleration of the vehicle 10. The accelerator opening degree Acc as an acceleration command does not have to be output from the accelerator opening degree sensor 31. The accelerator opening degree Acc may be output to the control device 100 in order to control the running of the vehicle 10, for example, by a program for realizing the automatic driving function and the driving support function of the vehicle 10.

The vehicle speed sensor 32 is a sensor used for detecting the vehicle speed V, which is the speed of the vehicle 10, and outputs a signal indicating the detection result to the control device 100. In the first embodiment, the vehicle speed sensor 32 is provided on each wheel 11 and detects the rotational speed of the wheel 11. In the first embodiment, the signal output by the vehicle speed sensor 32 is a voltage value proportional to the rotation speed of the wheel 11 or a pulse wave indicating an interval according to the rotation speed of the wheel 11. The control device 100 calculates the vehicle speed V, which is the speed of the vehicle 10, by using the detection signal from the vehicle speed sensor 32. The control device 100 can also acquire information such as the mileage of the control device 100 by using the output signal of the vehicle speed sensor 32.

The shift position sensor 33 is a sensor that detects the position of the shift lever that is mechanically moved by the driver, and outputs a shift position signal SP, which is a signal indicating the detection result, to the control device 100. The control device 100 switches the traveling status of the vehicle 10 according to the position of the shift lever. The position of the shift lever is, for example, drive D when moving the vehicle 10 forward, reverse R when moving the vehicle 10 backward, neutral N when blocking the transmission of the driving force to the gear, and parking / stopping the vehicle 10. Including parking P at the time. The position of the shift lever may also include a brake B for restricting the movement of the vehicle 10, a manual M for accepting a manual operation of a gear change by the driver, and the like. The control device 100 switches the traveling state of the vehicle 10 by mechanically moving the shift lever by the driver. In the vehicle 10, the shift position signal SP may be configured to be switched by an electric switch operation regardless of the movement of the shift lever.

The travel mode switch 34 is a switch for the driver to switch the output characteristics of the torque output by the electric motor 20. The travel mode Mo selected and set by the travel mode switch 34 is output to the control device 100. In the first embodiment, the traveling modes of the vehicle 10 include, for example, an eco-mode in which fuel consumption is more important than torque, a sports mode in which fuel is more important than fuel consumption, and a balance between fuel consumption and torque. There is a normal mode to let you.

Refer to Fig. 2. The vehicle control unit 110 of the control device 100 determines the target torque Tt to be generated in the electric motor 20 in response to the acceleration command for the vehicle 10 represented by the accelerator opening degree Acc. In the first embodiment, the vehicle control unit 110 determines the target torque Tt using the vehicle speed V, the shift position signal SP, and the traveling mode Mo in addition to the accelerator opening degree Acc. Details of the process for determining the target torque Tt will be described later. The vehicle control unit 110 outputs a control signal for commanding the drive of the electric motor 20 at the target torque Tt to the electric motor control unit 21 and the monitoring unit 120.

The monitoring unit 120 determines the monitoring torque Ttw according to the acceleration command for the vehicle 10 represented by the accelerator opening degree Acc. In the first embodiment, the monitoring unit 120 determines the monitoring torque Ttw by using the vehicle speed V and the shift position signal SP in addition to the accelerator opening degree Acc. The monitoring unit 120 has a function of determining whether or not there is an abnormality in the control signal output from the vehicle control unit 110 to the electric motor control unit 21 by using the monitoring torque Ttw and the target torque Tt determined by the vehicle control unit 110. Have. Details of the step of determining the monitoring torque Ttw and the step of detecting an abnormality in the control signal will be described later.

When the monitoring unit 120 detects an abnormality in the control signal based on the determination, the monitoring unit 120 outputs a fail-safe signal FSS instructing the execution of the fail-safe processing of the motor 20 to the motor control unit 21. In the first embodiment, in the fail-safe process of the electric motor 20, the output torque of the electric motor 20 is set to a predetermined creep torque Tcr [Nm] or 0 [Nm] that causes a creep phenomenon in the vehicle 10. Will be done. In the fail-safe process of the electric motor 20, the relay provided in the power line connected to the electric motor 20 may be cut off.

The electric motor control unit 21 normally outputs an electric motor control signal MGS that sets a target torque Tt to the electric motor 20 according to a control signal from the vehicle control unit 110. The electric motor 20 is driven according to the target torque Tt. When the electric motor control unit 21 receives the fail-safe signal FSS from the monitoring unit 120, the electric motor control unit 21 outputs the electric motor control signal MGS instructing the execution of the fail-safe process to the electric motor 20. The electric motor 20 interrupts the drive at the target torque Tt and starts executing the fail-safe process.

Refer to FIG. The vehicle control unit 110 includes at least one central processing unit (CPU) 111, a memory 112, an input / output interface 113, and a bus 114. The CPU 111, the memory 112, and the input / output interface 113 are connected to each other via the bus 114 so as to be capable of bidirectional communication. The CPU 111 may be a single CPU or a plurality of CPUs that execute each program. Alternatively, the CPU 111 may be a multi-core type CPU capable of simultaneously executing a plurality of programs. The memory 112 is composed of a storage element such as a RAM that can be read and written by the CPU 111. The vehicle control unit 110 exerts various functions for controlling the running of the control device 100 by having the CPU 111 read a program or an instruction into the memory 112 and execute the program.

When executing the target torque determination process described later, the CPU 111 of the vehicle control unit 110 reads the target torque calculation program P1 stored in advance in a non-volatile and read-only storage device (not shown) such as a ROM into the memory 112. And execute. Further, in the target torque determination process, the CPU 111 of the vehicle control unit 110 reads out and uses the required torque map M1 stored in advance in the storage device (not shown) described above in the memory 112 in order to determine the target torque Tt. .. The required torque map M1 may be read into the memory 112 when it is used.

The above-mentioned accelerator opening sensor 31, vehicle speed sensor 32, shift position sensor 33, traveling mode switch 34, electric motor control unit 21, and monitoring unit 120 are connected to the input / output interface 113 via signal lines, respectively. In the target torque determination process, the CPU 111 receives inputs of the accelerator opening degree Acc, the vehicle speed V, the shift position signal SP, and the traveling mode Mo via the input / output interface 113. Further, the CPU 111 outputs the target torque Tt determined by the target torque determination process to the electric motor control unit 21 and the monitoring unit 120 via the input / output interface 113.

Refer to FIG. The monitoring unit 120 includes at least one central processing unit (CPU) 121, a memory 122, an input / output interface 123, and a bus 124. The CPU 121, the memory 122, and the input / output interface 123 are connected to each other via the bus 124 so as to be capable of bidirectional communication. The CPU 121 may be a single CPU or a plurality of CPUs that execute each program. Alternatively, the CPU 121 may be a multi-core type CPU capable of simultaneously executing a plurality of programs. The memory 122 is composed of a storage element such as a RAM that can be read and written by the CPU 121. The monitoring unit 120 exerts various functions for monitoring the control signal output from the vehicle control unit 110 to the electric motor control unit 21 by the CPU 121 reading a program or instruction into the memory 122 and executing the program or instruction.

In the monitoring unit 120, the CPU 121 reads the monitoring program P2 stored in advance in a non-volatile and read-only storage device (not shown) such as a ROM into the memory 122 and executes the monitoring torque determination process described later and various types. Execute monitoring processing. Further, the CPU 121 of the monitoring unit 120 reads and uses the monitoring torque map M2 previously stored in the storage device (not shown) described above in the memory 122 in order to determine the monitoring torque Ttw in the monitoring torque determination process. Further, in various monitoring processes described later, the CPU 121 reads the upper limit threshold value map MPα, the lower limit threshold value map MPβ, and the detection time map MPt stored in the above-mentioned storage device into the memory 122 and uses them. The maps M2, MPα, MPβ, and MPt may be read into the memory 122 when they are used, and may not be read into the memory 122 at the same time.

The above-mentioned accelerator opening sensor 31, vehicle speed sensor 32, shift position sensor 33, vehicle control unit 110, and electric motor control unit 21 are connected to the input / output interface 123 via signal lines, respectively. In the monitoring torque determination process and various monitoring processes, the CPU 121 receives inputs of the target torque Tt, the accelerator opening degree Acc, the vehicle speed V, and the shift position signal SP via the input / output interface 123. Further, when the CPU 121 decides to execute the fail-safe process in various monitoring processes, the CPU 121 outputs the fail-safe signal FSS to the electric motor control unit 21 via the input / output interface 123.

Refer to FIG. The control device 100 repeatedly executes the flow of the control process shown in FIG. 5 at a predetermined control cycle while the vehicle 10 is started. This control process is executed while the vehicle 10 is activated and the vehicle 10 is in a normal driving state. In step S10, the vehicle control unit 110 executes the target torque determination process, and in step S20, the monitoring unit 120 executes the monitoring torque determination process. In steps S30, S40, and S50, the monitoring unit 120 executes acceleration control monitoring processing, deceleration control monitoring processing, and code inversion monitoring processing, respectively. Hereinafter, the processing flow of each step S10 to S50 will be described in order.

Refer to FIG. In the target torque determination process, the vehicle control unit 110 determines the target torque Tt of the electric motor 20 according to the detected accelerator opening degree Acc. In step S100, the vehicle control unit 110 acquires the accelerator opening degree Acc, the vehicle speed V, and the traveling mode Mo. In step S102, the vehicle control unit 110 acquires the required torque Ta by using the accelerator opening degree Acc, the vehicle speed V, the traveling mode Mo, and the required torque map M1 shown in FIG. 7.

The required torque map M1 is set to have a relationship in which the required torque Ta is uniquely output with respect to the input accelerator opening degree Acc. The vehicle control unit 110 acquires the required torque Ta with respect to the accelerator opening degree Acc by using the required torque map M1. The required torque Ta is obtained as a value of 0 or more.

In the first embodiment, the relationship of the required torque Ta with respect to the accelerator opening degree Acc in the required torque map M1 is switched according to the traveling mode Mo. Therefore, even if the accelerator opening degree Acc is the same, the traveling mode Mo is required to be different. The torque Ta is set to a different value. In the example of the required torque map M1 of FIG. 7, the characteristic line L1 showing the relationship when the running mode Mo is in the sports mode is shown by a solid line, and the characteristic line L2 showing the relationship when the running mode Mo is in the eco mode is a dashed line. It is indicated by. In FIG. 7, for convenience, the illustration of the characteristic line showing the relationship when the traveling mode Mo is the normal mode is omitted. Both the characteristic line L1 and the characteristic line L2 show a relationship in which the required torque Ta increases as the accelerator opening degree Acc increases. On the characteristic line L1, the larger the accelerator opening degree Acc, the smaller the rate of increase of the required torque Ta with respect to the accelerator opening degree Acc. On the characteristic line L2, the larger the accelerator opening degree Acc, the larger the rate of increase of the required torque Ta with respect to the accelerator opening degree Acc.

In the first embodiment, the required torque Ta is set to a value corresponding to the vehicle speed V. In the first embodiment, the required torque map M1 is used after the set relationship is corrected according to the vehicle speed V. In another embodiment, the required torque map M1 may have a characteristic line indicating the relationship between the accelerator opening degree Acc and the required torque Ta set for each vehicle speed V. Alternatively, a plurality of required torque maps M1 for each vehicle speed V may be prepared in advance and selectively used according to the vehicle speed V.

In step S104 of FIG. 6, the vehicle control unit 110 executes a shift determination for determining the position of the shift lever using the shift position signal SP. The vehicle control unit 110 sets the target torque Tt to the required torque Ta in step S106 when the shift position signal SP is other than the reverse R, that is, when SP ≠ R. When the shift position signal SP is the reverse R, that is, when SP = R, the vehicle control unit 110 sets the target torque Tt to a value −Ta obtained by reversing the positive / negative of the required torque Ta in step S108. Set. As described above, the vehicle control unit 110 outputs the determined target torque Tt to the electric motor control unit 21 and the monitoring unit 120. As a result, the target torque determination process in step S10 shown in FIG. 5 is completed, and the monitoring torque determination process in step S20 is started.

Refer to FIG. In the monitoring torque determination process, the monitoring unit 120 determines the monitoring torque Ttw according to the accelerator opening degree Acc. In step S110, the monitoring unit 120 acquires the accelerator opening degree Acc and the vehicle speed V. In step S112, the monitoring unit 120 calculates the monitoring required torque Taw using the accelerator opening degree Acc, the vehicle speed V, and the monitoring torque map M2 shown in FIG.

In the monitoring torque map M2, a relationship is set in which the monitoring request torque Taw is uniquely output with respect to the input accelerator opening degree Acc. The monitoring unit 120 acquires the monitoring required torque Taw with respect to the accelerator opening degree Acc by using the monitoring torque map M2. The monitoring required torque Taw is obtained as a value of 0 or more. In the example of the monitoring torque map M2 shown in FIG. 9, the relationship of the monitoring required torque Taw with respect to the accelerator opening degree Acc is represented by the characteristic line L1w corresponding to the characteristic line L1 of the sports mode in the required torque map M1 of FIG. .. The characteristic line L1w shows a relationship in which the required torque Ta increases as the accelerator opening degree Acc increases. On the characteristic line L1w, the larger the accelerator opening degree Acc, the smaller the rate of increase of the required torque Ta with respect to the accelerator opening degree Acc.

In FIG. 9, for reference, the characteristic line L2w corresponding to the eco-mode characteristic line L2 in the required torque map M1 of FIG. 7 is shown by a broken line. In the first embodiment, even if the traveling mode Mo is in the eco mode, a monitoring request for the accelerator opening degree Acc is used by using the relationship represented by the characteristic line L1w corresponding to the characteristic line L1 of the sports mode in the required torque map M1. Torque Taw is acquired. Therefore, even if the traveling modes Mo are different, the monitoring required torque Taw obtained with respect to the accelerator opening degree Acc is the same. Here, in the required torque map M1 shown in FIG. 7, the relationship represented by the characteristic line L1 of the sport mode is the relationship in which the value of the required torque Ta obtained with respect to the accelerator opening degree Acc is the largest. Therefore, the monitoring required torque Taw obtained by using the relationship represented by the characteristic line L1w corresponding to the characteristic line L1 of the sports mode is always set to a value equal to or higher than the required torque Ta regardless of the traveling mode Mo.

In the first embodiment, the monitoring required torque Taw is set to a value corresponding to the vehicle speed V. In the first embodiment, the monitoring torque map M2 is used after the set relationship is corrected according to the vehicle speed V. In another embodiment, the monitoring torque map M2 may have a characteristic line indicating the relationship between the accelerator opening degree Acc and the monitoring required torque Taw for each vehicle speed V. Alternatively, a plurality of monitoring torque maps M2 for each vehicle speed V may be prepared in advance and may be selectively used according to the vehicle speed V.

In step S114 of FIG. 8, the monitoring unit 120 executes a shift determination for determining the position of the shift lever using the shift position signal SP. When the shift position signal SP is other than the reverse R, that is, when SP ≠ R, the monitoring unit 120 sets the monitoring torque Ttw to the monitoring request torque Taw in step S116. When the shift position signal SP is the reverse R, that is, when SP = R, the monitoring unit 120 sets the monitoring torque Ttw to a value −Taw in which the positive / negative of the monitoring request torque Taw is reversed in step S118. Set. As a result, the monitoring torque determination process in step S20 shown in FIG. 5 is completed, and the acceleration control monitoring process in step S30 is started. If it is detected that the vehicle 10 is not accelerating based on the detected acceleration command or brake command, the monitoring unit 120 may skip the acceleration control monitoring process in step S30. ..

Refer to FIG. The acceleration control monitoring process is a process in which the monitoring unit 120 detects and deals with an abnormality in the control signal when accelerating the vehicle 10. In step S200, the monitoring unit 120 sets the upper limit threshold value α according to the vehicle speed V. The monitoring unit 120 acquires and sets the upper limit threshold value α by using the vehicle speed V and the upper limit threshold value map MPα shown in FIG. The upper limit threshold value α is a predetermined boundary value that indicates the upper limit of the allowable error range between the target torque Tt and the monitoring torque Ttw.

The upper limit threshold map MPα has a relationship in which the upper limit threshold α is uniquely determined with respect to the vehicle speed V. According to the upper threshold map MPα, the upper threshold α is obtained as a value larger than 0. Further, according to the upper limit threshold map MPα, the larger the input vehicle speed V, the larger the output upper limit threshold α. Further, in relation to the upper limit threshold map MPα, the larger the vehicle speed V, the smaller the rate of change of the upper limit threshold α with respect to the vehicle speed V.

In step S205, the monitoring unit 120 sets the detection time t according to the accelerator opening degree Acc. The monitoring unit 120 acquires and sets the detection time t by using the accelerator opening degree Acc and the detection time map MPt shown in FIG. The detection time t indicates a limit value of a time during which an abnormality in the control signal is allowed to be continuously detected. The detection time t is obtained as a value greater than 0. In the example of the detection time map MPt of the first embodiment shown in FIG. 12, the relationship shown by the characteristic line Lt in which the detection time t becomes smaller as the accelerator opening degree Acc is larger is set in the detection time map MPt. There is. As a result, it is possible to suppress an increase in vehicle speed while an abnormality is detected. Further, in the detection time map MPt of the first embodiment, the reduction rate of the detection time t is relatively large in the region where the accelerator opening degree Acc is about several degrees. As a result, for example, it is possible to prevent erroneous detection of an abnormality in the control signal when only a slight accelerator operation is performed. Further, in the detection time map MPt of the first embodiment, when the accelerator opening degree Acc becomes larger than about several degrees, the reduction rate of the detection time t becomes remarkably small, and the detection time t is relative to the accelerator opening degree Acc. Does not decrease much. As a result, even when a half throttle or a partial throttle is frequently used, it is possible to detect an abnormality in the control signal with stable accuracy. The detection time t acquired in the acceleration control monitoring process is also used in the deceleration control monitoring process described later.

In step S210, the monitoring unit 120 determines whether or not the difference obtained by subtracting the monitoring torque Ttw from the target torque Tt is equal to or greater than the upper limit threshold value α. When Tt−Ttw ≧ α, 1 is added to the counter C in step S212. The counter C is a variable having an initial value of 0 and representing the number of times that an abnormality in the control signal is continuously detected while the acceleration control monitoring process is repeated in a predetermined execution cycle. When Tt—Ttw ≧ α, the monitoring unit 120 determines that an abnormality in the control signal during acceleration of the vehicle 10 has been detected, and increments the counter C.

Here, refer to FIG. FIG. 9 shows the upper limit boundary line BU in which the characteristic line L1w is shifted by + α. In the acceleration control monitoring process of the first embodiment, the monitoring unit 120 detects an abnormality in the control signal when the target torque Tt is included in the acceleration hazard region which is a region above the upper limit boundary line BU.

As described above, the monitoring required torque Taw acquired using the monitoring torque map M2 is acquired using the relationship corresponding to the sports mode represented by the characteristic line L1w. Therefore, the monitoring required torque Taw is always set to a value equal to or higher than the required torque Ta obtained in the sports mode regardless of the current traveling mode Mo. The reason for this is that when the driving mode Mo is in the sports mode, there is the highest possibility that an abnormality in the control signal that is subject to fail-safe processing occurs, and it is desirable to make a judgment based on the sports mode. ..

In step S210 of FIG. 10, when Tt-Ttw <α, 0 is assigned to the counter C in step S214. When Tt—Ttw <α, the monitoring unit 120 determines that the abnormality of the control signal during acceleration of the vehicle 10 is not continuously detected, and initializes the counter C.

In step S220, the monitoring unit 120 determines whether or not the counter C is equal to or longer than the detection time t acquired in step S205. As described above, the counter C indicates the number of times that the abnormality of the control signal is continuously and repeatedly detected in a predetermined cycle, and indicates the time during which the abnormality of the control signal is continued. That is, the fact that C ≧ t indicates that the abnormality of the control signal at the time of accelerating the vehicle 10 continues beyond the permissible time. Therefore, when C ≧ t, the monitoring unit 120 determines in step S230 to execute the fail-safe process, assuming that the acceleration determination conditions including the conditions of steps S210 and S220 are satisfied. The monitoring unit 120 outputs a fail-safe signal FSS instructing the execution of the fail-safe process to the electric motor control unit 21, and ends the acceleration control monitoring process. The electric motor control unit 21 outputs an electric motor control signal MGS that commands the electric motor 20 to execute the fail-safe process. As a result, the normal driving state of the vehicle 10 is interrupted, so that the control process of FIG. 5 ends in the middle.

On the other hand, in step S220, when C <t, the monitoring unit 120 ends the acceleration control monitoring process as it is. In this case, it can be determined that the abnormality of the control signal during the acceleration control of the vehicle 10 is not continuously detected so as to be necessary to deal with it. After that, the monitoring unit 120 starts executing the deceleration control monitoring process in step S40 shown in FIG. If it is detected that the vehicle 10 is decelerating based on the detected acceleration command or brake command, the monitoring unit 120 may skip the deceleration control monitoring process in step S40. ..

Refer to FIG. The deceleration control monitoring process is a process in which the monitoring unit 120 detects an abnormality in the control signal when decelerating the vehicle 10 and deals with it. In step S300, the monitoring unit 120 sets the lower limit threshold value β according to the vehicle speed V. The monitoring unit 120 acquires and sets the lower limit threshold value β by using the vehicle speed V and the lower limit threshold value map MPβ shown in FIG. The lower limit threshold value β is a predetermined boundary value that indicates an acceptable lower limit of the target torque Tt during deceleration.

The lower limit threshold map MPβ has a relationship in which the lower limit threshold β is uniquely determined with respect to the vehicle speed V. According to the lower threshold map MPβ, the lower threshold β is obtained as a value smaller than 0. Further, according to the lower limit threshold map MPβ, the larger the input vehicle speed V, the smaller the output lower limit threshold β. Further, in relation to the lower limit threshold map MPβ, the larger the vehicle speed V, the smaller the rate of change of the lower limit threshold β with respect to the vehicle speed V.

In step S305, the monitoring unit 120 acquires the detection time t. In the first embodiment, the monitoring unit 120 also uses the detection time t acquired in the acceleration control monitoring process in the deceleration control monitoring process. When the execution of the acceleration control monitoring process is skipped, the monitoring unit 120 uses the detection time map MPt as in step S205 of the acceleration control monitoring process to detect the detection time according to the accelerator opening degree Acc. Set t.

In step S310, the monitoring unit 120 determines whether or not the target torque Tt is equal to or less than the lower limit threshold value β. When Tt ≦ β, 1 is added to the counter C in step S312. That is, when Tt ≦ β, the monitoring unit 120 determines that an abnormality in the control signal during deceleration of the vehicle 10 has been detected, and increments the counter C.

Refer to FIG. FIG. 7 shows a lower limit boundary line BL indicating a torque corresponding to the lower limit threshold value β. In the deceleration control monitoring process of the first embodiment, the monitoring unit 120 detects an abnormality in the control signal when the target torque Tt is included in the deceleration hazard region which is a region below the lower limit boundary line BL. In the deceleration control monitoring process, the lower limit boundary line BL is determined according to the vehicle speed V and is constant regardless of the accelerator opening degree Acc.

On the other hand, in step S310 shown in FIG. 13, when Tt> β, 0 is assigned to the counter C in step S314. When Tt> β, the monitoring unit 120 determines that the abnormality of the control signal during deceleration of the vehicle 10 is not continuously detected, and initializes the counter C.

In step S320, the monitoring unit 120 determines whether or not the counter C is equal to or longer than the detection time t acquired in step S305. The fact that C ≧ t indicates that the abnormality of the control signal during deceleration of the vehicle 10 continues beyond the permissible detection time t. Therefore, when C ≧ t, the monitoring unit 120 decides to execute the fail-safe process in step S330, assuming that the deceleration determination condition including the condition of step S310 and the condition of step S320 is satisfied. To do. The monitoring unit 120 outputs a fail-safe signal FSS instructing the execution of the fail-safe process to the electric motor control unit 21, and ends the deceleration control monitoring process. The electric motor control unit 21 outputs an electric motor control signal MGS that commands the electric motor 20 to execute the fail-safe process. As a result, the normal driving state of the vehicle 10 is interrupted, so that the control process of FIG. 5 ends in the middle.

On the other hand, if C <t in step S320, the monitoring unit 120 ends the acceleration control monitoring process as it is. In this case, it can be determined that the abnormality of the control signal during the deceleration control of the vehicle 10 is not continuously detected so as to be necessary to deal with it. After that, the monitoring unit 120 starts executing the code reversal monitoring process in step S50 shown in FIG.

Refer to FIG. The code reversal monitoring process is a process in which the monitoring unit 120 detects and deals with the occurrence of an abnormality in the control signal in which the positive / negative of the target torque Tt output from the vehicle control unit 110 to the electric motor control unit 21 is reversed. The positive / negative reversal of the target torque Tt can occur, for example, due to a communication error between the vehicle control unit 110 and the electric motor control unit 21.

In step S410, the monitoring unit 120 executes a shift determination for determining the position of the shift lever using the shift position signal SP. This is because the determination condition is switched between the case where the shift position signal SP is the reverse R and the case where the shift position signal SP is other than the reverse R.

When the shift position signal SP is other than the reverse R, that is, when SP ≠ R, the monitoring unit 120 sets the target torque Tt to a negative value of the predetermined determination threshold value γ in step S420. -Judge whether it is smaller than γ. The determination threshold value γ is a value corresponding to a predetermined creep torque Tcr [Nm], and is a positive value. The determination threshold value γ may be set to 0 [Nm] instead of the value corresponding to the creep torque Tcr [Nm].

If Tt <-γ in step S420, the positive / negative of the target torque may be reversed, and the target torque may be negative even though the shift position signal SP is not the reverse R. .. Therefore, the monitoring unit 120 determines whether the monitoring torque Ttw is positive or negative in step S422, and verifies whether or not the negative target torque is due to an abnormality in the control signal. In step S422, the monitoring unit 120 determines whether or not the monitoring torque Ttw is larger than the determination threshold value γ.

In step S422, when Ttw> γ, the positive and negative of the target torque and the monitoring torque Ttw do not match. Therefore, in this case, the monitoring unit 120 adds 1 to the counter CFD in step S424, assuming that an abnormality in the control signal in which the positive / negative of the target torque is reversed has occurred. The counter CFD is a variable that represents the number of times that positive / negative inversion of the target torque Tt is continuously detected while the initial value is 0 and the code inversion monitoring process is repeated in a predetermined execution cycle. As described above, when SP ≠ R, the monitoring unit 120 is a control signal in which the positive / negative of the target torque Tt output to the motor control unit 21 is inverted when Tt <−γ and Ttw> γ. It is determined that the abnormality of is detected, and the counter CFD is incremented.

On the other hand, when Tt <-γ is not satisfied in step 420, the monitoring unit 120 assumes that the positive and negative of the target torque are not reversed, substitutes 0 for the counter CFD in step S426, and initializes the counter CFD. To do. Further, when Ttw> γ is not satisfied in step 422, the positive and negative values match the monitoring torque Ttw even if the target torque is a negative value. In this case, it is considered that the target torque is appropriately set to a negative value in terms of control of the electric motor 20. Therefore, the monitoring unit 120 substitutes 0 for the counter CFD and initializes the counter CFD in step S426, assuming that the positive and negative of the target torque are not reversed.

In the shift determination in step S410, when the shift position signal SP is reverse R, that is, when SP = R, the monitoring unit 120 determines in step S430 whether the target torque Tt is larger than the determination threshold value γ. To judge. When Tt> γ in step S430, there is a possibility that the positive / negative of the target torque is reversed and the target torque is positive even though the shift position signal SP is the reverse R. Therefore, the monitoring unit 120 determines whether the monitoring torque Ttw is positive or negative in step S432, and verifies whether or not the positive target torque is due to an abnormality in the control signal. In step S432, the monitoring unit 120 determines whether or not the monitoring torque Ttw is larger than the determination threshold value γ.

In step S432, when Ttw <-γ, the positive and negative of the target torque and the monitoring torque Ttw do not match. Therefore, in this case, the monitoring unit 120 adds 1 to the counter CFD in step S434, assuming that an abnormality in the control signal in which the positive / negative of the target torque is reversed has occurred. As described above, when SP = R, the monitoring unit 120 has a control signal in which the positive / negative of the target torque Tt output to the motor control unit 21 is inverted when Tt> γ and Ttw <−γ. It is determined that the abnormality of is detected, and the counter CFD is incremented.

On the other hand, when Tt> γ is not satisfied in step 430, the monitoring unit 120 assumes that the positive and negative of the target torque are not reversed, substitutes 0 for the counter CFD in step S436, and initializes the counter CFD. .. Further, when Ttw <-γ is not satisfied in step 432, even if the target torque is a positive value, the positive and negative values match the monitoring torque Ttw. In this case, it is considered that the target torque is appropriately set to a positive value in terms of control of the electric motor 20. Therefore, the monitoring unit 120 substitutes 0 for the counter CFD and initializes the counter CFD in step S436, assuming that the positive and negative of the target torque are not reversed.

In step S440, the monitoring unit 120 determines whether or not the counter CFD is equal to or longer than the predetermined detection time ct. As described above, the counter CFD indicates the number of times that the abnormality of the control signal in which the positive / negative inversion of the target torque Tt occurs is continuously and repeatedly detected in a predetermined control cycle, and the time during which the abnormality is continued is indicated. Represents. That is, the fact that CFD ≧ tt indicates that the abnormality of the control signal in which the positive / negative inversion of the target torque Tt occurs continues beyond the permissible time.

When CFD ≧ tc, the monitoring unit 120 fails in step S450, assuming that the determination conditions including the conditions of steps S420 and S422, or the conditions of steps S430 and S432 and the conditions of step S440 are satisfied. Decide to perform safe processing. The monitoring unit 120 outputs a fail-safe signal FSS instructing the execution of the fail-safe processing to the electric motor control unit 21, and ends the code inversion monitoring processing. The electric motor control unit 21 outputs an electric motor control signal MGS that commands the electric motor 20 to execute the fail-safe process. As a result, the normal driving state of the vehicle 10 is interrupted, so that the control process of FIG. 5 ends.

In step S440, if CFD ≧ tk, the monitoring unit 120 ends the code inversion monitoring process and restarts the flow of the control process shown in FIG. 5 from step S10. In the first embodiment, the detection time ct, which is the determination condition in step S440, is set to a number smaller than 1. As a result, when an abnormality in which the positive / negative of the target torque Tt is reversed is detected even once, the execution of the fail-safe process is determined in step S450.

As described above, according to the control device 100 of the first embodiment, the abnormality of the control signal in which the positive / negative of the target torque Tt of the electric motor 20 is reversed by the code inversion monitoring process is defined as the target torque Tt and the monitoring torque Ttw. Can be appropriately detected by a simple determination method using. Further, in the code reversal monitoring process, the execution of the fail-safe process of the electric motor 20 is determined when the determination condition including the condition that the positive and negative of the target torque Tt and the monitoring torque Ttw do not match is satisfied. As a result, the abnormality of the control signal in which the positive and negative of the target torque Tt output to the electric motor control unit 21 is reversed is appropriately dealt with, and the rotation direction of the electric motor 20 is controlled in the opposite direction against the operation of the driver. It is possible to avoid the occurrence of various problems. Therefore, the reliability of the control of the electric motor 20 can be improved.

In the control device 100 of the first embodiment, when the vehicle 10 is accelerated, the electric motor control unit 21 is connected to the electric motor when at least a determination condition including a condition that Tt—Ttw is equal to or higher than the upper limit threshold value α corresponding to the vehicle speed V is satisfied. Command the execution of 20 fail-safe processes. Therefore, it is suppressed that the vehicle 10 accelerates more than expected for the acceleration command. Further, the control device 100 of the first embodiment satisfies the determination condition including the condition that the target torque Tt becomes smaller than the lower limit threshold value β corresponding to the vehicle speed V when the vehicle 10 is decelerated, the electric motor control unit 21 Is instructed to execute the fail-safe process of the electric motor 20. Therefore, it is suppressed that the vehicle 10 decelerates so as to give the driver an abnormal load of gravitational acceleration. According to the control device 100 of the first embodiment, the code inversion monitoring process is executed in addition to the acceleration control monitoring process and the deceleration control monitoring process. Therefore, for example, when the vehicle 10 is traveling with the creep torque Tcr, the abnormality of the control signal due to the positive / negative reversal of the target torque Tt, which is not detected by the acceleration control monitoring process or the deceleration control monitoring process, is defined as a reference. It can be detected accurately by the reverse monitoring process.

2. 2. Second embodiment:
See FIG. The code reversal monitoring process in the second embodiment is the same as the code reversal process in the first embodiment except that steps S400 and S402 are added. Unless otherwise specified, the configuration of the control device 100 and the vehicle 10 including the control device 100 in the second embodiment is substantially the same as the configuration described with reference to FIGS. 1 to 4 in the first embodiment.

In the code reversal monitoring process of the second embodiment, the monitoring unit 120 of the control device 100 first determines in step S400 whether or not the vehicle speed V is 0 [km / h]. When the vehicle speed V is 0 [km / h], the monitoring unit 120 determines in step S402 whether or not the accelerator is off, that is, Acc = 0, when the acceleration command is not given. When the accelerator is off, the monitoring unit 120 executes the processes after step S410 in the same manner as described in the first embodiment. If the vehicle speed V is not 0 [km / h] in step S400, or if the acceleration command is detected in step S402, the monitoring unit 120 ends the code reversal monitoring process as it is.

As described above, according to the control device 100 of the second embodiment, is the positive / negative of the target torque Tt reversed when the vehicle speed V is 0 [km / h] and the acceleration command is not given? Whether or not to determine is executed. As a result, for example, it is possible to prevent the target torque Tt when the electric motor 20 is generating power from being erroneously determined that the positive and negative values are reversed from the original values. Therefore, it is possible to more appropriately and more accurately detect the occurrence of an abnormality in the control signal in which the positive and negative of the target torque Tt are reversed. In addition, according to the control device 100 of the second embodiment and the control method of the vehicle 10 realized by the control device 100, various effects similar to those described in the first embodiment can be obtained. ..

3. 3. Other embodiments:
The various configurations described in each of the above embodiments can be modified, for example, as follows. Each of the other embodiments described below, like each of the above embodiments, is positioned as an example of an embodiment for carrying out the disclosure.

-Other embodiment 1:
In each of the above embodiments, at least one of the acceleration control monitoring process and the deceleration control monitoring process may not be executed.

-Other embodiment 2:
In each of the above embodiments, the vehicle control unit 110 does not have to execute the control switching according to the traveling mode Mo. Further, the vehicle control unit 110 may be configured to be capable of traveling in a mode different from the eco mode, the sports mode, and the normal mode.

-Other embodiment 3:
The determination conditions for determining the execution of the fail-safe process in each of the above embodiments include the condition of step S220 of FIG. 10, the condition of step S320 of FIG. 13, and the condition of step S440 of FIGS. 15 and 16. It may be omitted.

4. Others:
The technique of the present disclosure can also be realized in various forms other than the vehicle control method and the control system. For example, it can be realized in the form of a vehicle control device, a vehicle equipped with the vehicle, a traffic management system, a computer program for realizing the control method, and a storage medium in which the computer program is recorded.

The controls and methods thereof described in the present disclosure are realized by a dedicated computer provided by configuring a processor and memory programmed to perform one or more functions, embodied by a computer program. May be done. Alternatively, the controls and methods thereof described in the present disclosure may be implemented by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the controls and methods thereof described in the present disclosure are a combination of a processor and memory programmed to perform one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured by. Further, the computer program may be stored in a computer-readable non-transitional tangible recording medium as an instruction executed by the computer.

The technique of the present disclosure is not limited to the above-described embodiment and other embodiments, and can be realized by various configurations within a range not deviating from the purpose. For example, the technical features in the embodiments corresponding to the technical features in each form described in the column of the outline of the invention may be used to solve some or all of the above-mentioned problems, or one of the above-mentioned effects. It is possible to replace or combine as appropriate to achieve a part or all. In addition, the technical features are not limited to those described in the present specification as not essential, and if the technical features are not described as essential in the present specification, they may be appropriately deleted. Is possible.

Claims (6)

1. A control device (100) that controls the running of a vehicle (10) that runs by the driving force of an electric motor (20).
   A vehicle control unit (110) that determines a target torque (Tt) to be generated in the electric motor according to the accelerator opening (Acc) and outputs a control signal instructing the drive of the electric motor at the target torque.
   The monitoring torque (Ttw) is determined according to the accelerator opening, and when the determination condition including the condition that the positive / negative of the target torque and the monitoring torque do not match is satisfied, the fail-safe process of the electric motor is executed. The monitoring unit (120) that commands
   A control device.
2. The control device according to claim 1.
   The monitoring unit executes a control for determining whether or not the target torque and the positive / negative of the monitoring torque match when the speed of the vehicle is 0 and the accelerator opening is 0. apparatus.
3. The control device according to claim 1 or 2.
   When the vehicle is accelerating, the monitoring unit includes a condition that the value obtained by subtracting the monitoring torque from the target torque is equal to or higher than a predetermined upper limit threshold value (α) according to the speed of the vehicle. A control device that commands execution of fail-safe processing of the electric motor when the determination condition is satisfied.
4. The control device according to any one of claims 1 to 3.
   When the monitoring unit satisfies the deceleration determination condition including the condition that the target torque is equal to or less than a predetermined lower limit threshold value (β) according to the speed of the vehicle when the vehicle is decelerating. A control device that commands the execution of fail-safe processing of the electric motor.
5. It ’s a vehicle,
   An electric motor that generates the driving force used to drive the vehicle, and
   The control device according to any one of claims 1 to 4.
   A vehicle equipped with.
6. It is a control method for a vehicle that travels by the driving force of an electric motor.
   The process of determining the target torque of the electric motor according to the accelerator opening, and
   A step of determining a monitoring torque according to the accelerator opening degree and executing a fail-safe process of the electric motor when a determination condition including a condition in which the positive / negative of the target torque and the monitoring torque do not match is satisfied. ,
   A control method that comprises.

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