Vehicle battery protection device

Abstract

To protect the battery, we will limit the increase in the number of vehicle parts. [Solution] The battery protection device 20 includes a lidar 22 or camera 24 that detects obstacles in the direction of travel of a vehicle equipped with an air suspension system 50 that allows for vehicle height adjustment and has a battery located below the floor of the vehicle body. When the control unit 44 determines that an obstacle detected by the lidar 22 or camera 24 may come into contact with the battery, it controls the air suspension system 50 and the MG62 or brake system 66 to adjust the minimum ground clearance and attitude of the vehicle body.

Description

Technical Field

[0001] This disclosure relates to a battery protection device for a vehicle.

Background Art

[0002] Patent Document 1 describes a battery protection member in which an inclined surface and a buffer chamber are formed. When the battery protection member receives a collision of an obstacle on the inclined surface, it deflects and deform rearward, and at the same time, the buffer chamber also absorbs the collision to doubly absorb the energy generated by the collision with the obstacle.

Prior Art Documents

Patent Documents

[0003] [[ID=2's2]]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technique described in Patent Document 1 is configured to protect the battery from obstacles by providing a protection member around the battery. However, there is a problem that an increase in the number of vehicle parts leads to an increase in vehicle weight and cost.

[0005] This disclosure is made in consideration of the above facts, and an object thereof is to obtain a vehicle battery protection device that can suppress an increase in the number of vehicle parts when protecting the battery.

Means for Solving the Problems

[0006] A battery protection device for a vehicle according to the first embodiment includes a detection unit that detects obstacles in the direction of travel of a vehicle in which a battery is located below the floor of the vehicle body and an active suspension system capable of adjusting the vehicle height is provided, and a control unit that, when it is determined by the detection unit that the obstacle detected may come into contact with the battery, controls the active suspension system and the drive system or braking system of the vehicle to adjust the minimum ground clearance and attitude of the vehicle body.

[0007] In the first embodiment, when it is determined that an obstacle in the direction of travel of the vehicle may come into contact with the battery located below the floor of the vehicle, the active suspension system provided on the vehicle is controlled, and the vehicle's drive system or braking system is controlled to adjust the minimum ground clearance and attitude of the vehicle. In this way, in the first embodiment, by adjusting the minimum ground clearance and attitude of the vehicle, it is possible to suppress obstacles from coming into contact with the battery, thus eliminating the need to provide protective members around the battery to protect it, and thus suppressing an increase in the number of parts of the vehicle.

[0008] In the second embodiment, in the first embodiment, the detection unit detects the height of an obstacle in the direction of travel of the vehicle, and the control unit determines that there is a possibility that the obstacle may come into contact with the battery if the height of the obstacle detected by the detection unit is equal to or greater than the current minimum ground clearance of the vehicle body.

[0009] In the second embodiment, the height of the obstacle is detected, and if the height of the obstacle is greater than or equal to the vehicle's current minimum ground clearance, it is determined that the obstacle may come into contact with the battery. This allows for an accurate determination of whether or not an obstacle may come into contact with the battery.

[0010] In a third embodiment, in the second embodiment, the control unit controls the active suspension device so as to increase the minimum ground clearance on the front and rear wheel sides of the vehicle when the height of the obstacle detected by the detection unit is less than a predetermined value, and also increases the driving torque applied by the drive unit to the rear wheel of the vehicle.

[0011] In the third embodiment, the active suspension system is controlled to increase the minimum ground clearance on both the front and rear wheel sides of the vehicle, and the drive torque applied by the drive system to the rear wheels of the vehicle is increased. As a result, the vehicle body assumes a rearward tilt posture where the side in the direction of travel is higher than the opposite side, and obstacles below a predetermined height can pass through the space below the vehicle body without coming into contact with the battery.

[0012] A fourth aspect is that, in the second aspect, the control unit controls the active suspension device such that the minimum ground clearance on the front wheel side of the vehicle decreases and the minimum ground clearance on the rear wheel side of the vehicle increases when the height of the obstacle detected by the detection unit is greater than or equal to a predetermined value, and also increases the braking torque applied by the braking device to the front wheels of the vehicle.

[0013] In the fourth embodiment, the active suspension system is controlled so that the minimum ground clearance on the front wheels of the vehicle decreases and the minimum ground clearance on the rear wheels of the vehicle increases, and the braking torque applied by the braking system to the front wheels of the vehicle is increased. As a result, the vehicle body assumes a forward-leaning posture where the side in the direction of travel is lower than the opposite side, and when an obstacle of a height greater than a predetermined value collides with a component located at the front end of the vehicle in the direction of travel (e.g., a bumper), the obstacle can be prevented from entering the space below the vehicle body and coming into contact with the battery. [Effects of the Invention]

[0014] This disclosure has the effect of preventing an increase in the number of vehicle parts when protecting the battery. [Brief explanation of the drawing]

[0015] [Figure 1] This is a block diagram showing a schematic configuration of a battery protection device according to an embodiment. [Figure 2] This is an illustrative diagram showing an example of a vehicle and an obstacle. [Figure 3] This flowchart shows the posture and vehicle height control process. [Figure 4] (A) is an illustrative diagram showing the steady state, and (B) is an illustrative diagram showing the state with the vehicle body tilted backward. [Figure 5] (A) is an illustrative diagram showing the steady state, and (B) is an illustrative diagram showing the state with the vehicle body tilted forward. [Modes for carrying out the invention]

[0016] Hereinafter, an example of an embodiment of the present disclosure will be described in detail with reference to the drawings. Figure 1 shows a battery protection device 20 according to this embodiment. As shown in Figure 2, in a vehicle 10 equipped with the battery protection device 20, the battery 12, which serves as the drive source for the MG (motor generator) 62, is located below the floor of the vehicle body. The vehicle 10 may be a PHEV (Plug-in Hybrid Electric Vehicle), a BEV (Battery Electric Vehicle), or a HEV (Hybrid Electric Vehicle).

[0017] The battery protection device 20 is a device for preventing the battery 12 from coming into contact with an obstacle 14, and includes a LiDAR (Light Detection and Ranging) 22 and a camera 24. The LiDAR 22 is installed at the front end of the vehicle 10 and emits laser light in front of the vehicle 10, detecting the distance and height H (see Figure 2) to the obstacle 14 in front of the vehicle 10 based on the information from the reflected light.

[0018] The camera 24 is composed of a stereo camera and is provided inside the vehicle compartment of the vehicle 10, etc. The camera 24 photographs the front of the vehicle 10 and detects the distance and height H to the obstacle 14 existing in front of the vehicle 10 based on the parallax on the left and right images obtained by the photographing. The lidar 22 and the camera 24 are connected to the advanced safety integrated ECU (Electronic Control Unit) 30 and output the detection results of the obstacle 14 to the advanced safety integrated ECU 30. The lidar 22 and the camera 24 are an example of the detection unit in the present disclosure.

[0019] In addition, the vehicle 10 is provided with an air suspension device 50 capable of independently adjusting the vehicle height of the four wheels, and the air suspension device 50 is connected to the advanced safety integrated ECU 30. The air suspension device 50 includes a compressor 52, an electromagnetic valve 54, an airbag 56, and a control ECU 58. The compressor 52 is connected to a pressure-resistant tank, and the compressed air generated by the compressor 52 is stored in the pressure-resistant tank. Also, the airbag 56 is provided on each of the four wheels of the vehicle 12 in place of the metal spring in a normal suspension. Each individual airbag 56 is connected to the pressure-resistant tank via an air supply electromagnetic valve 54 and is also connected to the exhaust electromagnetic valve 54.

[0020] When the control ECU 58 raises the vehicle height (the lowest ground clearance) of the vehicle 10, it opens the air supply electromagnetic valve 54 connected to the airbag 56. As a result, the compressed air stored in the pressure-resistant tank flows into the airbag 56, and the overall length of the airbag 56 extends, thereby raising the vehicle height of the vehicle 10 and increasing the lowest ground clearance. Also, when the control ECU 58 lowers the vehicle height (the lowest ground clearance) of the vehicle 10, it opens the exhaust electromagnetic valve 54 connected to the airbag 56. As a result, the air is exhausted from the airbag 56, and the overall length of the airbag 56 shrinks, thereby lowering the vehicle height of the vehicle 10 and decreasing the lowest ground clearance. The air suspension device 50 is an example of the active suspension device in the present disclosure.

[0021] Further, the advanced safety integrated ECU 30 is connected to an MG (motor generator) 62 via a drive control ECU 60, and is connected to a brake device 66 via a brake control ECU 64. The MG 62 is provided on each wheel of the vehicle 10, and the drive control ECU 60 is capable of controlling the drive of the MG 62 for each wheel of the vehicle 10. The drive control ECU 60 and the MG 62 are an example of a drive device in the present disclosure. Also, the brake control ECU 64 is capable of separately controlling the braking torque generated by the brake device 66 for the front wheels and the rear wheels of the vehicle 10. The brake control ECU 64 and the brake device 66 are an example of a braking device in the present disclosure.

[0022] The advanced safety integrated ECU 30 incorporates a CPU (Central Processing Unit) 32, a memory 34 such as a ROM (Read Only Memory) and a RAM (Random Access Memory), a storage 36 such as a HDD (Hard Disk Drive) and a SSD (Solid State Drive), an input / output I / F (InterFace) 38, and a communication I / F 40.

[0023] An attitude and vehicle height control program 42 is stored in the storage 36. The advanced safety integrated ECU 30 functions as a control unit 44 when the attitude and vehicle height control program 42 is read from the storage 36 and expanded in the memory 34, and the attitude and vehicle height control program 42 expanded in the memory 34 is executed by the CPU 32. When the control unit 44 determines that there is a possibility that the obstacle 14 detected by the lidar 22 or the camera 24 may come into contact with the battery 12, the control unit 44 controls the air suspension device 50 and controls the drive control ECU 60 or the brake control ECU 64 to adjust the minimum ground clearance and attitude of the vehicle body of the vehicle 10.

[0024] Next, as the operation of the present embodiment, the attitude and vehicle height control process executed by the advanced safety integrated ECU 30 (control unit 44) while the ignition switch of the vehicle 10 is on will be described with reference to FIG. 3.

[0025] In step 70 of the attitude and vehicle height control process, the control unit 44 causes the lidar 22 or camera 24 to search for obstacles 14 in front of the vehicle 10. In step 72, the control unit 44 determines whether or not obstacles 14 in front of the vehicle 10 have been detected by the lidar 22 or camera 24. If there are no obstacles 14 in front of the vehicle 10, the determination in step 72 is negated and the process returns to step 70.

[0026] Furthermore, if an obstacle 14 is present in front of the vehicle 10, the determination in step 72 is affirmed and the process proceeds to step 74. In step 74, the control unit 44 obtains the height H of the obstacle 14 present in front of the vehicle 10 from the lidar 22 or camera 24 and determines the relationship between the height H of the obstacle 14 and the current minimum ground clearance of the vehicle 10. If the height H of the obstacle 14 is lower than the current minimum ground clearance of the vehicle 10, it can be determined that the obstacle 14 is unlikely to come into contact with the battery 12. Therefore, if the height H of the obstacle 14 is lower than the current minimum ground clearance of the vehicle 10, the process returns from step 74 to step 70.

[0027] Furthermore, if the height H of the obstacle 14 is greater than or equal to the current minimum ground clearance of the vehicle 10, it can be determined that the obstacle 14 may come into contact with the battery 12. For this reason, if the height H of the obstacle 14 is greater than or equal to the current minimum ground clearance of the vehicle 10, the system proceeds from step 74 to step 76. In step 76, the control unit 44 activates the brake device 66 via the brake control ECU 64 to decelerate the vehicle 10. This improves the likelihood of avoiding a collision with the obstacle 14, as the vehicle 10 can be stopped before the obstacle 14 by the activation of the brakes, especially if the original vehicle speed is low.

[0028] In the next step 78, the control unit 44 determines whether a collision with the obstacle 14 can be avoided by the operation of the brakes. If the determination in step 78 is affirmative, the process returns to step 70. If the determination in step 78 is negative, the process proceeds to step 80, in which the control unit 44 compares the height H of the obstacle 14 with the maximum value Hmax of the minimum ground clearance achievable by the air suspension device 50, and branches according to the comparison result. The maximum value Hmax of the minimum ground clearance achievable by the air suspension device 50 is an example of a predetermined value in this disclosure.

[0029] If the height H of the obstacle 14 is less than the maximum minimum ground clearance Hmax, the process proceeds from step 80 to step 82. In step 82, the control unit 44 controls the operation of the air suspension system 50 so that the vehicle height on the front wheel side rises to the maximum feasible vehicle height of the air suspension system 50. In step 84, the control unit 44 controls the operation of the air suspension system 50 so that the vehicle height on the rear wheel side rises to the maximum feasible vehicle height of the air suspension system 50. In step 86, the control unit 44 controls the drive control ECU 60 so that the drive torque applied to the rear wheels of the vehicle 10 by the MG 62 increases, and the process returns to step 70.

[0030] As a result of the processes described in steps 82 to 86 above, the body of the vehicle 10 changes from the steady state shown in Figure 4(A) to a rearward-tilted position as shown in Figure 4(B), where the side of the vehicle in the direction of travel is higher than the opposite side, and the minimum ground clearance at the front end of the vehicle body also increases. Therefore, when the obstacle 14 passes through the space below the vehicle body, it is possible to avoid the obstacle 14 coming into contact with the battery 12.

[0031] Furthermore, if the height H of the obstacle 14 is greater than or equal to the maximum minimum ground clearance Hmax, the obstacle 14 may come into contact with the battery 12 even if the vehicle body 10 is adjusted to the minimum ground clearance and posture shown in Figure 4(B). For this reason, if the height H of the obstacle 14 is greater than or equal to the maximum minimum ground clearance Hmax, the process proceeds from step 80 to step 88.

[0032] In step 88, the control unit 44 controls the operation of the air suspension system 50 so that the vehicle height on the front wheel side of the vehicle is lowered to the lowest possible vehicle height of the air suspension system 50. In step 90, the control unit 44 controls the operation of the air suspension system 50 so that the vehicle height on the rear wheel side of the vehicle is raised to the highest possible vehicle height of the air suspension system 50. Furthermore, in step 92, the control unit 44 controls the brake control ECU 64 so that the braking torque applied to the front wheels of the vehicle 10 by the brake system 66 is increased, and then returns to step 70.

[0033] As a result of the processes described in steps 88 to 92 above, the body of vehicle 10 changes from the steady state shown in Figure 5(A) to a forward-leaning posture as shown in Figure 5(B), where the side of the vehicle in the direction of travel is lower than the opposite side, and the minimum ground clearance at the front of the vehicle body is also reduced. Therefore, by preventing the obstacle 14 from colliding with the front bumper or other parts located at the front of the vehicle body, it is possible to avoid the obstacle 14 entering the space below the vehicle body and coming into contact with the battery 12.

[0034] As described above, in this embodiment, the battery protection device 20 includes a lidar 22 or camera 24 that detects obstacles 14 in the direction of travel of the vehicle 10, which has a battery 12 located below the floor of the vehicle body and is equipped with an air suspension system 50 that allows for vehicle height adjustment. When the control unit 44 determines that an obstacle 14 detected by the lidar 22 or camera 24 may come into contact with the battery 12, it controls the air suspension system 50 and the MG 62 or brake system 66 of the vehicle 10 to adjust the minimum ground clearance and attitude of the vehicle body. By adjusting the minimum ground clearance and attitude of the vehicle body, it is possible to suppress the obstacle 14 from coming into contact with the battery 12, and since it is not necessary to provide protective members around the battery 12 to protect the battery 12, an increase in the number of parts of the vehicle 10 can be suppressed.

[0035] Furthermore, in this embodiment, when the lidar 22 or camera 24 detects an obstacle 14 in the direction of travel of the vehicle 10, it detects the height H of the obstacle 14. The control unit 44 then determines that if the height H of the obstacle 14 detected by the lidar 22 or camera 24 is greater than or equal to the current minimum ground clearance of the vehicle body, the obstacle 14 may come into contact with the battery 12. This makes it possible to accurately determine whether or not the obstacle 14 may come into contact with the battery 12.

[0036] Furthermore, in this embodiment, the control unit 44 controls the air suspension system 50 so that the minimum ground clearance on the front and rear wheel sides of the vehicle 10 increases when the height H of the obstacle 14 detected by the lidar 22 or camera 24 is less than a predetermined value, and also increases the driving torque applied by the MG 62 to the rear wheels of the vehicle 10. As a result, the body of the vehicle 10 assumes a rearward tilt posture where the side of the vehicle 10 in the direction of travel is higher than the opposite side, and when the obstacle 14 with a height H less than a predetermined value passes through the space below the vehicle body, it is possible to avoid the obstacle 14 coming into contact with the battery 12.

[0037] Furthermore, in this embodiment, when the height of an obstacle 14 detected by the lidar 22 or camera 24 is greater than or equal to a predetermined value, the control unit 44 controls the air suspension system 50 so that the minimum ground clearance on the front wheel side of the vehicle 10 decreases and the minimum ground clearance on the rear wheel side of the vehicle 10 increases, and also increases the braking torque applied by the brake system 66 to the front wheels of the vehicle 10. As a result, the body of the vehicle 10 assumes a forward-leaning posture where the side of the vehicle 10 in the direction of travel is lower than the opposite side, and an obstacle 14 with a height H greater than or equal to a predetermined value collides with the front bumper or the like located at the front end of the vehicle 10 in the direction of travel, thereby preventing the obstacle 14 from entering the space below the vehicle body and coming into contact with the battery 12.

[0038] In the above embodiment, the case where the vehicle 10 is traveling in the forward direction was described, but in this disclosure, the vehicle 10 may be traveling in the reverse direction. When the vehicle 10 is traveling in the reverse direction, if an obstacle 14 is detected in the reverse direction of the vehicle 10, and the height H of the detected obstacle 14 is less than the maximum value Hmax of the minimum ground clearance achievable by the air suspension device 50, the minimum ground clearance on the front wheel side and the rear wheel side of the vehicle 10 is increased, and the vehicle body is controlled to tilt forward. Also, when the vehicle 10 is traveling in the reverse direction, if an obstacle 14 is detected in the reverse direction of the vehicle 10, and the height H of the detected obstacle 14 is greater than or equal to the maximum value Hmax of the minimum ground clearance achievable by the air suspension device 50, the minimum ground clearance on the front wheel side of the vehicle 10 is increased, the minimum ground clearance on the rear wheel side of the vehicle 10 is decreased, and the vehicle body is controlled to tilt backward. This makes it possible to suppress the obstacle 14 from coming into contact with the battery 12 even when the vehicle 10 is traveling in the reverse direction.

[0039] Furthermore, in the above embodiment, an air suspension system 50 capable of independently adjusting the height of all four wheels was described as an example of an active suspension system capable of adjusting the vehicle height, but this disclosure is not limited thereto. The active suspension system capable of adjusting the vehicle height may, for example, be configured to control the two front wheels and the two rear wheels simultaneously.

[0040] Furthermore, while the above embodiments described an example of an active suspension system with adjustable ride height in which an air suspension is applied, this disclosure is not limited thereto. An active suspension system with adjustable ride height may be, for example, an active suspension system that operates using hydraulic pressure supplied from a hydraulic power source.

[0041] Furthermore, in the above embodiments, an example of a predetermined value in this disclosure was described in which the maximum value Hmax, which is the minimum ground clearance achievable by the air suspension device 50, is applied. However, the predetermined value in this disclosure may be a value smaller than the maximum value Hmax.

[0042] Furthermore, although the above describes an embodiment in which the attitude / vehicle height control program 42 is pre-stored (installed) in the storage 36, the attitude / vehicle height control program 42 can also be provided in a form recorded on a non-temporary recording medium such as an HDD, SSD, or DVD. [Explanation of symbols]

[0043] 10 vehicles 12 batteries 14 Obstacles 20 Battery protection device 22. LIDA (detection unit) 24 Camera (detection unit) 30 Advanced safety integrated ECU 50. Air suspension system (active suspension system) 60 Drive Control ECU (Drive Unit) 62 MG (Drive Unit) 64. Brake control ECU (braking system) 66 Brake system (braking device)

Claims

1. A detection unit for detecting obstacles in the direction of travel of a vehicle equipped with an active suspension system that allows for ride height adjustment and has a battery located under the floor of the vehicle body, When the detection unit determines that the obstacle detected may come into contact with the battery, the control unit controls the active suspension system and the vehicle's drive system or braking system to adjust the minimum ground clearance and attitude of the vehicle body. A battery protection device for vehicles, including those mentioned above.

2. When the detection unit detects an obstacle in the direction of travel of the vehicle, it detects the height of the obstacle. The battery protection device for a vehicle according to claim 1, wherein the control unit determines that there is a possibility that the obstacle may come into contact with the battery when the height of the obstacle detected by the detection unit is greater than or equal to the current minimum ground clearance of the vehicle body.

3. The battery protection device for a vehicle according to claim 2, wherein the control unit controls the active suspension device so as to increase the minimum ground clearance on the front wheel side and the rear wheel side of the vehicle when the height of the obstacle detected by the detection unit is less than a predetermined value, and increases the driving torque applied by the drive unit to the rear wheel of the vehicle.

4. The battery protection device for a vehicle according to claim 2, wherein the control unit controls the active suspension device so that the minimum ground clearance on the front wheel side of the vehicle decreases and the minimum ground clearance on the rear wheel side of the vehicle increases when the height of the obstacle detected by the detection unit is greater than or equal to a predetermined value, and increases the braking torque applied by the braking device to the front wheels of the vehicle.

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