Vehicle control device

Abstract

To provide a control device of a movable body which can more smoothly stop a movable body.SOLUTION: A travel control ECU 50 comprises: a switching control unit 55; and a deviation acquisition unit 64. The switching control unit 55 executes switching control of increasing a braking torque of a braking device while reducing a braking torque of MGs 11a, 11b when decelerating a vehicle 10. The deviation acquisition unit 64 acquires a gradient correction torque Tslp indicating a deviation between the braking torque of the braking device and a braking torque required for keeping the vehicle in the stop state when the vehicle is in the stop state. The switching control unit 55 corrects an output torque of the MGs 11a, 11b on the basis of the gradient correction torque Tslp after it is detected that the vehicle is in the stop state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a control device for a vehicle. [Background technology]

[0002] A conventional vehicle control device is described in Patent Document 1 below. This vehicle is equipped with a rotating electric machine that functions as a generator and is capable of generating braking torque from regenerative torque, and a brake control device that electrically controls braking torque of mechanical brakes provided on the wheels. This control device performs switching control to switch between braking torque by the rotating electric machine and braking torque by the mechanical brakes while maintaining a target braking torque.

[0003] Specifically, the control device initiates switching control when the vehicle speed decreases to a predetermined switching start speed after the vehicle starts decelerating based on the braking torque of the rotating electric machine. Thereafter, during the period from when the vehicle speed decreases from the switching start speed to when the switching end speed, the control device reduces the braking torque of the rotating electric machine and increases the braking torque of the mechanical brake while maintaining the total torque, which is the sum of the braking torque of the rotating electric machine and the braking torque of the mechanical brake, at a target braking torque. When the vehicle speed reaches the switching end speed, switching from the braking torque of the rotating electric machine to the braking torque of the mechanical brake is completed. If the braking torque of the vehicle deviates from the target braking torque during switching control, i.e., during the transition from the braking torque of the rotating electric machine to the braking torque of the mechanical brake, the control device corrects the braking torque of the rotating electric machine to reduce the deviation. The control device calculates the braking torque of the vehicle based on the estimated road resistance, coasting torque, vehicle acceleration, differential gear ratio, tire diameter, and reference vehicle weight. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-56587 Summary of the Invention [Problem to be solved by the invention]

[0005] In the vehicle control device described in Patent Document 1, if the vehicle acceleration changes significantly during switching control, for example, the calculated value of the vehicle's braking torque changes suddenly, resulting in a large change in the correction amount of the braking torque of the rotating electric machine. For example, if the vehicle runs over a curb during switching control, or if the road surface on which the vehicle is traveling changes from a flat surface to an inclined surface, the vehicle acceleration may change significantly, resulting in a large change in the correction amount of the braking torque of the rotating electric machine. In such cases, the control torque of the rotating electric machine changes suddenly, making it impossible to stop the vehicle smoothly. This is a factor that deteriorates the ride comfort of the vehicle.

[0006] The present disclosure has been made in consideration of the above circumstances, and has an object to provide a control device for a moving body that can stop the moving body more smoothly. [Means for solving the problem]

[0007] A control device (50) that solves the above problem is mounted on a vehicle (10) having braking devices (16a-16d) capable of applying braking torque to wheels (18a-18d) and rotating electric machines (11a, 11b) capable of applying braking torque to the wheels by regenerative operation. The control device includes a switching control unit (55), an information acquisition unit (51), and a deviation acquisition unit (64). The switching control unit executes switching control to reduce the braking torque of the rotating electric machine while increasing the braking torque of the braking device when decelerating the vehicle. The information acquisition unit acquires information on the state of the vehicle. When the vehicle comes to a stop, the deviation acquisition unit acquires a braking torque deviation indicating the deviation between the braking torque required to maintain the vehicle in a stopped state and the braking torque of the braking device. After the information acquisition unit detects that the vehicle has come to a stop, the switching control unit corrects the output torque of the rotating electric machine based on the braking torque deviation.

[0008] According to this configuration, after the vehicle comes to a stop, a braking torque corresponding to the braking torque deviation is output from the rotating electric machine. That is, a torque corresponding to the deviation between the braking torque required to keep the vehicle stopped and the braking torque of the braking device is output from the rotating electric machine. By outputting a torque corresponding to the deviation in the braking torque of the braking device from the rotating electric machine in this way, a sudden change in the output torque of the rotating electric machine is suppressed, and a situation in which the vehicle's braking force is insufficient is less likely to occur. This makes it possible to stop the vehicle more smoothly.

[0009] The symbols in parentheses in the above means and claims are examples showing the correspondence with specific means described in the embodiments to be described later. [Effects of the Invention]

[0010] According to the control device for a moving body of the present disclosure, it is possible to stop the moving body more smoothly. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing a schematic configuration of a vehicle according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing a schematic configuration of the brake system according to the embodiment. [Figure 3] FIG. 3 is a block diagram showing the electrical configuration of the vehicle according to the embodiment. [Figure 4] FIG. 4 is a flowchart showing the procedure of the process executed by the cruise control ECU of the embodiment. [Figure 5] FIG. 5 is a flowchart showing the procedure of the deviation ratio calculation process executed by the cruise control ECU of the embodiment. [Figure 6] FIG. 6 is a flowchart showing the procedure of the process executed by the cruise control ECU of the embodiment. [Figure 7]7A to 7F are timing charts showing the transitions of the basic braking torque, vehicle speed, regenerative torque request value, MG output torque, braking torque request value, and braking torque of the braking device in the vehicle of the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, an embodiment of a vehicle control device will be described with reference to the drawings. To facilitate understanding of the description, the same components in the drawings will be denoted by the same reference numerals as much as possible, and duplicate descriptions will be omitted. First, a schematic configuration of a vehicle equipped with a control device of this embodiment will be described. As shown in Fig. 1, a vehicle 10 includes a front MG (Motor Generator) 11a, a rear MG 11b, a front inverter device 12a, a rear inverter device 12b, and a battery 13. The vehicle 10 is a so-called electric vehicle that runs on the power of the MGs 11a and 11b. In this embodiment, the vehicle 10 corresponds to a moving body.

[0013] The inverter devices 12a and 12b convert the DC power stored in the battery 13 into AC power, and supply the converted AC power to the MGs 11a and 11b, respectively. The MGs 11a and 11b are rotating electric machines that operate as electric motors and generators. When operating as electric motors, the MGs 11a and 11b are driven by AC power supplied from the inverter devices 12a and 12b, respectively. In the vehicle 10, the driving force of the front MG 11a is transmitted to the right front wheel 18a and the left front wheel 18b via the front drive train 14a and the front drive shaft 15a, respectively, thereby rotating the front wheels 18a and 18b. Similarly, the driving force of the rear MG 11b is transmitted to the right rear wheel 18c and the left rear wheel 18d via the rear drive train 14b and the rear drive shaft 15b, respectively, thereby rotating the rear wheels 18c and 18d. In this way, the vehicle 10 is a so-called four-wheel drive vehicle in which the four wheels 18a to 18d function as drive wheels.

[0014] The MGs 11a and 11b operate as generators by performing regenerative operation when braking the vehicle 10. Specifically, when braking the vehicle 10, braking torque applied to the right front wheel 18a and the left front wheel 18b is input to the front MG 11a via the front drive shaft 15a and the front drive train 14a. The front MG 11a generates electricity based on the torque input inversely from the front wheels 18a and 18b. The AC power generated by the front MG 11a is converted to DC power by the front inverter device 12a and charged into the battery 13. Similarly, the AC power generated by the rear MG 11b is converted to DC power by the rear inverter device 12b and charged into the battery 13.

[0015] Braking devices 16a to 16d are provided on the four wheels 18a to 18d, respectively. The braking devices 16a to 16d are components of a hydraulic braking system 20 shown in Fig. 2. The hydraulic braking system 20 applies a braking force to the vehicle 10 by actuating the braking devices 16a to 16d based on the driver's depression of a brake pedal 21 to apply a frictional force to the wheels 18a to 18d.

[0016] Specifically, as shown in FIG. 2, the hydraulic braking system 20 includes a brake pedal 21, a master cylinder 22, a booster 23, a reservoir tank 24, a hydraulic circuit 25, and braking devices 16a to 16d. The master cylinder 22 generates hydraulic pressure in the brake oil based on the driver's depression of the brake pedal 21. A booster 23 is connected to the brake pedal 21. The master cylinder 22 is fixed to the booster 23. The booster 23 converts the pressure input to the brake pedal 21 by the driver's depression into brake hydraulic pressure corresponding to the amount of operation of the brake pedal 21. In this embodiment, the brake hydraulic pressure in the master cylinder 22 is also referred to as master cylinder pressure. A master cylinder pump (not shown) is provided in the master cylinder 22, and this pump pressurizes the master cylinder 22, making it possible to adjust the master cylinder pressure. A reservoir tank 24 is provided above the master cylinder 22. When the brake pedal 21 is released, the master cylinder 22 and the reservoir tank 24 are in communication.

[0017] The hydraulic circuit 25 is provided between the master cylinder 22 and the braking devices 16a to 16d, and is a circuit that adjusts and transmits the hydraulic pressure of the brake oil between the master cylinder 22 and the braking devices 16a to 16d. In this embodiment, the hydraulic pressure of the brake oil corresponds to the fluid pressure. The braking devices 16a to 16d have wheel cylinders 26a to 26d, respectively. The wheel cylinders 26a to 26d apply braking force to the wheels 18a to 18d, respectively, by receiving hydraulic pressure of brake oil transmitted from the hydraulic circuit 25. The braking devices 16a to 16d formed by the wheel cylinders 26a to 26d can be various types of braking devices, such as drum type or disc type.

[0018] The vehicle 10 has various sensors for detecting its state. As shown in Fig. 3, the vehicle 10 has, for example, a master cylinder pressure sensor 30, a wheel pressure sensor 31, wheel speed sensors 32a to 32d, MG resolvers 33a and 33b, current sensors 34a and 34b, an acceleration sensor 35, an accelerator opening sensor 36, and a brake stroke sensor 37.

[0019] The master cylinder pressure sensor 30 detects the master cylinder pressure P mc The wheel pressure sensor 31 detects the wheel pressure P wc The wheel speed sensors 32a to 32d are provided on the four wheels 18a to 18d, respectively, and detect the wheel speed ω wh (a)~ω wh The MG resolvers 33a and 33b are provided on the two MGs 11a and 11b, respectively, and detect the MG rotation speed ω fmg ,ω rmg Current sensors 34a and 34b are also provided in the two MGs 11a and 11b, respectively, and detect the drive current I mg (a),I mg (b) is detected respectively.

[0020] The acceleration sensor 35 is attached to the vehicle body 17 shown in FIG. 1 and detects the acceleration A sen The acceleration sensor 35 is a so-called six-axis acceleration sensor that can detect accelerations in the front-rear, left-right, and up-down directions of the vehicle body 17 as well as the pitch, roll, and yaw directions. The accelerator opening sensor 36 detects the depression amount Sa of the accelerator pedal of the vehicle 10. The brake stroke sensor 37 detects the depression amount Sb of the brake pedal 21 shown in FIG. 2.

[0021] The vehicle 10 is equipped with various ECUs (Electronic Control Units) for controlling a plurality of devices mounted thereon. As shown in Fig. 3, the vehicle 10 is equipped with, for example, a brake ECU 40 and a cruise control ECU 50. Each of the ECUs 40, 50 is mainly configured with a microcomputer having a CPU, ROM, RAM, etc. Each of the ECUs 40, 50 can bidirectionally communicate various information via an in-vehicle network 70 provided in the vehicle 10.

[0022] The brake ECU 40 controls the hydraulic braking system 20 by executing a program pre-stored in its ROM. For example, the brake ECU 40 controls the hydraulic braking system 20 based on a braking torque request value transmitted from the cruise control ECU 50. The braking torque request value is a target value of the braking torque to be applied from the braking devices 16a to 16d to the wheels 18a to 18d. The brake ECU 40 controls the hydraulic braking system 20 so that the sum of the braking torques respectively applied from the braking devices 16a to 16d to the wheels 18a to 18d becomes the braking torque request value.

[0023] The cruise control ECU 50 executes a program pre-stored in its ROM to comprehensively control the traveling of the vehicle 10. In this embodiment, the cruise control ECU 50 corresponds to a control device. The cruise control ECU 50 has, as functional elements realized by executing the program, for example, an information acquisition unit 51, a target torque setting unit 52, an MG control unit 53, and a braking instruction unit 54.

[0024] The information acquisition unit 51 detects and calculates various state quantities of the vehicle 10 based on output signals from sensors mounted on the vehicle 10. For example, the information acquisition unit 51 detects and calculates the master cylinder pressure P mc , wheel pressure P wc , wheel speed ω wh (a)~ω wh (d), MG rotation speed ω fmg ,ω rmg , drive current I mg (a),I mg(b) Acceleration A of vehicle 10 sen , the depression amount Sa of the accelerator pedal, and the depression amount Sb of the brake pedal 21. The information acquisition unit 51 also calculates various state quantities of the vehicle 10 based on the detection values ​​of the sensors. For example, the information acquisition unit 51 calculates the wheel speed ω wh (a)~ω wh (d) is calculated, and the average wheel speed is calculated by using a calculation formula or the like from the calculated average wheel speed. c and the acceleration A of vehicle 10 wh The information acquisition unit 51 also calculates the MG rotation speed ω fmg ,ω rmg By calculating the time differential values ​​of each of the above, the rotational acceleration a of the front MG 11a is calculated. fmg and the rotational acceleration of the rear MG11b a rmg Furthermore, the information acquisition unit 51 acquires the MG rotation speed ω fmg ,ω rmg The average value of ω is calculated and the calculated average value is used to calculate the MG rotation speed ω mg Used as.

[0025] The target torque setting unit 52 acquires various state quantities of the vehicle 10 from the information acquisition unit 51, and based on the acquired state quantities, sets a torque command value T mg * Set. For example, when the target torque setting unit 52 detects that the accelerator pedal is depressed based on the accelerator pedal depression amount Sa acquired from the information acquisition unit 51, the target torque setting unit 52 calculates a basic driving torque based on the accelerator pedal depression amount Sa using an arithmetic expression, a map, or the like. The basic driving torque is a target value of the driving torque to be applied to the wheels 18a to 18d in order to accelerate the vehicle 10. The basic driving torque is set to a positive value when accelerating the vehicle 10 in the forward direction, and is set to a negative value when accelerating the vehicle 10 in the reverse direction. The target torque setting unit 52 calculates, from the calculated basic driving torque, a driving torque request value T drv and the calculated drive torque requirement value T drvThe torque indication value T mg * to the MG control unit 53.

[0026] Furthermore, when the target torque setting unit 52 detects that the brake pedal 21 has been depressed based on the depression amount Sb of the brake pedal 21 acquired from the information acquisition unit 51, the target torque setting unit 52 calculates a basic braking torque based on the depression amount Sb of the brake pedal 21 using an arithmetic expression, a map, or the like. The basic braking torque is a target value of the braking torque to be applied to the wheels 18a to 18d in order to decelerate the vehicle 10. The basic braking torque is basically set to a negative value. From the calculated basic braking torque, the target torque setting unit 52 calculates a regenerative torque request value T rgr The regenerative torque demand value T rgr The torque indication value T mg * to the MG control unit 53.

[0027] The MG control unit 53 receives the torque command value T mg * The drive of the MGs 11a and 11b is controlled based on the torque command value T mg * is the required driving torque T drv When the setting is , the sum of the driving torques of the MGs 11a and 11b is equal to the driving torque requirement value T drv As a result, a driving torque corresponding to the accelerator pedal depression amount Sa is output from the MGs 11a and 11b, and the vehicle 10 accelerates in the forward or backward direction.

[0028] On the other hand, the torque indication value T mg * is the regenerative torque demand value T rgr When the regenerative torque of each of the MGs 11a and 11b is set to , the sum of the regenerative torques of the MGs 11a and 11b is equal to the regenerative torque request value T rgrAs a result, a regenerative torque corresponding to the depression amount Sb of the brake pedal 21 is output from the MGs 11a and 11b, and the vehicle 10 decelerates.

[0029] In the following description, the drive torque and regenerative torque of the MGs 11a and 11b are also collectively referred to as "output torque of the MGs 11a and 11b." Incidentally, if the vehicle 10 could be stopped using only the regenerative torque of the MGs 11a and 11b without using the hydraulic braking system 20 when the vehicle 10 is decelerated and then stopped by the regenerative torque of the MGs 11a and 11b, it would be possible to suppress abnormal noises that occur when the vehicle 10 is stopped and stabilize the behavior of the vehicle 10.

[0030] However, when the vehicle 10 stops on a slope with a predetermined gradient, gravity exerts an external force on the vehicle 10 in the longitudinal direction. Therefore, to maintain the vehicle 10 in a stopped state against gravity, it is necessary to continuously apply braking torque to the wheels 18a-18d. If regenerative torque corresponding to this braking torque continues to be output from the MGs 11a and 11b, heat generation due to motor lock may occur in the MGs 11a and 11b. Furthermore, control restrictions and the like may prevent the MGs 11a and 11b from continuously outputting regenerative torque. Therefore, after the vehicle 10 stops, it is desirable to switch from the regenerative torque of the MGs 11a and 11b to the braking torque of the hydraulic braking system 20. In this embodiment, the stopped state of the vehicle 10 may be either the stopped state of the vehicle 10 or the parked state of the vehicle 10. Furthermore, the stopped state of the vehicle 10 may be either the stopped state of the vehicle 10 or the parking state of the vehicle 10.

[0031] Therefore, the cruise control ECU 50 executes switching control to switch from the regenerative torque of the MGs 11a and 11b to the braking torque of the braking devices 16a to 16d when the vehicle 10 stops on a slope, etc. As shown in Fig. 3, the cruise control ECU 50 further includes a switching control unit 55 that executes this switching control.

[0032] For example, after the vehicle 10 starts to decelerate due to the regenerative operation of the MGs 11a and 11b, the switching control unit 55c The switching control unit 55 monitors the transition of the vehicle speed V c is the desired switching speed V tha Specifically, the switching control unit 55 starts the switching control when it detects that the regenerative torque request value T rgr The absolute value of is gradually decreased over time, and the braking torque requirement value T rb Therefore, after the switching control is started, the braking torque request value T rb The regenerative torque demand value T rgr and braking torque requirement T rb The sum of these torques is maintained at a basic braking torque corresponding to the depression amount of the brake pedal 21. By executing such switching control, the regenerative torque of the MGs 11a and 11b gradually decreases, and the braking torque applied to the wheels 18a to 18d from the hydraulic braking system 20 gradually increases. In the following, the regenerative torque required value T rgr "Basic regenerative torque request value T rgr " is also called.

[0033] On the other hand, the switching control unit 55 calculates the braking torque T required at the time of stopping during the period in which the switching control is being performed. stp Calculate the braking torque required when stopping, T stp is the braking torque to be applied to the wheels 18a to 18d from the hydraulic braking system 20 in order to maintain the stopped state of the vehicle 10 after it has stopped. For example, the switching control unit 55 may be configured to calculate the first deceleration of the vehicle 10 detected based on the output signal of the acceleration sensor 35 and the wheel speed ω wh (a)~ω whThe information acquisition unit 55 acquires from the information acquisition unit 51 the second deceleration of the vehicle 10 detected based on (d). The first deceleration broadly includes the actual deceleration of the vehicle 10 in the vehicle longitudinal direction and the component of gravitational acceleration in the vehicle traveling direction. The second deceleration is the actual deceleration of the vehicle 10 in the vehicle longitudinal direction. Therefore, the difference between the first deceleration and the second deceleration is the vehicle longitudinal direction component of gravitational acceleration. Using this, the switching control unit 55 calculates the difference between the first deceleration and the second deceleration, and calculates the deceleration force, which is the gravitational component acting on the vehicle 10 in the vehicle longitudinal direction when the vehicle 10 stops, by using a predetermined calculation formula or the like from the calculated difference value.

[0034] The switching control unit 55 calculates the braking torque T required at the time of stopping from the calculated deceleration force using a predetermined calculation formula or the like. stp The required braking torque T stp Braking torque requirement T rb When the vehicle 10 stops, the brake ECU 40 transmits the braking torque request value T rb The hydraulic braking system 20 is controlled based on the above. As a result, the braking devices 16a to 16d apply the braking torque T required for stopping to the wheels 18a to 18d. stp Since the vehicle 10 is provided with the brakes, it is possible to maintain the stopped state even when the vehicle 10 is stopped on a slope.

[0035] However, compared with the control accuracy and response accuracy of the regenerative torque of the MGs 11a and 11b, the control accuracy and response accuracy of the braking torque of the hydraulic braking system 20 are low. This is because the braking torque actually applied to the wheels 18a to 18d from the hydraulic braking system 20 is less than the braking torque request value T rb If the absolute value of the braking torque of the hydraulic braking system 20 deviates in a direction that decreases when the vehicle 10 stops on an uphill road, the braking torque of the hydraulic braking system 20 will be insufficient, and the vehicle 10 may slide down after stopping.

[0036] On the other hand, one possible method is to compensate for the deviation in braking torque of the hydraulic braking system 20 by the regenerative torque of the MGs 11a and 11b, but if the regenerative torque of the MGs 11a and 11b is determined based on the acceleration of the vehicle 10 as in the control device described in Patent Document 1, there is a possibility that the regenerative torque of the MGs 11a and 11b will change significantly when there is a sudden change in the acceleration of the vehicle 10. In such a case, a large braking force will be applied to the vehicle 10, which may prevent the vehicle 10 from being stopped smoothly.

[0037] Therefore, the travel control ECU 50 of this embodiment calculates the actual value of the braking torque applied to the wheels 18a to 18d from the hydraulic braking system 20 and the braking torque request value T rb In this embodiment, the deviation of the braking torque requirement value T rb corresponds to the ideal value of the braking torque of the braking devices 16a to 16d. The cruise control ECU 50 corrects the output torque of the MGs 11a and 11b based on the deviation between these values, thereby preventing the braking torque actually applied to the wheels 18a to 18d from deviating from the basic braking torque. Furthermore, the cruise control ECU 50 sets upper and lower limit values ​​for the regenerative torque command values ​​of the MGs 11a and 11b, thereby preventing the absolute value of the output torque of the MGs 11a and 11b from becoming too large when the vehicle 10 stops. This enables the vehicle 10 to stop more smoothly.

[0038] Hereinafter, the control of the MGs 11a and 11b executed by the cruise control ECU 50 from when the vehicle 10 is decelerated until when the vehicle 10 is stopped will be described in detail. As shown in FIG. 3, the cruise control ECU 50 further includes, as functional elements realized by executing the program, a deceleration acquisition unit 60, a gradient disturbance acquisition unit 61, a deviation ratio calculation unit 62, a first deviation acquisition unit 63, and a second deviation acquisition unit 64.

[0039] The deceleration acquisition unit 60 acquires the actual value D of the deceleration of the vehicle 10 during deceleration of the vehicle 10. a and the ideal value D iDisturbance deceleration deviation Diff sum Calculate the following. Actual value D of the deceleration of the vehicle 10 a is the actual deceleration of the vehicle 10. The deceleration acquisition unit 60 acquires the vehicle speed V c By calculating the differential value of a Get.

[0040] The ideal deceleration value D of vehicle 10 i is the deceleration that should occur in the vehicle 10 based on the output torque of the MGs 11a and 11b, the rolling resistance of the road surface, etc. The deceleration acquisition unit 60 calculates the ideal value D of the deceleration of the vehicle 10 based on, for example, the following equation f1: i In the formula f1, "T" is the torque applied to the wheels 18a to 18d, "I" is the inertia of the body 17, and "R" is the radius of the tires of the wheels 18a to 18d.

[0041]

number

[0042]

number

[0043]

number

[0044] Inertia I in equation f2 fmg ,I rmg are also stored in advance in the ROM of the cruise control ECU 50. Furthermore, the information acquisition unit 51 calculates the road surface reaction torque T road is calculated based on the following formula f4. In formula f4, "α", "β", and "γ" are predetermined coefficients, and "V c " is the vehicle speed acquired by the information acquisition unit 51.

[0045]

number

[0046] Here, the vehicle 10 decelerates under the influence of not only the basic vehicle torque T but also other disturbance torques. The disturbance torques mainly include gradient disturbance torque acting on the vehicle 10 due to the influence of gravity when the vehicle 10 is positioned on a slope, and the deviation of the braking torque applied to the wheels 18a to 18d from the braking devices 16a to 16d. The deviation of the braking torque is the difference between the actual value of the braking torque applied to the wheels 18a to 18d by the hydraulic braking system 20 and the braking torque request value T rb The vehicle 10 actually decelerates under the influence of the basic vehicle torque T and the disturbance torque. c The actual value D of the deceleration of the vehicle 10 calculated from the differential value of a is the deceleration of the vehicle 10 that occurs based on the basic vehicle torque T and the disturbance torque.

[0047] The actual deceleration value D of the vehicle 10 as described above a and the ideal value D of the deceleration of the vehicle 10 i Based on the definitions of each, the deviation of the disturbance deceleration Diff sumis the disturbance deceleration of the vehicle 10 that occurs based on the deviation amount of the gradient disturbance torque and the braking torque. Specifically, the deceleration acquisition unit 60 acquires the actual value D a and the ideal value D of the deceleration of the vehicle 10 i Based on the following formula f5, the disturbance deceleration deviation Diff sum In equation f4, "LFP" represents the function of the low-pass filter, and "τ1" and "τ2" represent the time constants of the low-pass filter.

[0048]

number

[0049] Specifically, the acceleration A of the vehicle 10 detected by the acceleration sensor 35 sen contains not only the actual acceleration of the vehicle 10 but also the gravitational acceleration component of the vehicle 10. In response to this, the information acquisition unit 51 calculates the wheel speed ω wh (a)~ω wh (d) The acceleration A of vehicle 10 is calculated from wh is the actual acceleration of the vehicle 10. Using this, the gradient disturbance acquisition unit 61 calculates the acceleration A sen Acceleration A from wh By subtracting the gradient disturbance acceleration A slp Calculate the following.

[0050]

number

[0051]

number

[0052]

number

[0053] Therefore, the deviation ratio calculation unit 62 calculates the braking disturbance torque T brk,Dis calculated using the above formula f3. brk The deviation ratio is calculated by dividing by R pt In the formula f9, "Filter" represents a function based on a low-pass filter, for example.

[0054]

number

[0055]

number

[0056]

number

[0057] When the vehicle 10 comes to a stop on a slope and the braking torque of the braking devices 16a to 16d alone is not enough to keep the vehicle 10 stopped, the second deviation acquisition unit 64 calculates a correction value T slp In the following, the correction value T slp The gradient correction torque T slp In this embodiment, the gradient correction torque T slp corresponds to a second braking torque deviation, which is the deviation between the braking torque required to keep the vehicle 10 in a stopped state and the braking torque of the braking devices 16a to 16d when the vehicle 10 comes to a stop.

[0058] Specifically, the second deviation acquisition unit 64 calculates the gradient correction torque T slp In the formula f12, "K" is the feedback coefficient, and "ω mg " is the MG rotation speed acquired by the information acquisition unit 51, and "T0" is the initial value of the gradient correction torque.

[0059]

number

[0060]

number

[0061]

number

[0062] The MG control unit 53 outputs a torque command value T mg * The output torque of the MGs 11a and 11b is controlled based on the gradient correction torque T slpAs a result, when the braking torque of the braking devices 16a to 16d alone is not enough to keep the vehicle 10 stopped, torque equivalent to the shortage is output from the MGs 11a and 11b, making it possible to keep the vehicle 10 stopped.

[0063] Next, specific processing procedures executed by the elements of the cruise control ECU 50 as described above will be described with reference to FIGS. The cruise control ECU 50 repeatedly executes the process shown in Fig. 4 at a predetermined interval. As shown in Fig. 4, in the cruise control ECU 50, first, in step S10, the information acquisition unit 51 determines whether the Ready signal of the vehicle 10 is in an ON state. The vehicle 10 is provided with a Ready switch that is operated by the driver when starting the vehicle 10.

[0064] The Ready signal is an output signal of the Ready switch. When the driver turns on the Ready switch, the Ready signal is turned on. Therefore, the process of step S10 corresponds to a process of determining whether the vehicle 10 has started. If the determination in step S10 is affirmative, that is, if the Ready switch is in the on state, the information acquisition unit 51 performs the process in step S11 to obtain the hydraulic braking torque T brk is a predetermined torque threshold T th Specifically, the information acquisition unit 51 determines whether the wheel pressure P wc , and the hydraulic braking torque T is calculated based on the above equation f3 from the braking factor BEF pre-stored in the ROM. brk Calculate the torque threshold T th is determined in advance through experiments or the like so that it can be determined whether the brake pedal 21 is depressed or not, and is stored in the ROM of the cruise control ECU 50.

[0065] If the determination in step S11 is affirmative, that is, if the hydraulic braking torque T brk is a predetermined torque threshold Tth If the difference is equal to or greater than this, it is determined that the brake pedal 21 is being depressed. In this case, the cruise control ECU 50 calculates the deviation ratio R pt The specific procedure for this deviation ratio calculation process is as shown in FIG.

[0066] As shown in FIG. 5, in the deviation ratio calculation process, first, in step S20, the deceleration acquisition unit 60 calculates the disturbance deceleration deviation Diff sum Specifically, the deceleration acquisition unit 60 calculates the vehicle speed V c The actual value D of the deceleration of the vehicle 10 calculated from the differential value of a , and the ideal value D of the deceleration of the vehicle 10 calculated by the above equations f1 to f4. i Based on the above formula f5, the disturbance deceleration deviation Diff sum Calculate the following.

[0067] In step S21 following step S20, the gradient disturbance acquisition unit 61 acquires the acceleration A of the vehicle 10 detected by the acceleration sensor 35. sen and wheel speed ω wh (a)~ω wh (d) The acceleration A of vehicle 10 is calculated from wh Based on the above equation f6, the gradient disturbance acceleration A slp Calculate the following.

[0068] In step S22 following step S21, the deviation ratio calculation unit 62 calculates the disturbance deceleration deviation Diff sum and gradient disturbance acceleration A slp Based on the above formula f7, the braking disturbance deceleration Diff brk Calculate the following.

[0069] In step S23 following step S22, the deviation ratio calculation unit 62 calculates the deviation ratio R pt Specifically, the deviation ratio calculation unit 62 calculates the braking disturbance deceleration Diff brk Based on the above equation f8, the braking disturbance torque Tbrk,D The deviation ratio calculation unit 62 also calculates the hydraulic braking torque T brk Then, the deviation ratio calculation unit 62 calculates the braking disturbance torque T brk,D and hydraulic braking torque T brk Based on the above formula f9, the deviation ratio R pt Calculate the following.

[0070] The deviation ratio R obtained in this way pt By using the above formula f10, the correction torque T cor The travel control ECU 50 of this embodiment can calculate the correction torque T cor In order to improve the calculation accuracy of the deviation ratio R pt The average value of the deviation ratio R pt Corrected torque T based on the average value of cor Calculate the following.

[0071] Specifically, in step S24 following step S23, the deviation ratio calculation unit 62 calculates the deviation ratio integrated value Sum R,n and time integrated value Sum T,n The deviation ratio calculation unit 62 calculates the deviation ratio integrated value Sum based on the following formula f15: R,n In addition, in formula f15, "Sum R,n-1 " is the deviation ratio integrated value Sum R,n is the previous value of the time, and "ΔT" is a predetermined short time.

[0072]

number

[0073]

number

[0074] Thereafter, if a negative determination is made in the process of step S25, that is, if the brake pedal 21 is released, the deviation ratio calculation unit 62 calculates the average value Ave(R) of the deviation ratio based on the following equation f17 in the process of step S26: pt ) n Calculate the following.

[0075]

number

[0076] Therefore, the deviation ratio calculation unit 62 calculates the current average value Ave(R pt ) n and the previous average value Ave(R pt ) n-1 If the deviation from the predetermined value N is greater than or equal to the average deviation ratio Ave(R pt ) n The amount of fluctuation is limited to a predetermined value N.

[0077] Specifically, in step S27 following step S26, the deviation ratio calculation unit 62 calculates the average value Ave(R pt ) n the previous average value Ave(R pt ) n-1 Set to. In step S28 following step S27, the deviation ratio calculation unit 62 calculates the difference value Diff R Calculate the following.

[0078]

number

[0079]

number

[0080] On the other hand, if the determination in step S29 is negative, that is, the absolute value of the difference value |Diff R If | is less than the predetermined value N, the current average value Ave(R pt ) n is stored in the RAM as is, and then the processing shown in FIG. 5 is terminated.

[0081] 4 and 5, the average value Ave(R pt ) n is updated and the value is stored in RAM. During the execution of the switching control, the driving control ECU 50 calculates the average value Ave(R pt ) n Using the basic regenerative torque request value T rgr Next, the basic regenerative torque request value T rgr A specific procedure for this correction process will be described with reference to Fig. 6. The cruise control ECU 50 repeatedly executes the process shown in Fig. 6 at a predetermined calculation interval.

[0082] 6, in the cruise control ECU 50, first, in the process of step S40, the information acquisition unit 51 determines whether or not the Ready signal of the vehicle 10 is in an ON state. If the determination in the process of step S40 is affirmative, the information acquisition unit 51 also determines in the process of step S41 whether or not the hydraulic braking torque T brk is a predetermined torque threshold T th It is determined whether or not the above is the case. The processes of steps S40 and S41 are the same as the processes of steps S10 and S11 shown in Fig. 4, and therefore detailed description thereof will be omitted.

[0083] If the information acquisition unit 51 makes a positive determination in the processing of step S41, that is, if the brake pedal 21 is depressed, the information acquisition unit 51 determines whether the vehicle 10 is stopped or not in the processing of step S42. Specifically, in the process of step S42, the information acquisition unit 51 determines whether or not the following formula f20 is satisfied. ca ” is the wheel speed ω wh (a)~ω wh (d) is a vehicle speed that can be calculated using an arithmetic formula or the like from the average value of cb ” is the MG rotation speed ω fmg ,ω rmg The vehicle speed can be calculated using a formula etc. thb " is a threshold value that is set in advance so that it can be determined whether the vehicle is stopped or not, and is stored in the ROM of the cruise control ECU 50. "Max" is the vehicle speed V ca ,V cb The function that selects the larger of the speed threshold V thb is set to "0 [km / h]", for example.

[0084]

number

[0085] In step S46 following step S45, the switching control unit 55 calculates the torque command value T mg * Subsequently, in step S47, the MG control unit 53 sets the torque command value T mg * The output torque of the MGs 11a and 11b is controlled based on the basic regenerative torque request value T rgr Correction torque T cor is controlled to the value obtained by adding

[0086] Thereafter, when the vehicle 10 stops, the information acquisition unit 51 makes a positive determination in the process of step S42. In this case, in the process of step S43, the second deviation acquisition unit 64 calculates the gradient correction torque T slp In step S44 following step S43, the switching control unit 55 calculates the torque command value T mg * At this time, the switching control unit 55 sets the absolute value of the basic regenerative torque request value |T rgr | and absolute value of correction torque |T cor The larger of the two is the torque indication value T mg * The switching control unit 55 sets the upper limit value of "-|T rgr |" and "-|T corThe smaller of the two is the torque indication value T mg * Subsequently, in the process of step S47, the MG control unit 53 sets the torque command value T mg * As a result, the torque output from the MGs 11a and 11b is basically controlled based on the gradient correction torque T slp is controlled by.

[0087] Next, an example of the operation of the vehicle 10 of this embodiment will be described with reference to FIG. As shown in Fig. 7, if the brake pedal 21 is depressed at time t10, as shown in Fig. 7(A), the target torque setting unit 52 sets the basic braking torque to a value T10 corresponding to the depression amount Sb of the brake pedal 21. Also, as shown in Fig. 7(C), the target torque setting unit 52 sets the basic regenerative torque request value T rgr is set to a predetermined regenerative torque T20 corresponding to the basic braking torque T10, and this basic regenerative torque request value T rgr The torque indication value T mg * The predetermined regenerative torque T20 is a negative value. The MG control unit 53 transmits this torque command value T mg * As a result, as shown in FIG. 7(B), the sum of the output torques of the MGs 11a and 11b is controlled to a predetermined regenerative torque T20. c gradually decreases.

[0088] After that, at time t11, the vehicle speed V c is the switching speed V tha 7C, the switching control unit 55 starts the switching control. rgr | is gradually reduced from the predetermined absolute value of the regenerative torque |T20|, and the absolute value of the braking torque request value |T rbAs a result, the absolute value of the output torque of the MGs 11a and 11b gradually decreases from the predetermined absolute value of the regenerative torque |T20| as shown in Fig. 7(D), and the absolute value of the braking torque of the braking devices 16a to 16d gradually increases as shown in Fig. 7(F).

[0089] At this time, the torque command value T mg * Based on the above formula f11, the basic regenerative torque request value T rgr Correction torque T cor The correction torque T cor is set as shown by the two-dot chain line in FIG. 7C. As a result, the MGs 11a and 11b are driven in accordance with the regenerative torque request value T rgr In addition to the regenerative torque corresponding to the braking torque deviation of the braking devices 16a to 16d, a torque corresponding to the deviation of the braking torque of the braking devices 16a to 16d is output. This makes it difficult for the actual braking torque applied to the wheels 18a to 18d to deviate significantly from the basic braking torque T10. This makes it possible to stop the vehicle 10 more smoothly.

[0090] After that, as shown in FIG. 7(B), at time t12, the vehicle speed V c When the vehicle 10 is stopped, the basic regenerative torque request value T rgr is set to "0", while the braking torque request value T rb is the braking torque required when stopping, T stp Therefore, the braking torque T required for stopping is applied from the braking devices 16a to 16d to the wheels 18a to 18d. stp If the braking torque required for stopping output from the braking devices 16a to 16d is T stp If the vehicle 10 cannot be maintained in a stopped state by the above torque alone, the gradient correction torque T slp is output from MGs 11a and 11b. This gradient correction torque T slp This makes it possible to more reliably maintain the vehicle 10 in a stopped state.

[0091] According to the cruise control ECU 50 of the present embodiment described above, the following actions and effects (1) to (6) can be obtained. (1) After the switching control is started, the switching control unit 55 applies a correction torque T corresponding to the first braking torque deviation until the information acquisition unit 51 detects that the vehicle 10 is in a stopped state. cor After the information acquisition unit 51 detects that the vehicle 10 has come to a standstill, the switching control unit 55 corrects the output torque of the MGs 11a and 11b based on the gradient correction torque T slp The output torque of the MGs 11a and 11b is corrected based on the above. As a result, torque corresponding to the deviation in braking torque of the braking devices 16a to 16d is output from the MGs 11a and 11b, which makes it difficult for a situation to occur in which the braking force of the vehicle 10 is insufficient while suppressing a sudden change in the output torque of the MGs 11a and 11b. Therefore, it becomes possible to stop the vehicle 10 more smoothly.

[0092] (2) The information acquisition unit 51 receives the wheel pressure P wc The wheel pressure P wc Based on the above equation 3, the hydraulic braking torque T brk The first deviation acquisition unit 63 calculates the hydraulic braking torque T by using the above equations f9 and f10. brk From the above, the correction torque T corresponding to the first braking torque deviation is calculated. cor According to this configuration, it is possible to easily obtain the first braking torque deviation, which indicates the deviation between the actual value and the ideal value of the braking torque of the braking devices 16a to 16d.

[0093] (3) The deceleration acquisition unit 60 calculates the actual deceleration value D of the vehicle 10 based on the above formula f5. a and the ideal value D i Disturbance deceleration deviation Diff sum The gradient disturbance acquisition unit 61 acquires the gradient disturbance acceleration A that occurs in the vehicle 10 according to the gradient of the road surface on which the vehicle 10 is located, based on the above formula f6. slpThe deviation ratio calculation unit 62 calculates the disturbance deceleration deviation Diff as shown in the above formula f7. sum from the gradient disturbance acceleration A slp By subtracting the braking disturbance deceleration Diff brk and calculate the braking disturbance deceleration Diff based on the above formula f8. brk from braking disturbance torque T brk,D Furthermore, the deviation ratio calculation unit 62 calculates the braking disturbance torque T brk,D is calculated by the above formula f3, brk The deviation ratio R is calculated by dividing pt As shown in the above formula f3, the wheel pressure P wc The hydraulic braking torque T is calculated by multiplying this by the braking factor BEF. brk Based on the above, the first deviation acquisition unit 63 calculates the hydraulic braking torque T brk Deviation ratio R pt Correction torque T by multiplying cor According to this configuration, the correction torque T corresponding to the first braking torque deviation is calculated. cor can be easily calculated.

[0094] (4) The deviation ratio calculation unit 62 calculates the average value Ave(R pt ) n The first deviation acquisition unit 63 calculates the hydraulic braking torque T brk The average deviation ratio Ave(R pt ) n Correction torque T by multiplying cor According to this configuration, the correction torque T corresponding to the first braking torque deviation is calculated. cor can be calculated with higher precision.

[0095] (5) After the switching control is started, the switching control unit 55 continues to calculate the regenerative torque request value T rgrCorrection torque T cor The output torque of the MGs 11a, 11b is corrected by adding the above. With this configuration, torque corresponding to the deviation of the braking torque of the braking devices 16a to 16d is output from the MGs 11a, 11b, so that the actual braking torque applied to the wheels 18a to 18d is less likely to deviate significantly from the basic braking torque T10. This makes it possible to stop the vehicle 10 more smoothly.

[0096] (6) When correcting the output torques of the MGs 11a and 11b after detecting that the vehicle 10 has entered a stopped state, the switching control unit 55 sets the upper limit values ​​of the output torques to "Max(|T rgr |,|T cor |)" and set its lower limit to "Min(-|T rgr |,-|T cor With this configuration, it is possible to prevent the absolute value of the output torque of the MGs 11a and 11b from becoming too large after the motors are stopped.

[0097] The above embodiment can also be implemented in the following manner. The vehicle 10 is not limited to an electric vehicle, but may be a hybrid vehicle powered by both an engine and an MG. When the vehicle 10 is a hybrid vehicle, the torque command value T mg * may be the sum of the torque command value of the MG and the direct torque, which is the torque command value of the engine.

[0098] The configuration of the above embodiment is not limited to the vehicle 10 and can be applied to any moving body. The cruise control ECU 50 and control method thereof described in the present disclosure may be implemented by one or more special-purpose computers configured by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. The cruise control ECU 50 and control method thereof described in the present disclosure may be implemented by a special-purpose computer configured by configuring a processor including one or more dedicated hardware logic circuits. The cruise control ECU 50 and control method thereof described in the present disclosure may be implemented by one or more special-purpose computers configured by combining a processor and memory programmed to execute one or more functions with a processor including one or more hardware logic circuits. The computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium. The dedicated hardware logic circuit and the hardware logic circuit may be implemented by a digital circuit including multiple logic circuits or an analog circuit.

[0099] The present disclosure is not limited to the specific examples described above. Design modifications made by a person skilled in the art to the specific examples described above are also included within the scope of the present disclosure as long as they incorporate the features of the present disclosure. The elements of the specific examples described above, as well as their arrangement, conditions, shape, etc., are not limited to those exemplified and can be modified as appropriate. The elements of the specific examples described above can be combined in various ways as long as no technical contradictions arise. [Explanation of symbols]

[0100] 10: Vehicle (moving object) 11a, 11b: MG (rotating electric machine) 18a~18d: Wheel 16a~16d: Braking device 26a~26d: Wheel cylinder 50: Driving control ECU (control device) 51: Information acquisition department 55: Switching control unit 60:Deceleration acquisition part 61: Gradient disturbance acquisition unit 62: Deviation ratio calculation unit 63: First deviation acquisition unit 64: Second deviation acquisition unit

Claims

1. A control device (50) mounted on a moving body (10) having braking devices (16a to 16d) capable of applying braking torque to wheels (18a to 18d) and rotating electric machines (11a, 11b) capable of applying braking torque to the wheels by regenerative operation, a switching control unit (55) that executes switching control to reduce the braking torque of the rotating electric machine while increasing the braking torque of the braking device when decelerating the moving body; an information acquisition unit (51) that acquires information about the state of the moving body; a first deviation acquisition unit (63) that acquires a first braking torque deviation indicating a deviation between an actual value and an ideal value of the braking torque of the braking device during deceleration of the moving body; a second deviation acquisition unit (64) that acquires a second braking torque deviation indicating a deviation between a braking torque required to maintain the moving body in a stopped state and a braking torque of the braking device when the moving body comes to a stopped state, The switching control unit correcting the output torque of the rotary electric machine based on the first braking torque deviation during a period from when the switching control is started until when the information acquisition unit detects that the moving body is in a stopped state; After the information acquisition unit detects that the moving body has come to a stop, the output torque of the rotating electrical machine is corrected based on the second braking torque deviation. Control device for a moving object.

2. The moving body has wheel cylinders (26a to 26d) that apply hydraulic pressure to the braking device to drive the braking device, the information acquisition unit detects the pressure in the wheel cylinder, and calculates a predicted value of braking torque applied to the wheel from the braking device based on the detected pressure in the wheel cylinder; The first deviation acquisition unit calculates the first braking torque deviation based on the predicted value of the braking torque. The control device for a moving body according to claim 1 .

3. a deceleration acquisition unit (60) that acquires a deceleration deviation, which is a deviation between an actual value and an ideal value of the deceleration of the moving body; a gradient disturbance acquisition unit (61) that acquires gradient disturbance acceleration occurring in the moving body in accordance with the gradient of a road surface on which the moving body is located; a deviation ratio calculation unit (62) that calculates a deviation ratio by dividing a braking torque corresponding to a value obtained by subtracting the gradient disturbance acceleration from the deceleration deviation by a predicted value of the braking torque, The first deviation acquisition unit calculates the first braking torque deviation by multiplying the predicted value of the braking torque by the deviation ratio. The control device for a moving body according to claim 2.

4. the deviation ratio calculation unit calculates an average value of the deviation ratio during a period from when the information acquisition unit detects that the brake pedal of the moving body has been depressed until when the information acquisition unit detects that the brake pedal has been released; The first deviation acquisition unit calculates the first braking torque deviation by multiplying the predicted value of the braking torque by the average value of the deviation ratio. The control device for a moving body according to claim 3 .

5. The switching control unit corrects the output torque of the rotating electric machine by adding the first braking torque deviation to a torque request value requested of the rotating electric machine during a period from when the switching control is started until when the information acquisition unit detects that the moving body has come to a stop. The control device for a moving body according to any one of claims 1 to 3.

6. The switching control unit sets an upper limit value for the output torque of the rotating electric machine when correcting the output torque of the rotating electric machine after the information acquisition unit detects that the moving body has entered a stopped state. The control device for a moving body according to any one of claims 1 to 5.

7. The switching control unit sets at least one of the first braking torque deviation and a torque request value requested of the rotating electric machine as the upper limit value. The control device for a moving body according to claim 6.

8. The switching control unit sets a lower limit value for the output torque of the rotating electric machine when correcting the output torque of the rotating electric machine after the information acquisition unit detects that the moving body has come to a stop. The control device for a moving body according to any one of claims 1 to 7.

9. The switching control unit sets at least one of the first braking torque deviation and a torque request value requested of the rotating electric machine as the lower limit value. The control device for a moving body according to claim 8.

Images