Vehicle control device

Abstract

To prevent brake fade while reducing uncomfortable feeling of a driver.SOLUTION: In a vehicle control system, while a friction brake is not operated, driving force of a vehicle is restricted on the basis of a brake temperature that is a temperature of the friction brake. Thus compared to when traveling speed of the vehicle is restricted, uncomfortable feeling of a driver can be reduced. When the friction brake is operated next, an overheating state of the friction brake can be prevented so as to prevent generation of brake fade.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] In the vehicle control device described in Patent Document 1, when the brake temperature, which is the temperature of the friction brake, rises above a set temperature while the friction brake is in an inoperative state, the vehicle's traveling speed is limited, and the traveling speed is reduced the next time the friction brake is activated. This makes it difficult for the friction brake to overheat, and brake fade to occur. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Patent Application Publication No. 113320383 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0004] An object of the present invention is to make brake fade less likely to occur while reducing the sense of discomfort felt by the driver.

[0005] In the vehicle control system according to the present invention, when the friction brake is inactive, the vehicle's driving force is limited based on the brake temperature, which is the temperature of the friction brake. This reduces the driver's discomfort compared to when the vehicle's traveling speed is limited. Furthermore, the next time the friction brake is activated, the friction brake is less likely to overheat, making brake fade less likely to occur. [Brief explanation of the drawings]

[0006] [Figure 1] 1 is a diagram conceptually illustrating a vehicle control system according to an embodiment of the present invention. [Figure 2] 4 is a flowchart showing a driving force limiting program stored in a storage unit of the vehicle control system. [Figure 3] FIG. 4 is a diagram showing a mathematical formula used to acquire the brake temperature of the vehicle control system. [Figure 4] FIG. 2 is a conceptual diagram showing a friction brake from which the brake temperature is acquired. [Figure 5] 10 is a flowchart showing another driving force limiting program stored in a storage unit of the vehicle control system. [Figure 6] 10 is a flowchart showing yet another driving force limiting program stored in the storage unit. [Figure 7] FIG. 4 is a diagram illustrating an upper acceleration limit determination map stored in the storage unit. Embodiments of the invention

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A vehicle control system according to an embodiment of the present invention will now be described in detail with reference to the accompanying drawings. The vehicle control system controls a drive device of a vehicle. [Example]

[0008] The vehicle control system according to this embodiment includes a vehicle control ECU 20. The vehicle control ECU 20 is mainly a computer and includes a driving force limiting unit 22, a brake temperature acquiring unit 24, etc. The vehicle control ECU 20 controls the driving force applied to the vehicle by controlling a driving device 26. The vehicle control ECU 20 is connected to the driving device 26, a main switch 28, a running condition detecting device 30, an outside air temperature sensor 36, etc.

[0009] The drive unit 26 drives the vehicle. The drive unit 26 may or may not include an electric motor. The main switch 28 is a main switch that switches the entire vehicle on and off, and may be, for example, an ignition switch (IGSW) 28. The outside air temperature sensor 36 measures the outside air temperature, which is the temperature around the vehicle.

[0010] The running condition detection device 30 detects the running condition of the vehicle and includes a wheel speed sensor 32, an acceleration sensor 34, etc. The wheel speed sensors 32 are provided corresponding to each of the vehicle's multiple wheels and detect the rotational speed of each wheel. The running speed of the vehicle is obtained based on the rotational speeds of the multiple wheels. The acceleration sensor 34 detects the longitudinal acceleration (including deceleration) applied to the vehicle.

[0011] The brake temperature acquisition unit 24 estimates and acquires the brake temperature, which is the temperature of the friction brake 10. The friction brake 10 is provided on each wheel of a vehicle. As shown in FIG. 4, the friction brake 10 suppresses rotation of the wheel by frictionally engaging a pair of friction engagement members 14, 16 with a brake rotor 12 using an actuator 18. The brake rotor 12 is rotatable integrally with the wheel, and the friction engagement members 14, 16 are held by non-rotating bodies.

[0012] The brake temperature acquisition unit 24 may be, for example, a temperature estimation device described in Japanese Patent Application Laid-Open No. 2023-89822. The brake temperature acquisition unit 24 estimates and acquires the current brake temperature by adding the integrated value of the temperature change value ΔTb over time Δs to the initial value of the brake temperature. The brake temperature acquisition unit 24 constantly acquires the brake temperature while the IGSW 28 is ON.

[0013] The temperature change value ΔTb is acquired based on a value obtained by subtracting the amount of released energy, which is the amount of energy released from the brake rotor 12 during the time Δs, from the amount of supplied energy, which is the amount of energy supplied to the brake rotor 12 during the time Δs. The value obtained by subtracting the amount of released energy from the amount of supplied energy can be considered to be the amount of absorbed energy, which is the amount of energy absorbed in the brake rotor 12 during the time Δs.

[0014] When the friction brake 10 is in operation and the amount of supplied energy is greater than the amount of released energy, the temperature change value ΔTb is often a positive value. On the other hand, when the friction brake 10 is in an inoperative state, the amount of supplied energy is 0, so the temperature change value ΔTb is obtained based on the amount of released energy. The temperature change value ΔTb is often a negative value.

[0015] As shown in equation (1) in FIG. 3, when the friction brake 10 is in operation, the amount of absorbed energy Qin absorbed during time Δs in the brake rotor 12 of the friction brake 10 of one wheel can be obtained by subtracting the amount of released energy Qout released from the amount of supplied energy Qst. The amount of supplied energy Qst is the amount of energy supplied to the brake rotor 12 of one friction brake 10 due to the operation of the friction brake 10 of one wheel during time Δs. The amount of supplied energy can be obtained as the amount of energy Qst lost by the vehicle due to the operation of one friction brake 10 for time Δs. The amount of released energy Qout is the amount of energy released from one brake rotor 12 during time Δs.

[0016] As shown in equation (2), the amount of energy Qst lost by the vehicle due to the operation of one friction brake 10 for time Δs can be expressed as the amount of kinetic energy Qst1 lost by the vehicle for one wheel during time Δs and the amount of potential energy Qst2 lost by the vehicle per wheel during time Δs. The vehicle decelerates when the friction brake 10 is operated, but when traveling uphill, the vehicle also decelerates due to the uphill gradient. Therefore, when obtaining the amount of energy Qst lost by the vehicle due to the operation of one friction brake 10 for time Δs, the amount of kinetic energy lost by the vehicle during time Δs and the amount of potential energy Qst2 lost by the vehicle during time Δs are taken into consideration. In this embodiment, the amount of potential energy ΔU lost by the vehicle while traveling on an uphill road is taken as a negative value, and the amount of potential energy ΔU lost by the vehicle while traveling on a downhill road is taken as a positive value.

[0017] The amount of kinetic energy Qst1 lost by a vehicle for one wheel over time Δs can be expressed using ΔK, β, C1, C2, etc., as shown in equation (3). ΔK is the amount of kinetic energy lost by the entire vehicle. β is the front / rear braking force distribution ratio. C1 is the running resistance loss coefficient. C2 is a coefficient that represents energy loss caused by resistance due to friction between the wheel and the road surface, etc. 1 / 2 is used to calculate the amount of kinetic energy per wheel. Since there are two wheels on each of the front and rear wheels, it is multiplied by 1 / 2. The amount of kinetic energy ΔK lost by the entire vehicle can be expressed using M, Vbe, and V, as shown in equation (4). M is the vehicle mass. Vbe is the running speed from time Δs ago. V is the current running speed.

[0018] The amount of potential energy Qst2 lost per wheel by the vehicle during time Δs can be expressed using ΔU, β, C1, C2, etc., as shown in equation (5). ΔU is the amount of potential energy lost in the entire vehicle. ΔU can be expressed using M, Vs, g, θ, and Δs, as shown in equation (6). Vs is the average speed during time Δs. For simplicity, the average speed Vs can be the current speed V or the speed Vbe from time Δs ago. g is the acceleration due to gravity, and θ is the road gradient. In equation (6), "Vs*Δs*sinθ" represents the difference in elevation between the vehicle's positions. Note that * represents multiplication.

[0019] The road gradient θ can be obtained based on the detection value of the acceleration sensor 34. The detection value of the acceleration sensor 34 includes the acceleration caused by changes in the wheel speed detected by the wheel speed sensor 32 and the acceleration caused by the road gradient θ. Therefore, the acceleration caused by the road gradient can be obtained by subtracting the acceleration caused by changes in the traveling speed from the detection value of the acceleration sensor 34.

[0020] Furthermore, when obtaining the amount of energy Qst lost by the vehicle due to the operation of one friction brake 10 for the time Δs, the amount of energy Qst3 lost due to regenerative braking may also be taken into consideration.

[0021] On the other hand, the amount of energy Qout released by the brake rotor 12 for a time Δs for one wheel can be expressed using h, A, Tbe, Tatm, and Δs, as shown in equation (7). h is the thermal conductivity of the brake rotor 12. A is the area of ​​the sliding portion between the brake rotor 12 and the friction engagement members 14, 16. Tbe is the brake temperature before time Δs. Tatm is the outside air temperature. The outside air temperature Tatm can be obtained as a detection value of the outside air temperature sensor 36.

[0022] The amount of absorbed energy Qin changes the temperature of the brake rotor 12. Therefore, as shown in equation (8), the temperature change value ΔTb of the brake rotor 12 during the time Δs can be expressed using Qin, wb, and C, where wb is the mass of the brake rotor 12 and C is the specific heat of the brake rotor 12.

[0023] The initial value Tro of the brake temperature, which is the temperature of the brake rotor 12 when the IGSW 28 is switched from OFF to ON this time, can be expressed as shown in equation (9). If a sufficiently long set time has elapsed since the previous time when the IGSW 28 was switched from ON to OFF until the current time when the IGSW 28 is switched from OFF to ON, the initial value Tro is set to the outside air temperature Tatm.

[0024] On the other hand, if the time elapsed since the IGSW 28 was last switched from ON to OFF is shorter than the set time, the initial value Tro can be expressed using Tro_IGOFF, hstop, and sIGOFF. Tro_IGOFF is the temperature of the brake rotor 12 when the IGSW 28 is switched from ON to OFF. hstop is the thermal conductivity when the vehicle is stopped. sIGOFF is the elapsed time while the IGSW 28 is OFF.

[0025] As shown in equation (10), the current brake temperature Tb is obtained by adding the integrated value of the temperature change value ΔTb over the time Δs to the initial brake temperature value Tro obtained in equation (9). In other words, the brake temperature (current value) Tb(n) is obtained by adding the temperature change value ΔTb over the time Δs to the previously obtained brake temperature Tb(n-1).

[0026] When the brake temperature Tb exceeds a predetermined threshold Tsth while the friction brake 10 is in an inoperative state, the driving force is limited so that the acceleration does not exceed the upper limit αsth. Limiting the driving force suppresses an increase in the vehicle's traveling speed, making it difficult for the traveling speed to exceed a set speed. This makes it difficult for the friction brake 10 to be activated next time when the traveling speed is faster than the set speed. This is because if the friction brake 10 is activated when the traveling speed is faster than the set speed, a high load is applied to the friction brake 10, causing the brake temperature to rise and making brake fade more likely to occur. Limiting the driving force also lengthens the time it takes for the vehicle's traveling speed to exceed the set speed, thereby lengthening the cooling time of the friction brake 10. This allows the friction brake 10 to be adequately cooled before the next friction brake 10 is activated. These factors make it difficult for brake fade to occur.

[0027] In this embodiment, for example, the start threshold value Tsth and the upper limit value αsth of acceleration can be set in advance based on changes in brake temperature and the like when the vehicle is assumed to have traveled in a predetermined set pattern. For example, when the vehicle is assumed to have traveled in a predetermined set pattern, if the drive force is restricted so that the acceleration does not exceed the upper limit value αsth from the point when the brake temperature Tb reaches the start threshold value Tsth, the start threshold value Tsth and the upper limit value αsth can be acquired and set based on the cooling effect and the like until the next time the friction brake 10 is activated.

[0028] The set pattern can be, for example, "(i) accelerate to a set speed vp1, (ii) activate the friction brake 10 and decelerate at a deceleration rate Gp1 until the traveling speed reaches the set speed vp2, (c) travel at the set speed vp2 for a set time, repeated a set number of times np." In the set pattern, the set speed vp1 can be, for example, a speed at which the friction brake 10 is considered to be in a high-load state, i.e., a state in which a high load is applied to the friction brake 10 when the friction brake 10 is activated. When the vehicle travels according to the set pattern, the friction brake 10 enters a high-load state each time the friction brake 10 is activated, and the brake temperature increases. After the friction brake 10 has been activated the set number of times np, the friction brake 10 is considered to be in an overheated state, and brake fade is likely to occur.

[0029] From the above, in this embodiment, the start threshold value Tsth can be set to a temperature lower than the temperature at which the friction brake 10 is considered to be in an overheated state. The limiting of the driving force starts when the brake temperature Tb reaches the start threshold value Tsth, and this temperature can effectively prevent the friction brake 10 from becoming overheated.

[0030] The start threshold Tsth and upper limit αsth of acceleration are determined by vehicle specifications such as vehicle weight, cooling performance, brake size, and front / rear braking force distribution ratio.

[0031] For example, for a heavy vehicle, the start threshold and upper acceleration limit are set to smaller values ​​than for a lighter vehicle. This is because a heavy vehicle is more likely to be subjected to a high load on the friction brake 10. Also, for a friction brake 10 with excellent cooling performance, the start threshold and upper acceleration limit are set to larger values ​​than for a friction brake with poor cooling performance. This is because there is less need to limit the driving force. For example, if the brake rotor 12 has a ventilated structure, it is considered that the cooling performance is excellent. For a friction brake 10 with a large brake size, the start threshold and upper acceleration limit are set to larger values ​​than for a smaller friction brake. This is because a brake rotor 12 with a large brake size dissipates heat more easily. Based on the front / rear braking force distribution ratio, the start threshold and upper acceleration limit are often set to smaller values ​​for the friction brakes on the front wheels than for the friction brakes on the rear wheels. Also, when the braking force distribution ratio is large, the start threshold and upper acceleration limit for the front friction brakes 10 are set to smaller values ​​than when it is small. This is because, in the case of the front wheels, when the braking force distribution ratio is large, the pressing force that presses the friction engagement members 14, 16 against the brake rotor is increased, and the friction force is often increased.

[0032] In the vehicle control system configured as described above, the driving force limiting program shown in the flowchart of Fig. 2 is executed at predetermined intervals. The driving force limiting program is executed in the driving force limiting unit 22 while the friction brake 10 is in a non-operating state. In step 1 (hereinafter abbreviated as S1, the same applies to the other steps), it is determined whether or not the driving force is being limited. If the determination is NO, in S2, the brake temperature Tb acquired by the brake temperature acquisition unit 24 is read, and in S3, it is determined whether or not the brake temperature Tb is higher than the start threshold value Tsth. If the determination is NO, S4 and subsequent steps are not executed.

[0033] If the determination in S3 is YES, in S4, the upper limit value αsth of the acceleration is obtained, and in S5, the driving force is limited by controlling the driving device 26 so that the acceleration α detected by the acceleration sensor 34 does not become greater than the upper limit value αsth.

[0034] While the driving force is being limited, the determination in S1 is YES, and in S6 it is determined whether the brake temperature Tb has become lower than the end threshold Teth, which is a value smaller than the start threshold Tsth. If the determination is NO, the driving force continues to be limited, and if the determination is YES, the driving force limit control is ended in S7.

[0035] As described above, in this embodiment, the driving force is limited when the brake temperature Tb becomes higher than the start threshold Tsth. As a result, brake fade is less likely to occur the next time the friction brake 10 is activated. Furthermore, compared to when the traveling speed is limited, the flow of vehicles is less likely to be disrupted, reducing the sense of discomfort felt by the driver. Furthermore, by setting the end threshold Teth to a value smaller than the start threshold Tsth, the number of times the driving force limit control is executed can be reduced. Furthermore, by setting the start threshold Tsth and the end threshold Teth to different values, hunting can be suppressed. As a result, the commercial value can be increased.

[0036] It is possible to provide a plurality of threshold values ​​Tsth for starting the drive force limit control so that the upper limit value αsth of the acceleration can be reduced in stages, as shown in FIG.

[0037] In this embodiment, a first start threshold Tsth1, a second start threshold Tsth2, a third start threshold Tsth3, and an end threshold Teth are set, with the first start threshold Tsth1, the second start threshold Tsth2, the third start threshold Tsth3, and the end threshold Teth being values ​​that decrease in this order. Tsth1>Tsth2>Tsth3>Teth

[0038] In addition, for the upper limit value αsth of acceleration, a first upper limit value αsth1, a second upper limit value αsth2, and a third upper limit value αsth3 are set, and these first upper limit value αsth1, second upper limit value αsth2, and third upper limit value αsth3 are values ​​that increase in this order. αsth1<αsth2<αsth3

[0039] The driving force limiting program shown in the flowchart of FIG. 5 is executed at predetermined intervals while the friction brake 10 is in a non-operating state. In S1, it is determined whether the driving force is being limited. If the determination is NO, then in S2, brake temperature Tb is acquired. Then, in S13-15, it is determined whether brake temperature Tb is higher than a first start threshold Tsth1, a second start threshold Tsth2, or a third start threshold Tsth3. If the determination is YES in S15, then in S16, the upper limit of acceleration is set to a third upper limit αsth3, and driving force limit control is initiated in S17. If the determination is YES in S14, then in S18, the upper limit αsth2 is set to a second upper limit αsth2, and if the determination is YES in S13, then the upper limit αsth1 is set to a first upper limit αsth1.

[0040] In this way, the upper limit of acceleration is gradually reduced as the brake temperature Tb increases, which further reduces the driver's discomfort and makes it difficult for traffic to be disrupted, thereby increasing the product value.

[0041] Furthermore, the upper limit value αsth of acceleration can be continuously reduced as the brake temperature Tb increases. An example of this is shown in Figures 6 and 7. Figure 7 shows an example of the relationship between the upper limit value αsth of acceleration and the brake temperature Tb. As shown in Figure 7, the upper limit value αsth of acceleration decreases as the brake temperature Tb increases, but when the brake temperature Tb is lower than the set temperature Tbx, the upper limit value of acceleration is set to the set value αmax. In this case, it is considered that the driving force is not actually limited so that the acceleration does not exceed the set value αmax.

[0042] The map in Fig. 7 is created and stored in advance, and it is desirable that the map in Fig. 7 be created for each vehicle based on the vehicle specifications.

[0043] Furthermore, in this embodiment, the number of times N the friction brake 10 is activated under high load conditions is counted, and when the number of times N exceeds a limit start number Nsth, which is a number that is smaller than the set number of times np, drive force limit control is initiated. This is because it is known that when the number of times the friction brake 10 is activated under high load conditions exceeds the set number of times np, the friction brake 10 will overheat, making brake fade more likely to occur. If the friction brake 10 is activated under conditions where the vehicle speed is faster than the set speed vp1, it can be assumed that the vehicle is under high load. Therefore, in this embodiment, the number of times N the friction brake 10 is activated under conditions where the speed is faster than the set speed vp1 is counted.

[0044] In the flowchart of Fig. 6, brake temperature Tb is acquired in S31, the number of times N that friction brake 10 has operated under high load is acquired in S32, and it is determined in S33 whether the number of times N is greater than the limit start number Nsth. If the determination is YES, upper limit value αsth is acquired based on brake temperature Tb in S34 and on the map shown in Fig. 7, and drive force limit control is performed in S35.

[0045] In this way, the upper limit value αsth of the acceleration is set to a value that continuously decreases as the brake temperature Tb increases, so that the sense of discomfort felt by the driver can be further alleviated.

[0046] As described above, in the above embodiment, the vehicle control ECU 20 can be considered to correspond to the vehicle control unit, and the driving force limiting unit 22 can also be considered to correspond to the vehicle control unit.

[0047] It should be noted that steps S32 and S33 are not essential in the flowchart of Fig. 6. When the friction brake 10 is in a non-operating state, the upper limit value αsth of the acceleration may be set constantly based on the brake temperature Tb.

[0048] The brake temperature may be acquired by the vehicle control ECU 20 or an external computer. In other words, the brake temperature acquisition unit 24 and the driving force limiting unit 22 are based on a common computer, but they may be based on separate computers. Furthermore, the brake temperature acquisition unit 24 may be located outside the vehicle. The method of acquiring the brake temperature is not limited to that of this embodiment.

[0049] Furthermore, the present vehicle control system can be installed in hybrid vehicles, electric vehicles, engine-driven vehicles, etc., and the present invention can be implemented in various forms, including those described above, with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0050] 10: Friction brake 12: Brake rotor 20: Vehicle control ECU 22: Driving force limiting unit 24: Brake temperature acquisition unit 26: Drive unit 28: IGSW 30: Driving state detection device 36: Outside air temperature sensor Patentable invention

[0051] (1) A vehicle control system for controlling a vehicle, A vehicle control system including a vehicle control unit that limits a driving force applied to the vehicle based on a brake temperature, which is the temperature of a friction brake provided on a wheel of the vehicle.

[0052] (2) The vehicle control system described in (1), wherein the vehicle control unit starts limiting the driving force when the brake temperature becomes higher than a threshold value, which is a start threshold value, while the friction brake is in a non-operating state.

[0053] (3) A vehicle control system as described in paragraph (2), wherein the vehicle control unit starts limiting control of the driving force when the brake temperature becomes higher than the start threshold value, and ends limiting the driving force when the brake temperature becomes lower than an end threshold value that is a value smaller than the start threshold value.

[0054] (4) A vehicle control system described in any one of (1) to (3), wherein the vehicle control unit limits the driving force so that the acceleration of the vehicle does not exceed a first upper limit value when the brake temperature is higher than a first start threshold, and limits the driving force so that the acceleration does not exceed a second upper limit value that is higher than the first upper limit value when the brake temperature is equal to or lower than the first start threshold value and higher than a second start threshold value.

[0055] At least one of the upper limit of acceleration and the brake temperature start threshold can be set based on vehicle specifications. For example, for vehicles with excellent cooling and heat dissipation capabilities of friction brakes, there is little need to limit the driving force. Therefore, for vehicles with excellent cooling and heat dissipation capabilities, the upper limit of acceleration and the start threshold can be set to a higher value than for vehicles with poor cooling and heat dissipation capabilities. Furthermore, for vehicles in which a large pressing force is applied by the friction brakes, there is a high need to limit the driving force. Therefore, for vehicles with friction brakes that apply a large pressing force, it is desirable to set the start threshold and the upper limit of acceleration to a lower value than for vehicles with friction brakes that apply a small pressing force.

[0056] (5) A vehicle control system described in any one of (1) to (4), wherein the vehicle control unit sets an upper limit value of acceleration as a limit value of the driving force based on the brake temperature, and limits the driving force so that the acceleration does not exceed the upper limit value.

[0057] (6) A vehicle control system according to any one of (1) to (5), wherein the vehicle control unit sets an upper limit value of acceleration as a limit value of the driving force to a smaller value as the brake temperature increases, and limits the driving force so that the acceleration does not exceed the upper limit value.

[0058] It is desirable that the relationship between the brake temperature and the upper limit of acceleration be mapped and stored in advance in a storage unit.

[0059] (7) The vehicle control system includes a brake temperature acquisition unit that acquires the brake temperature, The vehicle control system according to any one of (1) to (6), wherein the brake temperature acquisition unit acquires the brake temperature based on an energy balance in the friction brake.

[0060] The energy balance in the friction brake can be obtained based on the vehicle specifications, driving conditions, outside air temperature, and the like.

Claims

1. A vehicle control system for controlling a vehicle, A vehicle control system including a vehicle control unit that limits a driving force applied to the vehicle based on a brake temperature, which is the temperature of a friction brake provided on a wheel of the vehicle.

2. 2. The vehicle control system according to claim 1, wherein the vehicle control unit starts limiting the driving force when the brake temperature becomes higher than a threshold value, which is a start threshold, while the friction brake is in an inoperative state, and ends limiting the driving force when the brake temperature becomes lower than a threshold value, which is lower than the start threshold.

3. 3. The vehicle control system of claim 1, wherein the vehicle control unit limits the driving force so that the acceleration of the vehicle does not exceed a first upper limit value when the brake temperature is higher than a first start threshold, and limits the driving force so that the acceleration does not exceed a second upper limit value that is greater than the first upper limit value when the brake temperature is lower than the first start threshold and higher than a second start threshold.

4. 3. The vehicle control system according to claim 1, wherein the vehicle control unit sets an upper limit value of acceleration as a limit value of the driving force based on the brake temperature, and limits the driving force so that the acceleration does not exceed the upper limit value.

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