Control device for a mobile body

Abstract

A control device (80) is provided in a mobile body having a motor (31) and a battery (33) and capable of obtaining a braking force through regenerative drive of the motor and action of a brake device (41, 42, 43, 44). The control device includes an abnormality detection section (61) that detects abnormality of the brake device, and a motor control section (60) that controls the motor. When a regenerative torque generated by regenerative drive of the motor while the brake device is normal is set to a normal regenerative torque, the motor control section, when abnormality of the brake device is detected by the abnormality detection section, causes the motor to perform regenerative drive in a manner to generate an abnormal-time regenerative torque larger than the normal regenerative torque for a period from a time point at which the abnormality is detected to a lapse of a prescribed grace time regardless of a state of charge of the battery.

Description

[0001] Citation of relevant applications

[0002] This application claims priority to Japanese Patent Application No. 2020-119785, filed on July 13, 2020, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a control device for a moving body. Background Technology

[0004] Conventionally, there have been vehicles as described in Patent Document 1. The vehicle described in Patent Document 1 includes an electric motor for driving the vehicle and a control device for controlling the electric motor. When an abnormality is detected in the vehicle's braking system, the control device generates braking force by regeneratively driving the electric motor, thereby stopping the vehicle.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent No. 6064375. Summary of the Invention

[0008] When an abnormality is detected in the braking system, if the motor is used for regenerative driving while the battery is fully charged or nearly fully charged, the battery may become overcharged. If this overcharge continues, the worst-case scenario is that the battery life will be significantly reduced, or worse, the battery may become inoperable.

[0009] Furthermore, such technical problems are not limited to vehicles, but are common to all moving bodies powered by electric motors.

[0010] The purpose of this disclosure is to provide a control device that can stop a moving body while avoiding the worst-case scenario of a battery malfunction when a braking device malfunctions.

[0011] One aspect of the control device disclosed herein includes: an electric motor that operates as a power source for movement; a battery that supplies power to the electric motor and generates electricity through the regenerative drive of the electric motor; and a moving body capable of obtaining braking force through the regenerative drive of the electric motor and the operation of a braking device. The control device includes: an anomaly detection unit that detects anomalies in the braking device; and an electric motor control unit that controls the electric motor. When the regenerative torque generated by the electric motor during regenerative drive when the braking device is normal is set as the normal regenerative torque, when the anomaly detection unit detects an anomaly in the braking device, the electric motor control unit, during the period from the time of anomaly detection until a predetermined grace period has elapsed, regenerates the electric motor to generate an extraordinary regenerative torque greater than the normal regenerative torque, regardless of the battery's state of charge.

[0012] The battery does not immediately cause an anomaly when it reaches an overcharged state; in fact, there is a certain grace period between reaching an overcharged state and the occurrence of the worst-case anomaly. Therefore, as described above, when an anomaly in the braking device is detected, if the motor is regeneratively driven during the period from the time the anomaly is detected until the predetermined grace period has elapsed, braking force can be obtained while preventing the worst-case battery anomaly, even assuming the battery is overcharged. Thus, the moving body can be stopped. Attached Figure Description

[0013] Figure 1 This is a block diagram illustrating the schematic structure of the vehicle according to the first embodiment.

[0014] Figure 2 This is a block diagram illustrating the schematic structure of the vehicle control device according to the first embodiment.

[0015] Figure 3 This is a block diagram showing the structure of the EVECU in the first embodiment.

[0016] Figure 4 It is a mapping diagram used to calculate the basic torque command value T10* based on the accelerator pedal operation amount AP, shift position SP, and vehicle speed VC used by the EVECU of the first embodiment.

[0017] Figure 5 It is a mapping diagram showing the relationship between vehicle speed VC and final torque command value T20* used by the EVECU of the first embodiment.

[0018] Figure 6 This is a flowchart illustrating the steps of the processing performed by the EVECU of the first embodiment.

[0019] Figure 7This is a flowchart illustrating the steps of fail-safe control performed by the EVECU of the first embodiment.

[0020] Figure 8 It is a mapping diagram showing the relationship between the accelerator pedal depress amount AP and the final torque command value T20* used by the EVECU of the first embodiment.

[0021] Figure 9 (A) to (G) are timing diagrams representing the SOC value of the battery in the vehicle of the first embodiment, the amount of accelerator pedal depressed AP, the vehicle speed VC, the braking force of the vehicle 10, the final torque command value T20*, the lower limit value of the duty cycle DMmin, and the progression of the counter C.

[0022] Figure 10 This is a flowchart illustrating the steps of the processing performed by the EVECU in the second embodiment.

[0023] Figure 11 It is a mapping diagram showing the relationship between the battery charging current value Ib and the specified value ΔC used by the EVECU of the second embodiment.

[0024] Figure 12 This is a flowchart illustrating the steps of the processing performed by the EVECU in the third embodiment.

[0025] Figure 13 This is a flowchart illustrating the steps of the final torque command value setting process executed by the EVECU of the third embodiment.

[0026] Figure 14 It is a mapping diagram showing the relationship between the counter C and the coefficient Kwin used by the EVECU of the third embodiment. Detailed Implementation

[0027] The implementation of the vehicle control device will now be described with reference to the accompanying drawings. For ease of understanding, the same symbols will be used to label the same components in each drawing whenever possible, and repeated descriptions will be omitted.

[0028] <First Implementation>

[0029] First, a schematic structure of a vehicle equipped with the control device of the first embodiment will be described.

[0030] Figure 1 The vehicle 10 shown in this embodiment is a so-called electric vehicle that operates using an electric generator 31 as its power source. In this embodiment, the vehicle 10 is equivalent to a moving body, and the driving and stopping of the vehicle 10 are equivalent to the movement and stopping of the moving body. Figure 1 As shown, the vehicle 10 includes a steering device 20, a power system 30, and braking devices 41-44.

[0031] The steering system 20 has a driver-operated steering wheel 21 that is not mechanically connected to the wheels 11 and 12, a so-called drive-by-wire structure. The steering system 20 includes a steering angle sensor 22 and a steering mechanism 23. The steering angle sensor 22 detects the rotation angle of the steering wheel 21, i.e., the steering angle. The steering mechanism 23 changes the steering angle of the right front wheel 11 and the left front wheel 12 based on the steering angle detected by the steering angle sensor 22.

[0032] The power system 30 includes a motor generator 31, an inverter unit 32, a battery 33, and a differential gear 34.

[0033] The inverter device 32 converts the DC power supplied from the battery 33 into three-phase AC power and supplies the converted three-phase AC power to the electric generator 31.

[0034] The electric generator 31 operates as an electric motor when the vehicle 10 accelerates. When operating as an electric motor, the electric generator 31 is driven by three-phase AC power supplied from the inverter device 32. The power of the electric generator 31 is transmitted from its output shaft 310 to the right rear wheel 13 and the left rear wheel 14 via the differential gear 34 and the drive shaft 35, thereby applying torque to the rear wheels 13 and 14 to accelerate the vehicle 10.

[0035] The electric generator 31 can operate as a generator when the vehicle 10 is decelerating. When operating as a generator, the electric generator 31 generates electricity via regenerative braking. Braking force is applied to the rear wheels 13 and 14 via the regenerative braking of the electric generator 31. The three-phase AC power generated by the regenerative braking of the electric generator 31 is converted into DC power by the inverter device 32 and used to charge the battery 33.

[0036] Thus, in the vehicle 10 of this embodiment, the right rear wheel 13 and the left rear wheel 14 function as drive wheels, while the right front wheel 11 and the left front wheel 12 function as driven wheels. Hereinafter, for convenience, the right rear wheel 13 and the left rear wheel 14 will be collectively referred to as "drive wheels 13 and 14".

[0037] Braking devices 41 to 44 are respectively installed on wheels 11 to 14 of vehicle 10. Braking devices 41 to 44 include, for example, a rotating body that rotates integrally with wheels 11 to 14; a brake pad disposed opposite to the rotating body; and a hydraulic circuit that causes the brake pad to contact and separate from the rotating body by applying hydraulic pressure to the brake pad. In braking devices 41 to 44, the brake pad contacts the rotating body through the hydraulic pressure of the hydraulic circuit, thereby applying frictional force to the rotating body to apply braking force to wheels 11 to 14.

[0038] Next, refer to Figure 2 The electrical structure of vehicle 10 will be described in detail.

[0039] like Figure 2 As shown, vehicle 10 includes a throttle position sensor 50, a shift position sensor 51, an acceleration sensor 52, a vehicle speed sensor 53, a brake position sensor 54, and a notification device 55. Additionally, as components performing various controls, vehicle 10 includes an EV (Electric Vehicle) ECU (Electronic Control Unit) 60, a brake ECU 61, an MGECU 62, and a BMU (Battery Management Unit) 63. These elements constitute the control device 80 of this embodiment. In this embodiment, the EVECU 60 corresponds to the electric motor control unit.

[0040] The throttle position sensor 50 detects the amount of throttle pedal operation in the vehicle 10 and outputs a signal corresponding to the detected throttle pedal operation to the EVECU 60. In this embodiment, the throttle position sensor 50 is equivalent to a throttle position detection unit.

[0041] The shift position sensor 51 detects the operating position of the gear lever of the vehicle 10 and outputs a signal corresponding to the detected operating position of the gear lever to the EVECU 60.

[0042] Acceleration sensor 52 detects the acceleration of vehicle 10 in the direction of travel and outputs a signal corresponding to the detected acceleration to EVECU 60.

[0043] The vehicle speed sensor 53 detects the vehicle speed in the direction of travel of the vehicle 10 and outputs the signal corresponding to the detected vehicle speed to the EVECU 60.

[0044] The brake position sensor 54 detects the operating position of the brake pedal of the vehicle 10 and outputs a signal corresponding to the detected operating position of the brake pedal to the brake ECU 61.

[0045] The notification device 55 is a device for notifying both the interior and exterior of the vehicle. Examples of the notification device 55 include a speaker that notifies the interior by emitting sound into the vehicle, and a lighting device that notifies the exterior by illuminating the hazard lights and brake lights.

[0046] Each ECU 60 to 63 is centered around a microcomputer with a CPU, memory, etc. Each ECU 60 to 63 can receive and send various information via an in-vehicle network 70 such as CAN installed in the vehicle 10.

[0047] The brake ECU 61 controls the braking devices 41 to 44 by executing a program pre-stored in the memory. For example, when the brake ECU 61 detects that the brake pedal is depressed based on the operating position of the brake pedal detected by the brake position sensor 54, it drives the braking devices 41 to 44 to apply braking force to each wheel 11 to 14.

[0048] Furthermore, when the brake ECU 61 detects that the brake pedal has been depressed, it sends a braking torque command value T30* to the EVECU 60. The braking torque command value T30* is the target value of the braking torque that should be output from the electric generator 31 to decelerate the vehicle 10. The brake ECU 61 sets the braking torque command value T30* in such a way that the sum of the braking force obtained by the drive brake devices 41-44 and the braking force obtained by the regenerative drive of the electric generator 31 is the target value of the braking force required by the vehicle 10. Based on this braking torque command value T30*, the EVECU 60 causes the electric generator 31 to perform regenerative drive, thereby applying braking force to the drive wheels 13 and 14 from the electric generator 31.

[0049] The EVECU 60 is the part that comprehensively controls the driving state of the vehicle 10 by executing programs pre-stored in memory. For example... Figure 3 As shown, the EVECU 60 has a basic torque command value calculation unit 600 and a torque command value adjustment unit 601.

[0050] The output signals of the throttle position sensor 50, shift position sensor 51, and vehicle speed sensor 53 are input to the basic torque command value calculation unit 600. Based on the output signals of these sensors, the basic torque command value calculation unit 600 acquires information on the throttle pedal operation amount AP, shift position SP, and vehicle speed VC, and uses this information to... Figure 4 The mapping shown is used to calculate the basic torque command value T10*. The basic torque command value T10* is the target value of the torque that should be output from the electric generator 31. For example, when accelerating the vehicle 10, in other words, when driving the electric generator 31, the basic torque command value T10* is set to a positive value. When decelerating the vehicle 10, in other words, when regenerating the electric generator 31, the basic torque command value T10* is set to a negative value. The basic torque command value calculation unit 600 outputs the calculated basic torque command value T10* to the torque command value adjustment unit 601.

[0051] If the torque command value adjustment unit 601 does not send the braking torque command value T30* from the brake ECU 61, it sends the basic torque command value T10* as the final torque command value T20* to the inverter device 32.

[0052] When the braking torque command value adjustment unit 601 receives a braking torque command value T30* from the braking ECU 61, it prioritizes the braking torque command value T30* over the basic torque command value T10* and sends the braking torque command value T30* as the final torque command value T20* to the inverter device 32. The braking torque command value T30* is set to a negative value, which is the value at which the electric generator 31 performs regenerative drive.

[0053] The MGECU 62 is installed in the inverter unit 32. The MGECU 62 controls the electric generator 31 based on the final torque command value T20* sent from the torque command value adjustment unit 601. Specifically, the MGECU 62 calculates the duty cycle value DM based on the final torque command value T20*, and drives the inverter unit 32 based on the calculated duty cycle value DM, thereby controlling the electric generator 31. Furthermore, the duty cycle value DM is set within the range of "-100% ≤ DM ≤ 100%". When the duty cycle value DM is "0% < DM ≤ 100%", the electric generator 31 consumes power from the battery 33 for operation. When the duty cycle value DM is "-100% ≤ DM < 0%", the electric generator 31 performs regenerative operation.

[0054] As described above, when no braking torque command value T30* is sent from the brake ECU 61 to the EVECU 60, the electric generator 31 outputs either a drive torque or a regenerative torque corresponding to the basic torque command value T10*. Furthermore, drive torque refers to the torque output from the electric generator 31 via electrical supply, and is a torque capable of accelerating the vehicle 10. Regenerative torque is the torque generated by the regenerative drive of the electric generator 31, and is a torque capable of decelerating the vehicle 10. On the other hand, when a braking torque command value T30* is sent from the brake ECU 61 to the EVECU 60, the electric generator 31 outputs a regenerative torque corresponding to the braking torque command value T30*.

[0055] like Figure 2 As shown, BMU 63 detects the SOC (State of Charge) value of battery 33 and manages the state of battery 33 based on the detected SOC value. Furthermore, based on defining the fully discharged state of battery 33 as "0%" and the fully charged state of battery 33 as "100%", the SOC value represents the state of charge of battery 33 as a range of "0% to 100%". In this embodiment, BMU 63 corresponds to the battery control unit.

[0056] Furthermore, if the battery 33 is fully charged or nearly fully charged, and charging is performed via regenerative braking by the electric generator 31, the battery 33 will become overcharged. If this overcharge continues, there is a possibility of the worst-case scenario, such as a significant reduction in battery life or, in some cases, the battery failing to function. Therefore, this is not preferred. Thus, in such a situation, to avoid overcharging, the BMU 63 of this embodiment requests a charge limit to the EVECU 60.

[0057] Specifically, BMU 63 monitors whether the SOC value of battery 33 is above a specified value. If the SOC value of battery 33 is above the specified value, it determines that battery 33 is in a fully charged or nearly fully charged state. When battery 33 is in a fully charged or nearly fully charged state, BMU 63 sends a request to EVECU 60 to limit regenerative power generation from electric generator 31 to battery 33. In this embodiment, this request is equivalent to a charge limit request. Figure 3 As shown, the charge limit request sent from the EVECU 60 is received by the torque command value adjustment unit 601 of the EVECU 60. Upon receiving the charge limit request, the torque command value adjustment unit 601 sets a final torque command value T20* to limit the regenerative power generation of the electric generator 31 or to disable the regenerative drive of the electric generator 31. Based on this final torque command value T20*, the MGECU 62 controls the electric generator 31 to limit the regenerative power generation of the electric generator 31 or to disable the regenerative drive of the electric generator 31 itself, thus suppressing overcharging of the electric generator 31. As a result, the worst-case scenario described above can be avoided in the battery 33.

[0058] Furthermore, the brake ECU 61 monitors the operation of the braking devices 41 to 44. In this embodiment, the brake ECU 61 functions as an anomaly detection unit that detects abnormalities in the electric generator 31. When the brake ECU 61 detects an anomaly in the braking devices 41 to 44, it disables the operation of the braking devices 41 to 44 and sends an anomaly detection notification to the EVECU 60. Upon receiving the anomaly detection notification from the brake ECU 61, the EVECU 60 performs regenerative torque correction control, which increases the regenerative torque of the electric generator 31 when the vehicle 10 decelerates.

[0059] More specifically, when the braking devices 41-44 are functioning normally and the brake pedal is not depressed, the torque command value adjustment unit 601 of the EVECU 60 sets the basic torque command value T10* to the final torque command value T20*. As described above, based on Figure 4The mapping shown calculates the basic torque command value T10* based on the accelerator pedal input (AP), shift position (SP), and vehicle speed (VC). This is achieved through a mapping based on... Figure 4 The mapping shown is used to set the basic torque command value T10*, for example, when the accelerator pedal operation amount AP is "0", that is, when the vehicle is decelerating at speed 10. Figure 5 The final torque command value T20* is set as shown by the solid line in the middle. As a result, the regenerative torque of the electric generator 31 is determined according to the vehicle speed VC, as shown in the figure. Figure 5 The change is as shown by the solid line. Hereafter, for convenience, [the following will be...] Figure 5 The regenerative torque of the electric generator 31 shown by the solid line is called the "normal regenerative torque TBa". The normal regenerative torque TBa is, for example, a deceleration torque equivalent to "-0.2 G".

[0060] On the other hand, when the braking devices 41 to 44 are malfunctioning, the torque command value adjustment unit 601 of the EVECU 60 corrects the final torque command value T20* in a way that allows the vehicle 10 to decelerate or stop via regenerative braking from the electric generator 31. For example, when the accelerator pedal operation amount AP is "0", the torque command value adjustment unit 601 sets the final torque command value T20* to... Figure 5 The non-time regenerative torque TBb is indicated by a single-dotted line. The non-time regenerative torque TBb is a regenerative torque larger than the normal regenerative torque TBa, for example, the maximum value of the regenerative torque that can be set in the electric generator 31. The non-time regenerative torque TBb is, for example, equivalent to a deceleration torque of "-0.4 [G]". By setting the final torque command value T20* to the non-time regenerative torque TBb, the regenerative torque of the electric generator 31 increases. Therefore, even assuming situations where the braking force applied to the wheels 11-14 from the braking devices 41-44 is insufficient due to malfunctions, or where braking force cannot be applied to the wheels 11-14 from the braking devices 41-44, the vehicle 10 can be decelerated or stopped more reliably.

[0061] Furthermore, in order to avoid overcharging of the battery 33 and thus limit the amount of charge requested by the BMU 63 from the EVECU 60, the EVECU 60 may be unable to perform regenerative torque correction control such as increasing the regenerative power generation of the electric generator 31, or may impose significant restrictions on the execution of regenerative torque correction control. Therefore, adverse situations such as the vehicle 10 not being able to decelerate properly may occur.

[0062] On the other hand, there is a certain grace period from the time when battery 33 becomes overcharged until the worst-case scenario occurs. In other words, if this grace period is within which the worst-case scenario occurs, the probability of battery 33 experiencing a worst-case scenario is low, even if the electric generator 31 is regeneratively driven. Therefore, in this embodiment, when a malfunction occurs in braking devices 41-44, the EVECU 60, during the period from the time the malfunction is detected until a predetermined time has elapsed, enables the electric generator 31 to regenerate while avoiding limiting the charging amount of battery 33 based on requests from the BMU 63.

[0063] Next, refer to Figure 6 and Figure 7 The specific steps of the processing performed by the EVECU 60 are explained below. Furthermore, the EVECU 60 executes these steps repeatedly at a predetermined cycle. Figure 6 The processing is shown. Additionally, in Figure 6 and Figure 7 The initial value of the mandatory stop sign XFE used in the processing is set to "0".

[0064] like Figure 6 As shown, the torque command value adjustment unit 601 of the EVECU 60 first sets the final torque command value T20* as part of step S10. Specifically, when the braking devices 41 to 44 are functioning normally, the torque command value adjustment unit 601 sets the final torque command value T20* based on either the basic torque command value T10* or the braking torque command value T30*. Thus, for example, when the accelerator pedal operation amount AP is "0", the final torque command value T20* is set to... Figure 5 The solid line represents the normal regenerative torque TBa. On the other hand, in the event of an malfunction in the braking devices 41-44, the torque command value adjustment unit 601 corrects the final torque command value T20* by increasing the regenerative torque of the electric generator 31. For example, the torque command value adjustment unit 601 sets the final torque command value T20* to... Figure 5 The non-real-time regenerative torque TBb is shown by the single-dotted line.

[0065] As a follow-up to step S10, step S11 involves the EVECU 60 determining whether the brake malfunction flag XFB is set to "1". When the braking devices 41-44 are functioning normally, the brake ECU 61 sends the brake malfunction flag XFB, set to "0", to the EVECU 60. When a malfunction occurs in the braking devices 41-44, the brake ECU 61 sends the brake malfunction flag XFB, set to "1", to the EVECU 60. The EVECU 60 executes step S11 based on the brake malfunction flag XFB sent from the brake ECU 61.

[0066] Specifically, when the brake malfunction indicator XFB is "0", meaning the braking devices 41-44 are functioning normally, the EVECU 60 performs a negative check in step S11. In this case, the EVECU 60 sets the limit recovery counter C to "0" as part of step S20, and checks whether a limit on the charge amount of battery 33 has been requested from the BMU 63 as part of step S21. If the EVECU 60 performs a negative check in step S21, meaning no limit on the charge amount of battery 33 has been requested from the BMU 63, the process temporarily terminates. Figure 6 The process is shown below. In this case, the torque corresponding to the basic torque command value T10* or the braking torque command value T30* is output from the electric generator 31.

[0067] If the EVECU 60 makes a positive determination in step S21, that is, if a charge limit for the battery 33 is requested from the BMU 63, then as part of step S22, the torque command value adjustment unit 601 of the EVECU 60 determines whether the final torque command value T20* set in step S10 is smaller than the limit torque command value TWin. The limit torque command value TWin is a limit value set for the regenerative torque of the electric generator 31 to prevent overcharging of the battery 33 when a charge limit request is made to the EVECU 60 from the BMU 63. The limit torque command value TWin is preset and stored in the ROM of the EVECU 60. For example, the limit torque command value TWin is set to "0". If the torque command value adjustment unit 601 makes a positive determination in step S22, that is, if the final torque command value T20* is smaller than the limit torque command value Windin, then as part of step S23, after setting the final torque command value T20* to the limit torque command value Windin, the process proceeds to step S30. In this case, either the regenerative torque corresponding to the limit torque command value Windin is output from the electric generator 31, or no regenerative torque is output from the electric generator 31. As a result, since the regenerative power generation of the electric generator 31 is limited, overcharging of the battery 33 can be suppressed.

[0068] If the torque command value adjustment unit 601 makes a negative judgment in step S22, that is, if the final torque command value T20* is higher than or equal to the limit torque command value TWin, then the process in step S23 is not executed and the process proceeds to step S30. In this case, since it is not necessary to limit the torque of the electric generator 31, the torque corresponding to the basic torque command value T10* or the braking torque command value T30* is output from the electric generator 31.

[0069] As part of step S30, EVECU 60 performs fail-safe control. The fail-safe control process is as follows: Figure 7 As shown.

[0070] like Figure 6 As shown, as part of step S31, the EVECU 60 determines whether the brake malfunction flag XFB is "1". Figure 6 If, after a negative check is performed in step S11, step S30 is executed, the brake malfunction flag XFB is set to "0". Therefore, in this case, the EVECU 60 performs a negative check in step S31. Therefore, the EVECU 60... Figure 7 After the control shown ends, temporarily terminate. Figure 6 The processing shown.

[0071] On the other hand, if the EVECU 60 makes a positive judgment in step S11, that is, if the brake abnormality flag XFB is "1", it determines that the braking devices 41 to 44 have malfunctioned. In this case, as part of step S12, the EVECU 60 increments the value of the limit recovery counter C. As part of step S13 following step S12, the EVECU 60 determines whether the value of the limit recovery counter C is greater than or equal to a first predetermined value Cth11. In this embodiment, the grace period TG from the time when the battery 33 becomes overcharged until the worst-case abnormality occurs is determined in advance through experiments, etc. When a time shorter than the grace period TG is set as the parking determination time T11, the first predetermined value Cth11 is set to a value that can determine whether the parking determination time T11 has elapsed since the time when the abnormality of the braking devices 41 to 44 was detected, and is stored in advance in the ROM of the EVECU 60. The parking determination time T11 is a time used to determine whether the period when the vehicle should be forcibly stopped is reached, for example, set to "20 minutes".

[0072] At the initial point in time when an abnormality is detected in braking devices 41-44, the value of the limit recovery counter C is smaller than the first predetermined value Cth11. Therefore, the EVECU 60 makes a negative judgment in the processing of step S13. In this case, as a processing step S14, the EVECU 60 executes power consumption increase control. When the EVECU 60 requests a limit on the charging amount of battery 33 from BMU 63, in order to reduce the charging power of battery 33 which is in a fully charged or near-fully charged state, it executes power consumption increase control to increase the power consumption of electrical loads in vehicle 10 that are the power supply targets of battery 33. For example, the EVECU 60 reduces the charging power of battery 33 by automatically turning on the lights of vehicle 10. Alternatively, the EVECU 60 may also reduce the charging power of battery 33 by intentionally reducing the power efficiency of electric generator 31.

[0073] After performing step S14, EVECU 60 performs step S30 as part of the processing. Figure 7 The fail-safe control is shown. At this time, the brake malfunction indicator XFB is set to "1", and the forced stop indicator XFE is set to "0". Therefore, as... Figure 7 As shown, during step S31, which determines whether the brake malfunction indicator XFB is "1", the EVECU 60 makes an affirmative judgment. Next, during step S32, which determines whether the forced stop indicator XFE is "1", the EVECU 60 makes a negative judgment. As a result, the EVECU 60 terminates. Figure 7 The process shown is temporarily terminated. Figure 6 The processing shown.

[0074] Then, after the stop determination time has elapsed from the point when the abnormality of braking devices 41-44 was detected, EVECU60... Figure 6 In step S13, a positive judgment is made. In this case, as part of step S15, the EVECU 60 determines whether the value of the limit recovery counter C is greater than or equal to a second predetermined value Cth12. The second predetermined value Cth12 is set to a value that can determine whether a predetermined grace period T12 has elapsed since the time point when the abnormality of the braking devices 41 to 44 was detected, and is pre-stored in the ROM of the EVECU 60. The grace period T12 is set, for example, to "30 minutes".

[0075] If the EVECU 60 performs a negative judgment in step S15, that is, if the value of the limit recovery counter C is less than the second predetermined value Cth12, then as part of step S16, the forced stop flag XFE is set to "1", and then the power consumption increase control in step S14 and the fault safety control in step S15 are executed. In this case, as... Figure 7 As shown, the EVECU 60 makes a positive judgment in step S31 and also in step S32. Therefore, as part of step S33, the EVECU 60 performs deceleration control based on the accelerator pedal input amount AP to force the vehicle 10 to a stop. Specifically, the EVECU 60 has the following... Figure 8 The diagram shown represents the mapping between the accelerator pedal input AP and the final torque command value T20*, based on... Figure 8 The mapping shown calculates the final torque command value T20* based on the accelerator pedal input AP. Figure 8 In the mapping shown, when the accelerator pedal operation amount AP is near "0", i.e., when the accelerator pedal is not depressed, the final torque command value T20* is set to "-Ta". Furthermore, when the accelerator pedal operation amount AP is a predetermined value AP11 or higher, i.e., when the accelerator pedal is depressed, the final torque command value T20* is set to "-Tb", which is greater than "-Ta". "-Ta" is, for example, the maximum value of the regenerative torque that can be set in the electric generator 31. "-Ta" is, for example, equivalent to a deceleration torque of "-0.4 [G]". "-Tb" is, for example, equivalent to a deceleration torque of "-0.2 [G]".

[0076] By based on Figure 8 The mapping shown is used to set the final torque command value T20*, and the output torque of the electric generator 31 is set to a negative value regardless of the amount of accelerator pedal operation AP. That is, since regenerative torque is output from the electric generator 31, the vehicle 10 can be forcibly stopped by applying braking force to the drive wheels 13 and 14.

[0077] like Figure 7 As shown, in step S34 following step S33, the EVECU 60 notifies both the passengers inside and outside the vehicle via the drive notification device 55. Through this notification, passengers in the vehicle 10 and people outside the vehicle are aware that the vehicle 10 is about to make an emergency stop. After executing step S34, the EVECU 60 terminates the process. Figure 7 The process shown is temporarily terminated. Figure 6 The processing shown.

[0078] Thus, even when the brake malfunction flag XFB is "1" in this embodiment, i.e., when a malfunction occurs in the braking devices 41 to 44, the EVECU 60 does not perform the processing steps S21 to S23, i.e., the processing to restrict the regenerative drive of the electric generator 31, during the period from the time the malfunction is detected until the grace period TG has elapsed. In other words, during the period from the time the malfunction of the braking devices 41 to 44 is detected until the grace period TG has elapsed, the EVECU 60 controls the electric generator 31 in a manner that generates the emergency regenerative torque TBb while ignoring the restriction request from the BMU 63.

[0079] Then, after a grace period has elapsed since the abnormality of braking devices 41-44 was detected, EVECU 60... Figure 6 In step S15, a positive judgment is made. In this case, EVECU 60 executes steps S21 to S23. As a result, when a limit on the charging amount of battery 33 is requested from BMU 63, the regenerative power generation of electric generator 31 can be limited and overcharging of battery 33 can be suppressed by limiting the final torque command value T20* to the limit torque command value TWin.

[0080] Next, refer to Figure 9 An example of the operation of the vehicle 10 in this embodiment will be explained.

[0081] like Figure 9 As shown in (A), when the SOC value of battery 33 is above the specified value Sth11, BMU 63 requests EVECU 60 to limit the charging amount of battery 33. Therefore, when the final torque command value T20* is less than the limit torque command value TWin, EVECU 60 limits the final torque command value T20* to the limit torque command value TWin. Therefore, as Figure 9 As shown in (B), by setting the accelerator pedal operation amount AP to "0" at time t10, even in cases such as Figure 9 As shown by a single-dotted line in (E), when the final torque command value T20* was originally set to a negative value "-Ta", it is now restricted to the limit torque command value TWin. Furthermore, in Figure 9 The example shown illustrates the case where the torque limiting command value TWin is set to "0". Thus, by setting the torque limiting command value TWin to "0", as... Figure 9 As shown in (F), the lower limit value of the duty cycle of the electric generator 31, DMmin, is limited to "0%". Therefore, the electric generator 31 will not regenerate.

[0082] Thus, by limiting the final torque command value T20* to the limited torque command value TWin, the braking force acting on drive wheels 13 and 14 is reduced. EVECU 60 requests brake ECU 61 to output this reduced braking force from braking devices 41 to 44. As a result, as Figure 9 As shown in (D), braking force is applied to vehicle 10, thus enabling vehicle 10 to decelerate.

[0083] After that, as Figure 9 As shown in (B), if the accelerator pedal is depressed at time t11, the charging power of the battery 33 will be consumed due to the drive of the electric generator 31. Therefore, as Figure 9 As shown in (A), the SOC value of battery 33 decreases. Accompanying this, when the torque limiting command value Twin is eased, as... Figure 9 As shown in (F), the lower limit value DMmin of the duty cycle of the electric generator 31 is also mitigated.

[0084] Under such circumstances, if at least one of the braking devices 41-44 malfunctions at time t12, then as follows Figure 9 As shown in (E), the EVECU 60 sets the final torque command value T20* to the emergency regenerative torque TBb. Assuming the emergency regenerative torque TBb is set to the maximum value "-Ta" of the regenerative torque that can be set in the electric generator 31, then as... Figure 9 As shown in (F), the lower limit value DMmin of the duty cycle of the electric generator 31 is set to "-100 (%)". Therefore, the limitation on the regenerative power generation of the electric generator 31 is essentially lifted. Consequently, since the electric generator 31 operates in regenerative drive mode, braking force is applied to the drive wheels 13 and 14. Therefore, even in the event of an abnormality in the braking devices 41 to 44, such as... Figure 9 As shown in (D), braking force is also applied to vehicle 10.

[0085] In addition, such as Figure 9 As shown in (G), if at least one of the braking devices 41 to 44 malfunctions at time t12, the value of the limit recovery counter C increases over time starting from that point in time.

[0086] After time t12, such as Figure 9 As shown in (B), for example, when the accelerator pedal is pressed at time t13, as Figure 9 As shown in (E), the final torque command value T20* is set to a positive value based on the accelerator pedal operation amount AP. Therefore, drive torque is output from the electric generator 31, thus, as... Figure 9As shown in (C), vehicle 10 accelerates at time t13. Subsequently, when the accelerator pedal is depressed, vehicle 10 accelerates by outputting a drive torque corresponding to the accelerator pedal operation amount AP from the electric generator 31. Conversely, when the accelerator pedal operation amount AP is "0", vehicle 10 decelerates by outputting a temporary regenerative torque TBb from the electric generator 31.

[0087] After that, as Figure 9 As shown in (B), after the driver presses the accelerator pedal at time t14, at time t15, as... Figure 9 As shown in (G), the value of the limit recovery counter C reaches the first predetermined value Cth11. That is, at time t15, the stop determination time T11 has elapsed since the abnormality of braking devices 41-44 was detected. In this case, EVECU 60 executes... Figure 7 The processing of steps S33 and S34 is shown. That is, at time t15, EVECU 60 begins control to forcibly stop vehicle 10 and notifies both the inside and outside of the vehicle. Thus, as Figure 9 As shown in (E), regardless of the value of the accelerator pedal operation AP, the final torque command value T20* is set to a negative value. Therefore, as Figure 9 As shown in (C), it can more reliably decelerate vehicle 10.

[0088] In addition, such as Figure 8 As shown, the final torque command value T20* varies according to the amount of accelerator pedal operation AP. Therefore, as Figure 9 As shown in (B), when the accelerator pedal is depressed at time t16, as Figure 9 As shown in (E), the final torque command value T20* increases. That is, the regenerative torque of the electric generator 31 decreases. Thus, even when the vehicle 10 is forcibly stopped, the vehicle 10 can still operate in accordance with the driver's intention.

[0089] Subsequently, at time t17, the value of the limit recovery counter C reaches the second predetermined value Cth12. That is, at time t17, a grace period TG has elapsed since the time point when the abnormality of braking devices 41-44 was detected. At this time, as Figure 9 As shown in (E), the EVECU 60 sets the final torque command value T20* to the limit torque command value Twin, i.e., "0", so the electric generator 31 no longer regenerates power. Therefore, after time t17, overcharging of the battery 33 is suppressed, thus preventing the worst-case scenario of battery 33 from occurring.

[0090] According to the above description, the control device 80 of the vehicle 10 of this embodiment can achieve the following functions and effects (1) to (4).

[0091] (1) When the brake ECU 61 detects an abnormality in the braking devices 41 to 44, the EVECU 60, during the period from the time the abnormality is detected until the specified grace period TG has elapsed, regenerates the electric generator 31 by generating an extraordinary regenerative torque TBb that is greater than the normal regenerative torque TBa, regardless of the state of charge of the battery 33. The battery 33 does not immediately cause an abnormality at the point of overcharging; in fact, there is a certain degree of grace period from when it becomes overcharged until the worst-case abnormality occurs. Therefore, if the electric motor is regeneratively driven during the period from the time the abnormality is detected until the specified grace period TG has elapsed when the abnormality in the braking devices 41 to 44 is detected, braking force can be obtained while preventing the worst-case abnormality of the battery 33, even assuming the battery 33 is overcharged. Therefore, the vehicle 10 can be stopped.

[0092] (2) When the EVECU 60 detects an abnormality in the braking devices 41 to 44 and a stop determination time T11 has elapsed, it causes the electric generator 31 to regenerate and drive the vehicle 10 to automatically decelerate and stop. According to this structure, the vehicle 10 can be stopped before the worst abnormality of the battery 33 occurs, thus ensuring the safety of the vehicle 10.

[0093] (3) EVECU 60 usage Figure 8 The mapping shown calculates the final torque command value T20* based on the accelerator pedal operation amount AP, thereby setting the deceleration of vehicle 10 based on the accelerator pedal operation amount AP. According to this structure, the deceleration of vehicle 10 corresponding to the driver's driving operation can be achieved, thus improving driving performance.

[0094] (4) During the period from the point when the abnormality of the braking devices 41 to 44 is detected until the grace period TG has elapsed, the EVECU 60 increases the power consumption of the electrical load, which is the power supply target of the battery 33. According to this structure, overcharging of the battery 33 can be avoided more reliably.

[0095] <Second Implementation>

[0096] Next, the control device 80 of the second embodiment will be described. Hereinafter, the description will focus on the differences between the control device 80 of the first embodiment and the control device 80 of the first embodiment.

[0097] like Figure 10 As shown, in step S12 of this embodiment, the EVECU 60 calculates the current limit recovery counter C by adding a predetermined value ΔC to the value of the previous limit recovery counter C.

[0098] Specifically, EVECU 60 uses Figure 11 The mapping shown represents the relationship between the charging current value Ib of battery 33 and a predetermined value ΔC, and the predetermined value ΔC is calculated based on the charging current value Ib. The charging current value Ib of battery 33 is the current supplied to battery 33 for charging battery 33 through the regenerative drive of electric generator 31. Therefore, the greater the power used to charge battery 33, the greater the charging current value of battery 33. In this embodiment, the charging current value of battery 33 is equivalent to the regenerative power generated by the regenerative drive of electric generator 31. In addition, EVECU 60 obtains information about the charging current value Ib of battery 33 from BMU 63.

[0099] EVECU 60 based on Figure 11 The mapping shown is used to calculate the specified value ΔC. Then, the current limit recovery counter C is obtained by adding the specified value ΔC to the previous limit recovery counter C. Therefore, the limit recovery counter C is as follows: Figure 9 The changes are as shown by the double-dotted line in (G).

[0100] exist Figure 11 In the mapping shown, the larger the charging current value of battery 33, the larger the specified value ΔC. Therefore, after the braking devices 41-44 detect an abnormality, the larger the charging current value of battery 33, the earlier the period for making a positive judgment in steps S13 and S15—in other words, the period when the forced stop of vehicle 10 is executed and the period when the regenerative power generation of electric generator 31 is limited. As a result, the larger the charging current value of battery 33, the shorter the stop determination time T11 and the grace period TG.

[0101] According to the control device 80 of the vehicle 10 described above, the following (5) functions and effects can be obtained.

[0102] (5) After the EVECU 60 detects an abnormality in the braking devices 41 to 44, it changes the stop determination time T11 and the grace time TG based on the charging current value of the electric generator 31. According to this structure, the stop determination time T11 and the grace time TG can be set according to the actual situation of the regenerative power generated by the electric generator 31, so that the forced stopping of the vehicle 10 and the limitation of the regenerative power generation of the electric generator 31 can be performed more appropriately.

[0103] <Third Implementation Method>

[0104] Next, the control device 80 of the third embodiment will be described. Hereinafter, the description will focus on the differences from the control device 80 of the first embodiment.

[0105] like Figure 12 As shown, as a step S40 following step S14, the EVECU 60 of this embodiment performs the setting process for the final torque command value T20*. Specifically, as... Figure 13 As shown, as part of step S41, the EVECU 60 first sets the torque limiting command value TWin. The EVECU 60 has the following... Figure 14 The diagram shows the mapping between the value of the limit recovery counter C and the coefficient Kwin. As described above, since the limit recovery counter C increases from the time point when the abnormality of the braking devices 41 to 44 is detected, the elapsed time from that time point is shown. Therefore, Figure 14 The mapping shown corresponds to a mapping representing the relationship between the elapsed time from the point when the abnormality of braking devices 41-44 was detected and the coefficient Kwin. For example... Figure 14 As shown, the longer the elapsed time from the point when the abnormality of braking devices 41 to 44 is detected, the smaller the coefficient Kwin is set to.

[0106] EVECU 60 in use Figure 14 After calculating the coefficient Kwin using the mapping shown, the limiting torque command value TWin is calculated based on the following equation f1, according to the maximum regenerative torque TWinMax and the coefficient Kwin. The maximum regenerative torque TWinMax is the maximum value of the regenerative torque of the electric generator 31, for example, it is equivalent to a deceleration torque of "-0.4 [G]".

[0107] Twin = Kwin × TWinMax(f1)

[0108] By setting the limiting torque command value TWin based on the formula f1, the longer the elapsed time from the time point when the abnormality of the braking device 41 to 44 is detected, the closer the limiting torque command value TWin is to "0" from the maximum value of the regenerative torque TWinMax.

[0109] like Figure 13 As shown, in step S42 following step S41, the torque command value adjustment unit 601 of the EVECU 60 determines whether the final torque command value T20* set in step S10 is smaller than the limit torque command value TWin. If the torque command value adjustment unit 601 makes an affirmative determination in step S42, that is, if the final torque command value T20* is smaller than the limit torque command value TWin, then in step S43, the final torque command value T20* is set to the limit torque command value TWin, and the process returns to... Figure 12The processing is shown below. Therefore, the longer the time elapsed since the abnormality of the braking devices 41 to 44 was detected, the closer the final torque command value T20* will be to "0" from the maximum value of the regenerative torque TWinMax; in other words, the regenerative torque will change from its maximum state to "0".

[0110] On the other hand, if the torque command value adjustment unit 601 makes a negative judgment in the processing of step S42, it will not execute the processing of step S43 but will return to the previous step. Figure 12 The processing shown.

[0111] According to the control device 80 of the vehicle 10 described above, the following (6) functions and effects can be obtained.

[0112] (6) The EVECU 60 adjusts the regenerative torque of the electric generator 31 based on the elapsed time since the detection of the abnormality of the braking devices 41 to 44. According to this structure, the longer the elapsed time since the detection of the abnormality of the braking devices 41 to 44, the more the regenerative power generation of the electric generator 31 can be reduced, and thus, overcharging of the electric generator 31 can be more reliably avoided.

[0113] <Other Implementation Methods>

[0114] Alternatively, each implementation method can be carried out in the following ways.

[0115] ·replace Figure 14 As shown in the mapping, the EVECU 60 of the third embodiment can also use a mapping that represents the relationship between the charging current value Ib of the battery 33 and the coefficient Kwin. Therefore, the EVECU 60 can change the regenerative torque of the electric generator 31 based on the regenerative power generated by the electric generator 31. Even with this structure, the same or similar effects as those shown in (6) above can be obtained.

[0116] • The structure of the control device 80 in each embodiment is not limited to the electric vehicle 10, and can also be applied to the mobility of any mobile body powered by an electric motor, such as a vertical take-off and landing machine that moves in the air.

[0117] The control device 80 and its control method described in this disclosure can also be implemented by one or more dedicated computers, which are provided by comprising a processor and a memory, the processor being programmed to perform one or more functions embodied in a computer program. Alternatively, the control device 80 and its control method described in this disclosure can be implemented by a dedicated computer, which is provided by comprising a processor including one or more dedicated hardware logic circuits. Alternatively, the control device 80 and its control method described in this disclosure can be implemented by one or more dedicated computers, which are composed of a processor and a memory programmed to perform one or more functions, and a processor including one or more hardware logic circuits. The computer program can also be stored in a computer-readable non-transitory tangible storage medium as instructions to be executed by a computer. The dedicated hardware logic circuits and hardware logic circuits can also be implemented by digital circuits or analog circuits including multiple logic circuits.

[0118] This disclosure is not limited to the specific examples described above. Even if those skilled in the art make appropriate design changes to the specific examples described above, as long as they include the features of this disclosure, they are included within the scope of this disclosure. The elements included in the above specific examples, as well as their configurations, conditions, shapes, etc., are not limited to the illustrated cases and can be appropriately modified. As long as no technical contradiction arises, the elements included in the above specific examples can be appropriately combined and changed.

Claims

1. A control device for a mobile body, the control device being disposed on the mobile body, the mobile body comprising: an electric motor operating as a power source for movement; and a battery for supplying power to the electric motor and generating electricity through regenerative braking of the electric motor, the mobile body being capable of obtaining braking force through regenerative braking of the electric motor and operation of a braking device. The control device for the moving body includes: An anomaly detection unit is provided to detect anomalies in the braking device. as well as An electric motor control unit that controls the electric motor. When the regenerative torque generated by the regenerative drive of the electric motor when the braking device is in normal operation is set as the normal regenerative torque, When the abnormality detection unit detects an abnormality in the braking device, the motor control unit, during the period from the time of abnormality detection until a predetermined grace period has elapsed, regenerates the motor to generate an extraordinary regenerative torque that is greater than the normal regenerative torque, regardless of the battery's state of charge. When a time shorter than the grace period is set as the parking determination time... When the stop determination time has elapsed since the time point from which the abnormality of the braking device was detected, the motor control unit decelerates and stops the moving body. The motor control unit changes the stop determination time based on the regenerative power generated by the regenerative drive of the motor after the abnormality of the braking device is detected.

2. The control device for the moving body as described in claim 1, characterized in that, The motor control unit adjusts the regenerative torque of the motor based on the elapsed time since the abnormality of the braking device was detected or the regenerative power generated by the motor.

3. The control device for a moving body as described in claim 1, characterized in that, The control device further includes a throttle position detection unit for detecting the amount of throttle pedal operation of the moving body. The motor control unit sets the deceleration of the moving body based on the amount of accelerator pedal operation detected by the accelerator position detection unit.

4. The control device for a moving body as described in any one of claims 1 to 3, characterized in that, It also includes a battery control unit for controlling the battery. When the battery control unit determines that the battery may be in an overcharged state, it requests the motor control unit to limit the regenerative drive from the motor to the battery. During the period from the time when the abnormality of the braking device is detected until the grace period has elapsed, the motor control unit ignores the request from the battery control unit and controls the motor in a manner that generates the emergency regenerative torque.

5. The control device for a moving body as described in claim 4, characterized in that, The motor control unit adjusts the grace period based on the regenerative power generated by the regenerative drive of the motor after the abnormality of the braking device is detected.

6. The control device for a moving body as described in any one of claims 1 to 5, characterized in that, During the period from the time when the abnormality of the braking device is detected until the grace period has elapsed, the motor control unit increases the power consumption of the electrical load, which is the power supply target of the battery.

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