A method for controlling the steering of an electric vehicle while floating on water, and an electric vehicle

Abstract

The present application provides a steering control method for floating driving of an electric vehicle and an electric vehicle, which are applied to the technical field of electric vehicles to improve the steering efficiency of the electric vehicle during the steering process of floating driving of the electric vehicle. Among them, in the above-mentioned steering control method for floating driving, at the first moment when the electric vehicle is moving forward, the steering angle of the steering wheel of the electric vehicle is less than the first preset angle, driving the two front wheels of the electric vehicle to rotate. Then, at the second moment after the first moment, the steering angle of the steering wheel is increased to the first preset angle, and the rotation speed of the front wheel on the steering side is controlled to be less than the rotation speed of the front wheel on the other side. Based on this, when the electric vehicle is turning, it can provide the electric vehicle with a torque for yaw motion to the steering side, helping the electric vehicle to turn faster to improve the steering efficiency of the electric vehicle and reduce the design cost.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a method for controlling the steering of an electric vehicle while floating on water and the electric vehicle. Background Art

[0002] With the widespread use of electric vehicles, electric vehicles often encounter situations where they need to wade during their driving. When the water depth in the wading section is deep, the electric vehicle will be in a floating state. When the electric vehicle is in a floating state, the body of the electric vehicle is immersed in water, so it is necessary to adapt the steering control to help the electric vehicle quickly cross the water and choose a suitable place to go ashore. In order to solve the problem of steering control of electric vehicles in floating driving, existing solutions require additional hardware such as airbags or retractable propellers to control the steering through left and right vortexes, but these solutions have a slow response, low steering efficiency and high cost. Therefore, providing a method for steering control of electric vehicles in floating driving has become an urgent problem to be solved. Summary of the invention

[0003] The present application provides a steering control method for floating driving of an electric vehicle and an electric vehicle, which are used to improve the steering efficiency of the electric vehicle during floating driving and reduce the cost.

[0004] In order to achieve the above objectives, this application provides the following technical solutions.

[0005] In the first aspect, the present application provides a steering control method for floating driving of an electric vehicle, which is used to control the driving direction of the electric vehicle during floating driving, and the steering control method for floating driving comprises: at a first moment when the electric vehicle is driving forward, the steering angle of the electric vehicle's steering wheel turning to the left is less than a first preset angle, and the two front wheels of the electric vehicle are driven to rotate forward. At a second moment after the first moment, the steering angle of the steering wheel turning to the left increases to the first preset angle, and the rotation speed of the left front wheel of the electric vehicle is controlled to be less than the rotation speed of the right front wheel of the electric vehicle.

[0006] When the electric vehicle is traveling forward and the angle at which the steering wheel of the electric vehicle turns to the left is less than the first preset angle during the electric vehicle's floating driving, it indicates that the electric vehicle does not need to turn. At this time, controlling the two front wheels of the electric vehicle to rotate forward can drive the electric vehicle forward. When the angle at which the steering wheel of the electric vehicle turns to the left increases to the first preset angle, it indicates that the electric vehicle needs to turn left. At this time, the two front wheels of the electric vehicle rotate forward to drive the electric vehicle forward. In addition, controlling the rotation speed of the left front wheel of the electric vehicle to be less than the rotation speed of the right front wheel of the electric vehicle can make the power of the right front wheel greater than the power of the left front wheel, thereby providing the electric vehicle with a torque for yaw motion to the left, helping the electric vehicle to turn faster, so as to improve the steering efficiency of the electric vehicle during floating driving. The technical solution of the present application does not require the additional installation of other air cushions and other devices, is simple and practical, and enables costs to be controlled.

[0007] Based on the same technical principle, the electric vehicle can also refer to the above method to improve the steering efficiency of the electric vehicle when turning right and moving forward during floating water driving. In addition, the electric vehicle can also control the two front wheels to rotate in the opposite direction when driving backward during floating water driving, and control the speed difference between the left front wheel and the right front wheel according to the steering direction of the steering wheel according to the above technical principle, thereby improving the steering efficiency of the electric vehicle during floating water driving.

[0008] In one embodiment, the above-mentioned floating driving steering control method also includes: at a third moment after the second moment, the steering wheel turning angle to the left is increased to a second preset angle, increasing the speed difference between the left front wheel of the electric vehicle and the right front wheel of the electric vehicle.

[0009] When the steering wheel turns leftward and the angle increases to the second preset angle, it indicates that the turning range of the electric vehicle becomes larger. At this time, on the basis of controlling the rotation speed of the left front wheel of the electric vehicle to be less than the rotation speed of the right front wheel of the electric vehicle, increasing the rotation speed difference between the left front wheel of the electric vehicle and the right front wheel of the electric vehicle can further increase the torque of the left yaw motion and help the electric vehicle turn faster. The left and right wheel speed difference increases continuously with the increase of the steering wheel angle, which can quickly respond to the steering demand and speed up the steering speed.

[0010] Based on the same technical principle, when the steering wheel turns rightward to a second preset angle, the speed difference between the left front wheel of the electric vehicle and the right front wheel of the electric vehicle can be increased on the basis of controlling the speed of the left front wheel of the electric vehicle to be less than the speed of the right front wheel of the electric vehicle. In addition, when the steering wheel turns rightward to a second preset angle during the electric vehicle's floating driving process, the speed difference between the left front wheel of the electric vehicle and the right front wheel of the electric vehicle can also be increased.

[0011] In one embodiment, the above-mentioned floating driving steering control method further includes: after the second moment, controlling the brake device of the electric vehicle to brake the left front wheel of the electric vehicle. After the third moment, controlling the brake device of the electric vehicle to increase the braking force on the left front wheel of the electric vehicle.

[0012] In the above manner, when the steering wheel is turned to the left to move forward during the electric vehicle floating on water, the braking force output by the braking device of the left front wheel is adjusted by the steering wheel angle, so that the rotation speed of the left front wheel can be less than the rotation speed of the right front wheel, thereby providing the electric vehicle with a torque for left yaw movement, helping the electric vehicle to turn faster.

[0013] Based on the same technical principle, when the electric vehicle turns right and moves forward during the floating driving process, the braking force output by the brake device of the left front wheel can be adjusted by adjusting the steering wheel angle to adjust the speed difference between the left front wheel and the right front wheel, thereby better controlling the turning rate of the electric vehicle. In addition, when the electric vehicle is traveling backward during the floating driving process, on the basis of controlling the two front wheels to rotate in the opposite direction, the speed difference between the left front wheel and the right front wheel can also be adjusted based on the same technical principle, thereby helping the electric vehicle to turn faster.

[0014] In addition, after the second moment, the driving motor of the electric vehicle can also be controlled to increase the driving torque of the left front wheel to adjust the speed difference between the left front wheel and the right front wheel. After the third moment, the driving motor of the electric vehicle is controlled to further increase the driving torque of the left front wheel to increase the speed difference between the left front wheel and the right front wheel.

[0015] In one embodiment, the above-mentioned floating driving steering control method further includes: at a fourth moment after the third moment, the steering angle of the steering wheel turning left is increased to a third preset angle, and the left rear wheel of the electric vehicle is controlled to rotate in the opposite direction.

[0016] When the steering wheel turns leftwards and the steering wheel turns to the third preset angle, it indicates that the steering wheel has turned to the maximum angle or near the maximum angle. At this time, by controlling the left rear wheel of the electric vehicle to rotate in the opposite direction, the power provided by the left wheel during the electric vehicle's forward movement can be further reduced from the power provided by the right wheel, thereby increasing the torque of the left yaw motion and helping the electric vehicle to turn faster.

[0017] In one embodiment, the above-mentioned floating driving steering control method further includes: at the second moment, controlling the rear wheels of the electric vehicle to turn right to a first preset rear wheel turning angle and controlling the right rear wheel to rotate forward.

[0018] After the electric vehicle moves forward and the steering wheel turning angle of the electric vehicle increases to the left to a first preset angle, on the basis of controlling the rotation speed of the left front wheel of the electric vehicle to be less than the rotation speed of the right front wheel of the electric vehicle, controlling the rear wheels of the electric vehicle to turn right to the first preset rear wheel angle and controlling the right rear wheel to rotate forward can provide a torque for the rear end of the electric vehicle to yaw to the right, thereby helping the electric vehicle to complete the turn faster.

[0019] In one embodiment, the above-mentioned floating driving steering control method also includes: at a third moment after the second moment, the steering wheel turning angle to the left increases to a third preset angle, and the rear wheels of the electric vehicle are controlled to turn right to increase to a second preset rear wheel angle.

[0020] In the above manner, by increasing the speed difference between the left front wheel and the right front wheel of the electric vehicle and increasing the turning angle of the rear wheel to the right, the torque provided to the rear end of the electric vehicle for the right yaw movement can be increased, thereby helping the electric vehicle to complete the turn faster.

[0021] In one embodiment, the above-mentioned floating driving steering control method further includes: at a fourth moment after the third moment, the steering wheel turns left at a third preset angle, and controls the left rear wheel of the electric vehicle to rotate forward. By controlling the left rear wheel of the electric vehicle to rotate forward, the thrust of the electric vehicle when turning can be increased during the process of the electric vehicle floating on water, thereby helping the electric vehicle to complete the steering faster.

[0022] In a second aspect, the present application also provides a floating driving steering control method for an electric vehicle, the floating driving steering control method is used to control the driving direction of the electric vehicle during floating driving, the floating driving steering control method comprises: at a fifth moment when the electric vehicle is traveling backwards, the steering angle of the electric vehicle's steering wheel turning to the left is less than a fourth preset angle, driving the two front wheels of the electric vehicle to rotate. At a sixth moment after the fifth moment, the steering angle of the steering wheel turning to the left increases to the fourth preset angle, and the speed difference between the right front wheel of the electric vehicle and the left front wheel of the electric vehicle is controlled to be the first speed difference.

[0023] When the electric vehicle is traveling on water and the electric vehicle is traveling backward, it indicates that the electric vehicle is reversing. When the turning angle of the steering wheel of the electric vehicle to the left is less than the fourth preset turning angle, it indicates that the electric vehicle does not need to turn, and at this time, controlling the two front wheels of the electric vehicle to rotate in the opposite direction can drive the electric vehicle to travel backward. When the turning angle of the steering wheel to the left increases to the fourth preset turning angle when the electric vehicle is traveling backward, it indicates that the electric vehicle needs to turn right and reverse. At this time, the two front wheels of the electric vehicle are rotating in the opposite direction to drive the electric vehicle to travel backward. In addition, controlling the rotation speed of the left front wheel of the electric vehicle to be less than the rotation speed of the right front wheel of the electric vehicle can provide the electric vehicle with a torque for yaw motion to the left, helping the electric vehicle to turn faster, so as to improve the steering efficiency of the electric vehicle during the process of traveling on water and the electric vehicle.

[0024] In one embodiment, the above-mentioned floating driving steering control method further includes: at a seventh moment after the sixth moment, the steering wheel turns left at an angle increased to a fifth preset angle, and the speed difference between the right front wheel of the electric vehicle and the left front wheel of the electric vehicle is controlled to be a first speed difference. At an eighth moment after the seventh moment, the steering wheel turns left at an angle increased to a sixth preset angle, and the speed difference between the right front wheel of the electric vehicle and the left front wheel of the electric vehicle is controlled to be a second speed difference, and the second speed difference is greater than the first speed difference.

[0025] By the above method, when the electric vehicle is reversing during the floating driving process, as the steering wheel turns to the left, the speed difference between the right front wheel and the left front wheel can be increased in a step-by-step manner, so as to more conveniently control the steering process of the electric vehicle floating driving. The speed difference between the left and right wheels increases in a step-by-step manner as the steering wheel angle increases, which can reduce the frequency of changes in the left and right wheel speeds, and is conducive to maintaining the stability of the vehicle body during steering.

[0026] Based on the same technical principle, when the electric vehicle is traveling backward, as the steering wheel turns right, the speed difference between the right front wheel and the left front wheel can be increased in a step-wise manner. In addition, when the electric vehicle is traveling forward on water, as the steering wheel turns right, the speed difference between the right front wheel and the left front wheel can be increased in a step-wise manner, thereby helping the electric vehicle to turn faster.

[0027] In one embodiment, the above-mentioned floating driving steering control method further includes: after the sixth moment, controlling the brake device of the electric vehicle to brake the left front wheel of the electric vehicle. After the eighth moment, controlling the brake device of the electric vehicle to increase the braking force on the left front wheel of the electric vehicle.

[0028] In the above manner, when the steering wheel is turned left to reverse during the floating driving of the electric vehicle, the braking force output by the braking device on the left front wheel can be adjusted according to the steering wheel angle to adjust the speed difference between the left front wheel and the right front wheel, so as to timely adjust the steering rate of the electric vehicle.

[0029] In one embodiment, the above-mentioned floating driving steering control method further includes: at a ninth moment after the eighth moment, when the steering wheel turns left at a seventh preset angle, controlling the left rear wheel of the electric vehicle to rotate forward. During the backward driving and steering process of the electric vehicle, the forward rotation of the left rear wheel of the electric vehicle can reduce the power on the left side of the electric vehicle, thereby increasing the torque of the electric vehicle's yaw motion to the left, thereby helping the electric vehicle to turn faster.

[0030] In one embodiment, the above-mentioned floating driving steering control method further includes: at the sixth moment, controlling the rear wheels of the electric vehicle to turn right to a third preset rear wheel angle and controlling the right rear wheel to rotate in the opposite direction. When the electric vehicle is traveling backward during floating driving, the steering wheel turns left so that the two front wheels turn left, and the electric vehicle can reverse to the left. On this basis, controlling the rear wheels to turn right while controlling the right rear wheel to rotate in the opposite direction can provide a torque for the rear end of the vehicle to yaw to the left, which can reduce the turning radius, thereby helping the electric vehicle to turn faster.

[0031] In one embodiment, the above-mentioned floating driving steering control method further includes: at a ninth moment after the eighth moment, controlling the rear wheels of the electric vehicle to rotate in the opposite direction.

[0032] In the above manner, when the electric vehicle is traveling backwards during floating water driving and the steering wheel turns left at an increased angle, the speed difference between the left front wheel and the right front wheel increases, and the electric vehicle has not yet completed the turning. By controlling the rear wheels of the electric vehicle to rotate in the opposite direction, the power of the electric vehicle during turning can be increased, thereby helping the electric vehicle to turn faster.

[0033] In one embodiment, the above-mentioned floating driving steering control method further includes: at a sixth moment, controlling the electric vehicle to increase the height of the left side vehicle body.

[0034] When the electric vehicle is traveling on water, the steering wheel turns left at an angle that increases to a fourth preset angle, indicating that the electric vehicle needs to turn left. When the electric vehicle turns left, the body of the electric vehicle will tilt to the left, causing the wading depth on the left side to increase. At this time, by raising the height of the left body, the body of the electric vehicle can be prevented from tilting to the left, thereby helping the electric vehicle to maintain balance when turning.

[0035] In one embodiment, the above-mentioned floating driving steering control method further includes: when waves are detected on the right side of the electric vehicle during floating driving, controlling the electric vehicle to raise the height of the left side of the vehicle body to reduce the impact of the waves on the vehicle body. Based on the same technical principle, when there are waves on one side of the electric vehicle, the height of the vehicle body on the other side can be controlled to reduce the impact of the wave impact on the balance of the electric vehicle.

[0036] In a third aspect, the present application provides an electric vehicle, which uses the floating driving steering control method provided in the first aspect and the second aspect to achieve floating driving steering.

[0037] In one embodiment, the electric vehicle uses the controller on its vehicle to use the floating driving steering control method provided by the first aspect and the second aspect to achieve floating driving steering, which can quickly achieve floating driving steering, flexibly respond to various floating driving situations, and can quickly select a suitable location to land on the shore after the floating driving ends, thereby enhancing the good driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0039] Figure 2 Another schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0040] Figure 3 Another schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0041] Figure 4 Another schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0042] Figure 5 Another schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0043] Figure 6 Another schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0044] Figure 7 Another schematic diagram of an electric vehicle provided in an embodiment of the present application;

[0045] Figure 8 A schematic diagram of a floating driving steering control method provided in an embodiment of the present application;

[0046] Fig. 9 Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application;

[0047] Fig.10Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application;

[0048] Fig.11 Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application;

[0049] Fig.12 Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application;

[0050] Fig.13 Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application;

[0051] Fig.14 Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application;

[0052] Fig.15 Another schematic diagram of the floating driving steering control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0054] It should be noted that "in one embodiment" in this application is used to indicate an example, illustration or description. The solution described as "in one embodiment" in this application should not be interpreted as being more preferred or more advantageous than the solutions of other embodiments. Specifically, the use of "in one embodiment" is intended to present the inventive concept of this application in a specific way.

[0055] During the driving process of the vehicle, wading is often encountered. Among them, when the water depth of the road section where the vehicle is driving exceeds the wheels of the vehicle, it will have a serious impact on driving safety. However, traditional fuel vehicles can easily be unable to drive due to water in the air intake pipe when wading, which seriously affects the personal safety of the people in the car. With the continuous development of electric vehicles, the dependence of traditional fuel vehicles on air intake has been broken away, which has reduced the difficulty of the application and promotion of amphibious functions on waterways. When the electric vehicle is in a floating state, the body of the electric vehicle is immersed in water, so it is necessary to adapt the steering control to help the electric vehicle quickly cross the water and choose a suitable place to land. In order to solve the problem of steering control of electric vehicles in floating driving, the existing solutions need to add additional hardware such as airbags or retractable propellers to control the steering through the left and right vortices. The relevant technology integrates airbag components on the vehicle floor. When the electric vehicle is floating on water, the airbag is inflated to generate buoyancy. At the same time, a propeller will be extended from the tire, and the propeller will be driven by the electric drive assembly to achieve vehicle floating. However, these solutions have a slow response, which affects the steering efficiency and adds additional costs.

[0056] In order to improve the steering efficiency of an electric vehicle during floating driving without increasing the cost, an embodiment of the present application provides a floating driving steering control method for an electric vehicle and an electric vehicle. The floating driving steering control method drives the wheels of the electric vehicle to rotate when the steering wheel angle is small or the steering wheel is not moving during the floating driving of the electric vehicle, so as to drive the electric vehicle to drive. Among them, the wheels rotate forward when the electric vehicle is driving forward, and the wheels rotate reversely when the electric vehicle is driving backward. The forward rotation here refers to the rotation of the wheels of the electric vehicle toward the front of the vehicle, and the reverse rotation refers to the rotation of the wheels of the electric vehicle toward the rear of the vehicle. Then, when the steering wheel angle increases to a first preset angle, the speed difference of the wheels on both sides is controlled according to the steering direction of the steering wheel, thereby providing a yaw motion torque for the electric vehicle, helping the electric vehicle to turn faster to improve the steering efficiency of the electric vehicle. Similarly, when reversing, the speed difference of the wheels on both sides can also be controlled according to the steering direction of the steering wheel to achieve reverse steering.

[0057] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0058] Figure 1 A schematic diagram of an electric vehicle provided in an embodiment of the present application. Figure 1 As shown, the electric vehicle 10 generally includes a drive system 100, a brake system 200, a power battery 300, a controller 400 and a suspension system 500. The drive system 100, the brake system 200, the suspension system 5400, and the controller 400 are connected in communication and exchange signals through a communication bus. Among them, the communication bus includes a controller area network (CAN) bus, a local interconnect network (LIN) bus, a high-speed fault-tolerant network protocol (flexray) or other types of buses, which are not limited here. In addition, the drive system 100 is used to drive the wheels of the electric vehicle 10 to drive the electric vehicle 10. The brake system 200 is used to brake the wheels of the electric vehicle 10 to slow down the electric vehicle 10. The power battery 300 is used to power the drive system 100, the brake system 200, the controller 400 and the suspension system 500. When the electric vehicle 10 is in a floating state, the controller 400 can control the driving system 100 , the braking system 200 , and the suspension system 500 to control the electric vehicle 10 to float on water.

[0059] In the embodiment provided in the present application, the suspension system 500 is an air suspension system or an active suspension system. The active suspension system is a suspension system with intelligent closed-loop electronic control, which can automatically adjust the stiffness, damping and body height of each wheel suspension in advance according to the feedback of sensor signals such as vehicle speed, load, turning and bumping, thereby reducing the bumps and roll of the vehicle body, taking into account the smoothness and handling stability of the vehicle. The air suspension system is a suspension system that uses compressed air as a spring element. It can adjust the hardness of the spring by controlling the air compressor and the exhaust valve according to the road conditions and the signal of the distance sensor, thereby adjusting the body height, enhancing the body stability at high speed and the passability of complex road conditions.

[0060] Figure 2 Another schematic diagram of an electric vehicle provided in an embodiment of the present application. Figure 2 As shown in FIG. 1 , in one embodiment, the drive system 100 includes a motor controller 110 (MCU), a drive motor 120 and a reducer 130. Figure 2 As shown, the motor controller 110 is used to receive the direct current outputted by the power battery 300 and output the alternating current to control the drive motor 120 to output the driving torque. The driving torque outputted by the drive motor 120 drives the wheels of the electric vehicle 10 through the reducer 130 .

[0061] The brake system 200 includes a plurality of brake devices 210, and the plurality of brake devices 210 are used to brake a plurality of wheels of the electric vehicle 10. In one embodiment, the brake device 210 may be an electric hydraulic brake (EHB) device or an electric mechanical brake (EMB) device.

[0062] In one embodiment, Figure 2 As shown, the electric vehicle 10 further includes a speed measuring unit 140. The speed measuring unit 140 is used to detect the speed of the wheel as the driving wheel in the electric vehicle. The controller 400 can control the speed difference of two wheels on the same axle through the speed of the wheel detected by the speed measuring unit 140. The speed measuring unit 140 is a speed sensor or a rotary transformer.

[0063] In one embodiment, Figure 2 As shown, the electric vehicle 10 further includes an inertial measurement unit 150. The inertial measurement unit 150 can detect the body roll angle of the electric vehicle 10, and the controller 400 can control the suspension system 500 to adjust the body height through the body roll angle of the electric vehicle 10 collected by the inertial measurement unit 150.

[0064] In one embodiment, Figure 2 As shown, the speed sensor 140 and the inertial measurement unit 150 are connected to the controller 400 through the brake system 200. Of course, the speed sensor 140 and the inertial measurement unit 150 can also be directly connected to the controller 400 through a communication bus or connected to the controller 400 through the drive system 100.

[0065] In one embodiment, the electric vehicle 10 further includes a rear-wheel steering system 600. When the electric vehicle 10 includes the rear-wheel steering system 600, in addition to the two front wheels of the electric vehicle 10 turning as the steering wheel turns, the controller 400 also controls the rear-wheel steering system 600 to drive the two rear wheels to turn. When the electric vehicle turns, the steering direction of the two rear wheels can be opposite to the steering direction of the two front wheels, so that the yaw direction of the rear of the electric vehicle is opposite to the steering direction of the steering wheel, which helps the electric vehicle 10 turn faster.

[0066] In one embodiment, the electric vehicle 10 further includes a plurality of cameras 170, and the cameras 170 detect water wave signals around the electric vehicle 10 when the electric vehicle 10 is floating on water. The controller 400 controls the suspension system 500 to adjust the vehicle height according to the water wave signals.

[0067] The electric vehicle 10 may also include other on-board electrical components, such as a window controller, an air intake valve in the air intake passage of the passenger compartment, etc. The window controller is used to open and close the windows and sunroof of the electric vehicle, and the air intake valve in the air intake passage of the passenger compartment is used to open or close the air intake passage. Of course, the electric vehicle 10 may also include more types of on-board electrical components, which will not be described in detail in the embodiments of the present application.

[0068] The electric vehicle 10 comprises a controller 400 and one or more drive systems 100. The controller 400 is used to control the voltage of the AC power output by the motor controller 110 in the drive system 100 according to the indication signal of the accelerator pedal to control the drive motor 120 to output the drive torque.

[0069] In one embodiment, the controller 400 is a central controller or a vehicle control unit (VCU) in the electric vehicle 10 .

[0070] In one embodiment, the controller 400 is a domain controller (DCU) in the electric vehicle 10 .

[0071] In the electric vehicle 10, the number of drive systems 100 is adjusted according to the drive mode of the electric vehicle 10. The drive modes of the electric vehicle 10 include front single drive, rear single drive, front double drive, rear double drive, front single drive + rear single drive, front single drive + rear double drive, front double drive + rear single drive and distributed four-wheel drive.

[0072] Figure 3 Another schematic diagram of an electric vehicle provided in an embodiment of the present application. In one embodiment, the two wheels corresponding to the front axle 220 of the electric vehicle 10 are the left front wheel FL and the right front wheel FR, and the two wheels corresponding to the rear axle 230 of the electric vehicle 10 are the left rear wheel RL and the right rear wheel RR. Figure 3 As shown, when the electric vehicle 10 is driven in a front single-wheel drive mode, the electric vehicle 10 includes a drive system 100. The drive system 100 is used to drive the left front wheel FL and the right front wheel FR on the front axle 220 of the electric vehicle 10. In addition, the electric vehicle 10 includes four brake devices 210. Among them, two brake devices 210 are respectively used to brake the left front wheel FL and the right front wheel FR of the electric vehicle 10. The other two brake devices 210 are respectively used to brake the left rear wheel RL and the right rear wheel RR of the electric vehicle 10.

[0073] Similarly, when the electric vehicle 10 is driven in a rear single-wheel drive mode, the drive system 100 is used to drive the left rear wheel RL and the right rear wheel RR of the electric vehicle 10 .

[0074] Figure 4 Another schematic diagram of an electric vehicle provided in an embodiment of the present application. In one embodiment, when the electric vehicle 10 is driven by front dual-wheel drive or rear dual-wheel drive, the electric vehicle 10 includes two drive systems 100. The two drive systems 100 are respectively used to drive two wheels on the same axle of the electric vehicle 10. The two wheels are the left front wheel FL and the right front wheel FR of the electric vehicle 10, or the two wheels are the left rear wheel RL and the right rear wheel RR of the electric vehicle 10. Figure 4 As shown, when the electric vehicle 10 is driven by front dual-drive, Figure 3 The difference compared to the present embodiment is that the two drive systems 100 are respectively used to drive the left front wheel FL and the right front wheel FR of the electric vehicle 10, so that the left front wheel FL and the right front wheel FR are independently controlled. Similarly, when the electric vehicle 10 is driven in a rear-front dual-drive mode, the two drive systems 100 are respectively used to drive the left rear wheel RL and the right rear wheel RR of the electric vehicle 10.

[0075] Figure 5 Another schematic diagram of an electric vehicle provided in an embodiment of the present application. In one embodiment, as Figure 5As shown in FIG. 1 , when the electric vehicle 10 is driven by a front single drive + a rear single drive, the electric vehicle 10 includes two drive systems 100. Figure 3 In addition to driving the left front wheel FL and the right front wheel FR of the electric vehicle 10 by one driving system 100, the present embodiment also drives the left rear wheel RL and the right rear wheel RR of the electric vehicle 10 by another driving system 100.

[0076] Figure 6 Another schematic diagram of an electric vehicle provided in an embodiment of the present application. In one embodiment, as Figure 6 As shown in FIG. 1 , when the electric vehicle 10 is driven by a front single drive + rear dual drive mode, the electric vehicle 10 includes three drive systems 100. Figure 3 The difference compared to the present embodiment is that: on the basis of one drive system 100 being used to drive the left front wheel FL and the right front wheel FR of the electric vehicle 10, the other two drive systems 100 are respectively used to drive the left rear wheel RL and the right rear wheel RR of the electric vehicle 10, so that the left rear wheel RL and the right rear wheel RR can be independently controlled.

[0077] Figure 7 Another schematic diagram of an electric vehicle provided in an embodiment of the present application. In one embodiment, as Figure 7 As shown, when the electric vehicle 10 is driven in a distributed four-wheel drive mode, the electric vehicle 10 includes four drive systems 100. Figure 3 The difference compared with the present embodiment is that the first drive system 100 is used to drive the left rear wheel RL of the electric vehicle 10, and the second drive system 100 is used to drive the right rear wheel RR of the electric vehicle 10. The third drive system 100 is used to drive the left front wheel FL of the electric vehicle 10, and the fourth drive system 100 is used to drive the right front wheel FR of the electric vehicle 10.

[0078] When the water depth of the road section where the electric vehicle 10 is traveling exceeds the wheels of the electric vehicle, the electric vehicle 10 can start the floating driving mode. Among them, the floating driving mode can be automatically started in the process of the tire gradually leaving the road surface after the electric vehicle detects that the water depth of the driving section exceeds the height of the wheel, or it can be started after the driver manually turns on the floating driving mode. After the electric vehicle 10 starts the floating driving mode, the electric vehicle 10 controls the window controller through the controller 400 to close the window and open the sunroof as needed. In addition, the controller 400 also controls the low water level air intake passage of the passenger compartment to be closed to avoid water entering the passenger compartment. Then, after the driver steps on the accelerator pedal, the controller 400 controls the drive system 100 to drive the wheels of the electric vehicle 10 to rotate to drive the electric vehicle 10 to float on the water. Among them, during the floating driving process of the electric vehicle 10, the rotation speed of the left wheel is controlled to be less than the rotation speed of the right wheel, so that the power provided by the right wheel can be greater than the power provided by the left wheel, thereby providing the electric vehicle 10 with a torque for left yaw motion. When the electric vehicle 10 is floating on water, controlling the rotation speed of the right wheel to be lower than that of the left wheel can make the power provided by the left wheel greater than that provided by the right wheel, thereby providing the electric vehicle 10 with a torque for rightward yaw motion.

[0079] Based on the above principle, the embodiment of the present application provides a method for controlling the steering of the electric vehicle 10 when the steering wheel steering angle is less than the first preset angle (i.e., the electric vehicle does not need to turn or the steering amplitude is small), such as when the steering angle is less than 3 degrees, the two front wheels of the electric vehicle 10 are controlled to rotate, thereby driving the electric vehicle 10 to move forward or reverse. Then, when the steering wheel steering angle of the electric vehicle 10 increases to the second preset angle when the electric vehicle is floating on water (i.e., when the electric vehicle needs to turn and the steering amplitude is large), the rotation speed of the front wheel on one side of the steering direction is controlled to be less than the rotation speed of the front wheel on the other side, so that the power provided by the front wheel on one side of the steering direction is less than the power provided by the wheel on the other side, thereby providing the electric vehicle 10 with a torque for yaw movement in the steering direction, helping the electric vehicle 10 to turn faster.

[0080] In one embodiment, the controller 400 controls the speed difference between the front wheel on one side of the steering direction and the front wheel on the other side to increase as the steering angle of the steering wheel increases, thereby timely adjusting the torque of the electric vehicle 10 to yaw in the steering direction, so as to improve the steering efficiency of the electric vehicle 10 when the steering angle of the steering wheel increases. The left and right wheel speed difference increases continuously as the steering wheel angle increases, which can quickly respond to steering needs in real time and speed up the steering speed.

[0081] In one embodiment, when the steering wheel angle reaches the maximum angle and the electric vehicle 10 has not completed the turn, the controller 400 can control the rear wheels on the steering direction side to rotate in the opposite direction of the front wheels, thereby reducing the power on the steering direction side, further increasing the torque of the electric vehicle 10 yaw motion in the steering direction, and helping the electric vehicle 10 complete the turn faster.

[0082] In one embodiment, when the steering angle of the steering wheel increases to a second preset angle, the controller 400 can also control the rear-wheel steering system 600 to drive the rear wheels to turn to the side opposite to the steering direction and control the two rear wheels to rotate in the direction of the front wheels, thereby providing the electric vehicle with a torque to help the rear end of the vehicle to yaw, helping the electric vehicle to turn faster.

[0083] For ease of understanding, the electric vehicle floating control method, controller and electric vehicle provided by the embodiments of the present application are described below in conjunction with the forward driving process and the backward driving process of the electric vehicle 10 floating on water.

[0084] Figure 8 A schematic diagram of a floating driving steering control method provided in an embodiment of the present application. Figure 8 As shown, the first moment T1 represents that the steering wheel turning angle of the electric vehicle 10 when the electric vehicle 10 is moving forward during the floating driving process is less than the first preset angle θ1, and the second moment T2 represents that the steering wheel turning angle of the electric vehicle 10 when the electric vehicle 10 is moving forward during the floating driving process increases to the first preset angle θ1.

[0085] At the first moment T1 when the electric vehicle 10 is traveling forward, the angle of the steering wheel of the electric vehicle turning left is less than the first preset angle θ1, indicating that the electric vehicle 10 does not need to turn or only needs to slightly adjust the driving direction. At this time, the controller 400 controls the corresponding drive motor in the drive system 100 to drive the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate forward, which can drive the electric vehicle 10 to travel forward. Among them, at the first moment T1, the difference between the rotation speed n1 of the left front wheel FL and the rotation speed n2 of the right front wheel FR is within a very small range, such as less than n2*3%.

[0086] After the first moment T1, when the driver continues to turn the steering wheel to the left to increase the steering wheel's left-turning angle to the first preset angle θ1, it indicates that the electric vehicle needs to turn left. At this time, the left front wheel FL and the right front wheel FR rotate forward and turn left, which can provide the front of the electric vehicle with forward driving power and torque for yaw motion to the left, driving the electric vehicle 10 to turn left and move forward. However, when the rotation speed of the left front wheel FL is substantially the same as that of the right front wheel FR, the electric vehicle 10 cannot turn or can only turn the electric vehicle through the power provided by the forward rotation of the left front wheel FL and the right front wheel FR, resulting in a slower steering speed of the electric vehicle. Therefore, it is necessary to control and increase the rotation speed difference between the left front wheel FL and the right front wheel FR to increase the torque for yaw motion provided to the electric vehicle 10, thereby helping the electric vehicle 10 to turn faster.

[0087] In one embodiment, when the left turning angle of the steering wheel increases to a first preset angle at a second moment T2 after the first moment T1, the controller 400 automatically controls the braking device of the electric vehicle 10 to output a braking force F1 to brake the left front wheel FL of the electric vehicle 10, so that the rotation speed n1 of the left front wheel FL of the electric vehicle 10 is less than the rotation speed n2 of the right front wheel FR, thereby providing the electric vehicle 10 with additional torque for left yaw motion, helping the electric vehicle 10 to turn left faster.

[0088] After the second moment T2, the driver continues to turn the steering wheel to the left to increase the steering angle of the steering wheel to the left and the steering wheel angle has not reached the maximum angle, indicating that the driver needs to drive the electric vehicle 10 to turn at a larger steering angle. At this time, the torque provided to the electric vehicle 10 for the left yaw motion is larger in order to increase the steering angle of the electric vehicle 10 more quickly. However, when the speed difference between the rotation speed n1 of the left front wheel LF and the rotation speed n2 of the right front wheel FR remains unchanged, the torque provided by the electric vehicle 10 for the left yaw motion will not change. Therefore, it is necessary to gradually increase the speed difference between the rotation speed n1 of the left front wheel FL and the rotation speed n2 of the right front wheel FR to increase the torque of the electric vehicle 10 for the left yaw motion, so as to ensure that the electric vehicle 10 can quickly complete the steering.

[0089] In one embodiment, when the left turning angle of the steering wheel increases to the second preset turning angle θ2 but does not reach the maximum turning angle at the third moment T3 after the second moment T2, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged, and controls the braking device of the electric vehicle 10 to increase the braking force F1 on the left front wheel FL, thereby increasing the rotation speed difference between the left front wheel FL and the right front wheel FR, providing the electric vehicle 10 with a larger torque for left yaw motion, and helping the electric vehicle 10 to turn faster.

[0090] After the third moment T3, the driver continues to turn the steering wheel to the left to increase the steering angle of the steering wheel to the maximum steering angle or close to the maximum steering angle, and the electric vehicle 10 needs to turn and drive at a larger steering angle. At this time, the controller 400 controls the braking force output by the braking device of the electric vehicle 10 to the left front wheel FL to reach the maximum, so that the speed difference between the left front wheel FL and the right front wheel FR reaches the maximum value, and the speed difference between the left front wheel FL and the right front wheel FR cannot be further increased to increase the torque of the left yaw motion provided to the electric vehicle 10, which affects the steering efficiency of the electric vehicle 10.

[0091] In one embodiment, Figure 8 As shown, at the fourth moment T4 after the third moment T3, the left turning angle of the steering wheel increases to the third preset angle θ3 (i.e., the maximum turning angle or close to the maximum turning angle of the steering wheel), and the controller 400 controls the rotation speed n2 of the right front wheel FR and the braking force F1 of the left front wheel FL to remain unchanged and controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate in the opposite direction, so as to reduce the forward power provided by the left wheel to the electric vehicle 10, so that the power provided by the right wheel of the electric vehicle 10 is greater than the power provided by the left wheel, and at the same time, the rotation speed difference between the left and right wheels is further increased, thereby further increasing the torque provided for the electric vehicle 10 to provide for the left yaw motion, and helping the electric vehicle 10 to turn faster.

[0092] Among them, Figure 8 As shown, when the steering wheel turns leftward at a third preset angle θ3, the controller 400 immediately controls the drive motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate in the opposite direction. Based on this, the power provided by the left wheel to the electric vehicle can be quickly reduced by the reverse rotation of the left rear wheel RL, and the speed difference between the left and right wheels is further increased, thereby increasing the torque provided to the electric vehicle 10 for the leftward yaw motion, and helping the electric vehicle 10 to turn faster.

[0093] In one embodiment, the controller 400 controls the left rear wheel RL to rotate in the opposite direction after the steering wheel turns leftward and increases to the third preset angle θ3 for a period of time. Based on this, controlling the left rear wheel RL to rotate in the opposite direction after the electric vehicle 10 has turned a certain angle can make the left rear wheel RL rotate in the opposite direction at a lower speed, so that the electric vehicle 10 can turn more smoothly.

[0094] In one embodiment, the controller 400 can control the drive motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate in the opposite direction at the fourth moment T4, and can also control the drive motor corresponding to the right rear wheel RR to drive the right rear wheel RR to rotate forward, thereby increasing the torque of the electric vehicle to yaw to the left. In the specific implementation, the left rear wheel RL is controlled to rotate in the opposite direction while the right rear wheel RR is controlled to rotate forward; or, the left rear wheel RL is controlled to rotate in the opposite direction first, and then the right rear wheel RR is controlled to rotate forward; or, the right rear wheel RR is controlled to rotate forward first, and then the left rear wheel RL is controlled to rotate in the opposite direction.

[0095] In one embodiment, at time T41 after the fourth time T4, the driver operates the steering wheel of the electric vehicle 10 to return to the right, the steering wheel angle gradually decreases, and the electric vehicle 10 is in the later stage of turning left and moving forward. At this time, the controller 400 controls the left rear wheel RL to stop rotating. At the same time, the controller 400 controls the braking device of the electric vehicle 10 to gradually reduce the braking force F1 output to the left front wheel FL, so that the speed of the left front wheel FL is gradually increased, thereby reducing the speed difference between the left front wheel FL and the right front wheel FR to reduce the torque of the left yaw motion provided to the electric vehicle 10, so that the electric vehicle 10 gradually returns to the center.

[0096] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T42 after time T41, the braking force F1 output by the left front wheel FL is reduced to zero, the rotation speeds of the left front wheel FL and the right front wheel FR both reach the rotation speeds indicated by the accelerator pedal, and the electric vehicle 10 continues to move forward.

[0097] In one embodiment, at the fourth moment T4, in addition to controlling the drive motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate in the opposite direction, the drive motor corresponding to the right rear wheel RR can also be controlled to drive the right rear wheel RR to rotate forwardly, thereby increasing the torque of the electric vehicle's leftward yaw motion. In the specific implementation, the left rear wheel RL is controlled to rotate in the opposite direction while the right rear wheel RR is controlled to rotate forwardly; or, the left rear wheel RL is controlled to rotate in the opposite direction first, and then the right rear wheel RR is controlled to rotate forwardly; or, the right rear wheel RR is controlled to rotate forwardly first, and then the left rear wheel RL is controlled to rotate in the opposite direction.

[0098] It should be understood that when the electric vehicle 10 turns right and moves forward, the controller 400 can also control the two front wheels and the right rear wheel according to the above technical principles, and the embodiments of the present application will not be elaborated here.

[0099] When the electric vehicle 10 turns during the floating driving process, the body of the electric vehicle 10 tilts toward the turning side, resulting in an increase in the wading depth of the turning side, which is prone to safety problems. Therefore, it is necessary to adjust the body height of the electric vehicle 10 when turning during the floating driving process so that the electric vehicle 10 can maintain balance.

[0100] In one embodiment, when the electric vehicle 10 turns left and moves forward during the floating driving process, the controller 400 controls the suspension system 500 to raise the height of the left side of the electric vehicle from the second moment T2 to prevent the electric vehicle from excessively tilting the body, so as to help the electric vehicle maintain balance when turning. After the steering wheel of the electric vehicle 10 is returned to the center, the controller 400 controls the suspension system 500 to lower the height of the left side to the same height as the right side.

[0101] When the driver increases the stroke of the accelerator pedal during the floating driving of the electric vehicle 10, the electric vehicle 10 will accelerate. However, the body of the electric vehicle 10 tilts backward excessively when accelerating. At this time, the body height of the electric vehicle 10 also needs to be adjusted to keep the electric vehicle 10 balanced.

[0102] In one embodiment, when the driver increases the travel of the accelerator pedal during the floating driving of the electric vehicle 10 , the controller 400 controls the suspension system to raise the height of the rear vehicle body, so that the electric vehicle 10 maintains balance.

[0103] Based on the same technical principle, when the driver steps on the brake pedal or increases the travel of the brake pedal while the electric vehicle 10 is floating on water, the controller 400 controls the suspension system 500 to raise the front vehicle height to prevent the body of the electric vehicle 10 from tilting forward excessively, thereby keeping the electric vehicle 10 balanced.

[0104] When the electric vehicle 10 is traveling on water and there are waves on the wading section, the waves may impact the body of the electric vehicle 10 , causing the body of the electric vehicle 10 to shake.

[0105] In one embodiment, when the electric vehicle 10 is floating on water, the controller 400 can control the suspension system 500 to raise the height of the left vehicle body when waves are detected on the right side of the electric vehicle 10, so as to offset the impact of the waves on the electric vehicle 10 through the suspension system 500, thereby ensuring that the electric vehicle 10 travels more smoothly.

[0106] When waves are detected on other sides of the electric vehicle 10 , the controller 400 can also raise the vehicle height based on the same technical principle to offset the impact of the waves on the electric vehicle 10 .

[0107] In one embodiment, after the driver steps on the brake pedal to stop the electric vehicle 10 from moving forward and switches the gear of the electric vehicle 10 to the reverse gear after the time T42 during the floating driving process, the controller 400 can control the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate in the opposite direction according to the travel of the accelerator pedal, thereby driving the electric vehicle 10 to travel backward. Figure 8 The technical principles in the control of electric vehicles to turn faster.

[0108] Fig. 9 Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig. 9 As shown, the fifth moment T5 represents that the steering wheel turning leftward during the electric vehicle 10 floating on water is less than the first preset angle θ1. The sixth moment T6 represents that the steering wheel turning leftward increases to the first preset angle θ1 during the electric vehicle 10 backward.

[0109] At the fifth moment T5 when the electric vehicle 10 is traveling backwards on water, the steering wheel of the electric vehicle turns left at a less than the preset angle θ1, indicating that the electric vehicle 10 does not need to turn or only needs to fine-tune the driving direction. At this time, the controller 400 controls the corresponding drive motor in the drive system 100 to drive the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate in the opposite direction, which can drive the electric vehicle 10 to travel backwards. Among them, at the fifth moment T5, the speed n1 of the left front wheel FL is equal to the speed n2 of the right front wheel FR.

[0110] In one embodiment, Fig. 9 As shown, at the sixth moment T6 after the fifth moment T5, the driver increases the steering angle of the steering wheel to the left to the first preset angle θ1, indicating that the electric vehicle 10 needs to turn left. At this time, the left front wheel FL and the right front wheel FR will turn left with the turning of the steering wheel. In this scenario, the rotation speed n1 of the left front wheel FL is equal to the rotation speed n2 of the right front wheel FR, which cannot provide the electric vehicle 10 with a yaw motion torque, causing the electric vehicle 10 to turn slowly. At this time, the controller 400 automatically controls the braking device of the electric vehicle 10 to output the braking force F1 to brake the left front wheel FL of the electric vehicle 10, so that the rotation speed n1 of the left front wheel FL of the electric vehicle 10 is less than the rotation speed n2 of the right front wheel FR, which can provide the electric vehicle 10 with a yaw motion torque to the left, helping the electric vehicle 10 to turn left faster.

[0111] In one embodiment, the driver continues to turn the steering wheel to the left, and the steering angle of the steering wheel to the left increases to the second preset angle θ2, indicating that the electric vehicle 10 needs to turn at a larger steering angle. At this time, a larger torque for left yaw motion needs to be provided to the electric vehicle 10. Fig. 9 As shown, at the seventh moment T7 after the sixth moment T6, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged, and controls the braking device of the electric vehicle 10 to increase the braking force F1 on the left front wheel FL, thereby increasing the rotation speed difference between the left front wheel FL and the right front wheel FR, providing the electric vehicle 10 with a larger torque for left yaw motion, and helping the electric vehicle 10 to turn faster.

[0112] In one embodiment, Fig. 9As shown, at the eighth moment T8 after the seventh moment T7, the left turning angle of the steering wheel increases to the third preset angle θ3 (i.e., the maximum turning angle or close to the maximum turning angle of the steering wheel), and the controller 400 controls the rotation speed n2 of the right front wheel FR to remain unchanged and controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate forward, so as to reduce the power provided by the left wheel to the electric vehicle 10, so that the forward power provided by the right wheel of the electric vehicle 10 is greater than the power provided by the left wheel, thereby further increasing the torque provided for the electric vehicle 10 to move to the left, and helping the electric vehicle 10 to turn faster.

[0113] Among them, Fig. 9 As shown, when the steering wheel turns leftward, the controller 400 immediately controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate forward. Based on this, on the basis of providing the electric vehicle 10 with a torque for left yaw motion by the speed difference between the left front wheel FL and the right front wheel FR, the average speed of the left wheel can be quickly reduced by the positive rotation of the left rear wheel RL, thereby reducing the power provided by the left wheel to the electric vehicle 10, increasing the torque for left yaw motion provided to the electric vehicle 10, and helping the electric vehicle 10 to turn faster.

[0114] In one embodiment, the controller 400 controls the left rear wheel RL to rotate forward after the steering wheel turns leftward and increases to the third preset angle θ3 for a period of time. In the above manner, controlling the left rear wheel RL to rotate forward after the electric vehicle 10 has turned to a certain angle can make the left rear wheel RL rotate forward at a lower speed, so that the electric vehicle 10 can turn more smoothly.

[0115] In one embodiment, at time T81 after the eighth time T8, the driver operates the steering wheel of the electric vehicle 10 to return to the right, the steering wheel angle gradually decreases, and the electric vehicle 10 is in the late stage of turning left and reversing. At this time, the controller 400 controls the left rear wheel RL to stop rotating and controls the braking device of the electric vehicle 10 to gradually reduce the braking force F1 output to the left front wheel FL, so that the rotation speed of the left front wheel FL is gradually increased, thereby reducing the rotation speed difference between the left front wheel FL and the right front wheel FR to reduce the torque of the left yaw motion provided to the electric vehicle 10, so that the electric vehicle 10 gradually returns to the center.

[0116] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T82 after time T81, the braking force F1 output by the left front wheel FL is reduced to zero, the rotation speeds of the left front wheel FL and the right front wheel FR both reach the rotation speeds indicated by the accelerator pedal, and the electric vehicle 10 continues to move forward.

[0117] It should be understood that when the electric vehicle 10 turns right and reverses, the controller 400 can also control the two front wheels and the right rear wheel according to the above technical principles, and the embodiments of the present application will not be elaborated here.

[0118] Furthermore, when the electric vehicle 10 is traveling backwards on water, the controller 400 can also raise the height of the vehicle body on the side of the turning direction when the electric vehicle 10 turns to maintain the balance of the electric vehicle. When the electric vehicle 10 accelerates, decelerates, or encounters waves while traveling backwards, the height of the vehicle body can also be adjusted to maintain balance, which will not be described in detail in the embodiments of the present application.

[0119] Fig.10 Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig.10 As shown, in one embodiment, when the electric vehicle 10 includes a rear-wheel steering system 600, the electric vehicle 10 turns left during the forward driving process. When the steering wheel turns left at the second moment T2 after the first moment T1, the controller 400 automatically controls the braking device of the electric vehicle 10 to output a braking force F1 to brake the left front wheel FL of the electric vehicle 10. At the same time, the controller 400 drives the rear-wheel steering system 600 to control the rear wheels to turn right to the first preset rear wheel angle -θ4 and controls the drive motor of the right rear wheel RR to drive the right rear wheel RR to rotate forward. "-" is used to indicate that the steering direction of the steering wheel of the electric vehicle 10 is to turn right, not to turn left. Among them, the rotation speed n4 of the right rear wheel RR can be slightly greater than the rotation speed of the right front wheel n2.

[0120] Based on this, on the basis that the left front wheel FL and the right front wheel FR rotate forward to drive the electric vehicle to turn left, the rotation speed of the left front wheel FL is less than the rotation speed of the right front wheel FR, which can increase the torque of the front of the electric vehicle to yaw to the left. In addition, the right rear wheel RR turns right and rotates forward to increase the right power while providing a torque for the rear of the electric vehicle 10 to yaw to the right, so that the electric vehicle 10 can complete the turn faster.

[0121] It should be understood that in actual implementation, when the speed n4 of the right rear wheel RR is less than or equal to the speed of the right front wheel n2, it can also provide a torque for the rear end of the electric vehicle 10 to yaw to the right. Therefore, the magnitude relationship between the speed n4 of the right rear wheel RR and the speed n2 of the right front wheel can be set according to actual needs.

[0122] In one embodiment, Fig.10As shown, at the third moment T3 after the second moment T2, when the driver controls the steering wheel to turn left and the angle continues to increase to the second preset angle θ2 but has not reached the maximum angle, the controller 400 automatically controls the corresponding drive motor to control the speed n2 of the right front wheel FR and the speed n4 of the right rear wheel RR to remain unchanged, and controls the braking device of the electric vehicle 10 to increase the braking force F1 output to the left front wheel FL, thereby increasing the speed difference between the left front wheel FL and the right front wheel FR, and providing the electric vehicle 10 with a greater torque for yaw movement to the left. At the same time, the controller 400 controls the rear wheels of the electric vehicle 10 to turn right and increase to the second preset rear wheel angle -θ5 (i.e., the maximum angle for turning right), thereby increasing the torque for yaw movement to the right provided to the rear of the vehicle when the right rear wheel RR rotates forward, helping the electric vehicle 10 to complete the turn faster.

[0123] In one embodiment, Fig.10 As shown, at the fourth moment T4 after the third moment T3, the driver controls the steering wheel to turn left and the angle continues to increase to the third preset angle θ3 (i.e., the maximum angle of the steering wheel or close to the maximum angle), and the controller 400 controls the braking device of the electric vehicle 10 to output the maximum braking force to the left front wheel FL, and the speed of the left front wheel FL is reduced to zero, so that the speed difference between the left front wheel FL and the right front wheel FR reaches the maximum value. At this time, the controller 400 controls the drive motors corresponding to the right front wheel FR and the right rear wheel RR to control the speed n2 of the right front wheel FR and the speed n4 of the right rear wheel RR to remain unchanged, and controls the drive motor of the left rear wheel RL to control the left rear wheel RL to rotate forward.

[0124] In the embodiment of the present application, controlling the left rear wheel RL to rotate forward on the basis of the right rear wheel RR to rotate forward can not only further increase the power of the electric vehicle 10, but also increase the torque of the rear end of the vehicle to the right, so that the electric vehicle can complete the turn faster.

[0125] In one embodiment, Fig.10 As shown, the rotation speed n3 of the left rear wheel RL is less than the rotation speed n4 of the right rear wheel. Based on this, the torque of the electric vehicle 10 to yaw to the left can be further increased, helping the electric vehicle 10 to turn left faster.

[0126] In one embodiment, when the steering wheel turns leftward, the controller 400 immediately controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate forward. Based on this, the rear end of the electric vehicle 10 can be controlled to swing to the right more timely, thereby helping the electric vehicle to complete the turn faster.

[0127] In one embodiment, the controller 400 controls the left rear wheel RL to rotate forward after the steering wheel turns leftward and increases to the third preset angle θ3 for a period of time. Based on this, controlling the left rear wheel RL to rotate forward after the electric vehicle 10 rotates for a period of time can reduce the speed required by the left rear wheel RL, thereby controlling the steering of the electric vehicle 10 more smoothly.

[0128] In one embodiment, at time T41 after the fourth time T4, the driver operates the steering wheel of the electric vehicle 10 to return to the right, the steering wheel angle gradually decreases, and the electric vehicle 10 is in the later stage of turning left and moving forward. At this time, the controller 400 controls the left rear wheel RL and the right rear wheel RR to stop rotating and controls the rear wheels to return to the center. At the same time, the controller 400 controls the braking device of the electric vehicle 10 to gradually reduce the braking force F1 output to the left front wheel FL, so that the speed of the left front wheel FL is gradually increased, thereby reducing the speed difference between the left front wheel FL and the right front wheel FR to reduce the torque provided to the electric vehicle 10 for the left yaw motion, so that the electric vehicle 10 gradually returns to the center.

[0129] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T42 after time T41, the braking force F1 output by the left front wheel FL is reduced to zero, the rotation speeds of the left front wheel FL and the right front wheel FR both reach the rotation speeds indicated by the accelerator pedal, and the electric vehicle 10 continues to move forward.

[0130] Furthermore, when the electric vehicle 10 is traveling forward on water, the controller 400 can also raise the height of the vehicle body on the side of the turning direction when the electric vehicle 10 turns to maintain the balance of the electric vehicle. When the electric vehicle 10 accelerates, decelerates, or encounters waves during its forward travel, the height of the vehicle body can also be adjusted to maintain balance, which will not be described in detail in the embodiments of the present application.

[0131] In one embodiment, after the driver steps on the brake pedal to stop the electric vehicle 10 from moving forward and switches the gear of the electric vehicle 10 to the reverse gear after the time T42 during the floating driving process, the controller 400 can control the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate in the opposite direction according to the travel of the accelerator pedal, thereby driving the electric vehicle 10 to move backward. Fig.10 The technical principles in the control of electric vehicles to turn faster.

[0132] Fig.11 Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig.11As shown, in one embodiment, when the electric vehicle 10 includes a rear-wheel steering system 600 and the electric vehicle 10 is traveling backward, at the sixth moment T6 after the fifth moment T5, when the steering wheel turns left at an angle that increases to a first preset angle θ1, the controller 400 automatically controls the brake device of the electric vehicle 10 to output a braking force F1 to brake the left front wheel FL of the electric vehicle 10. At the same time, the controller 400 drives the rear-wheel steering system 600 to control the rear wheels to turn right to a preset rear wheel angle θ4 and controls the drive motor of the right rear wheel RR to drive the right rear wheel RR to rotate in the opposite direction. Among them, the rotation speed n4 of the right rear wheel RR can be slightly greater than the rotation speed of the right front wheel n2.

[0133] Based on this, on the basis that the left front wheel FL and the right front wheel FR rotate in opposite directions to drive the electric vehicle 10 to turn left and travel backward, the rotation speed of the left front wheel FL is lower than the rotation speed of the right front wheel FR, which can increase the torque of the front of the electric vehicle 10 to yaw to the left. In addition, the right rear wheel RR turns right and rotates in the opposite direction, which can increase the power of the electric vehicle 10 while providing a torque for the rear of the electric vehicle 10 to yaw to the left, so that the electric vehicle 10 can complete the turn faster.

[0134] It should be understood that in actual implementation, when the rotation speed n4 of the right rear wheel RR is less than or equal to the rotation speed of the right front wheel n2, it can also provide a torque for the rear end of the electric vehicle 10 to yaw to the left. Therefore, the magnitude relationship between the rotation speed n4 of the right rear wheel RR and the rotation speed of the right front wheel n2 can be set according to actual needs.

[0135] In one embodiment, Fig.11 As shown, at the seventh moment T7 after the sixth moment T6, when the driver controls the steering wheel to turn left gradually to the second preset angle θ2 but does not reach the maximum angle, the controller 400 automatically controls the corresponding drive motor to control the speed n2 of the right front wheel FR and the speed n4 of the right rear wheel RR to remain unchanged, and controls the braking device of the electric vehicle 10 to increase the braking force F1 output to the left front wheel FL, thereby increasing the speed difference between the left front wheel FL and the right front wheel FR, and providing the electric vehicle 10 with a greater torque for yaw movement to the left. At the same time, the controller 400 controls the rear wheels of the electric vehicle 10 to turn right to increase to the preset rear wheel angle θ5 (i.e., the maximum angle for turning right), thereby increasing the torque for yaw movement to the left provided to the rear of the vehicle when the right rear wheel RR rotates forward, helping the electric vehicle 10 to complete the turn faster.

[0136] In one embodiment, Fig.11As shown, at the eighth moment T8 after the seventh moment T7, the driver controls the steering wheel to turn left and the angle continues to increase to the third preset angle θ3 (i.e., the maximum angle of the steering wheel or close to the maximum angle), and the controller 400 controls the braking device of the electric vehicle 10 to output the maximum braking force to the left front wheel FL, and the speed of the left front wheel FL is reduced to zero, so that the speed difference between the left front wheel FL and the right front wheel FR reaches the maximum value. At this time, the controller 400 controls the drive motors corresponding to the right front wheel FR and the right rear wheel RR to control the speed n2 of the right front wheel FR and the speed n4 of the right rear wheel RR to remain unchanged, and controls the drive motor of the left rear wheel RL to control the left rear wheel RL to rotate in the opposite direction.

[0137] In the embodiment of the present application, controlling the reverse rotation of the left rear wheel RL based on the reverse rotation of the right rear wheel RR can not only further increase the power of the electric vehicle 10, but also increase the torque of the rear end of the vehicle to the left, so that the electric vehicle 10 can complete the turn faster.

[0138] In one embodiment, Fig.11 As shown, the rotation speed n3 of the left rear wheel RL is less than the rotation speed n4 of the right rear wheel. Based on this, the torque of the electric vehicle 10 to yaw to the left can be further increased, helping the electric vehicle 10 to turn left faster.

[0139] In one embodiment, the controller 400 immediately controls the left rear wheel RL to rotate in the opposite direction when the left turning angle of the steering wheel increases to the third preset turning angle θ3, thereby controlling the electric vehicle to increase the steering angle in a more timely manner.

[0140] In one embodiment, the controller 400 controls the left rear wheel RL to rotate in the opposite direction after the steering wheel turns leftward and increases to the third preset angle θ3 for a period of time. Based on this, controlling the left rear wheel RL to rotate in the opposite direction after the electric vehicle 10 rotates for a period of time can make the rotation speed of the left rear wheel RL lower, thereby controlling the steering of the electric vehicle 10 more smoothly.

[0141] In one embodiment, at time T81 after the eighth time T8, the driver operates the steering wheel of the electric vehicle 10 to return to the right, the steering wheel angle gradually decreases, and the electric vehicle 10 is in the late stage of turning left and driving backward. At this time, the controller 400 controls the left rear wheel RL and the right rear wheel RR to stop rotating and controls the rear wheels to return to the center. At the same time, the controller 400 controls the braking device of the electric vehicle 10 to gradually reduce the braking force F1 output to the left front wheel FL, so that the speed of the left front wheel FL is gradually increased, thereby reducing the speed difference between the left front wheel FL and the right front wheel FR to reduce the torque provided to the electric vehicle 10 for the left yaw motion, so that the electric vehicle 10 gradually returns to the center.

[0142] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T82 after time T81, the braking force F1 output by the left front wheel FL is reduced to zero, the rotation speeds of the left front wheel FL and the right front wheel FR both reach the rotation speeds indicated by the accelerator pedal, and the electric vehicle 10 continues to move backward.

[0143] Furthermore, when the electric vehicle 10 is traveling backwards on water, the controller 400 can also raise the height of the vehicle body on the side of the turning direction when the electric vehicle 10 turns to maintain the balance of the electric vehicle. When the electric vehicle 10 accelerates, decelerates, or encounters waves while traveling backwards, the height of the vehicle body can also be adjusted to maintain balance, which will not be described in detail in the embodiments of the present application.

[0144] Fig.12 Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig.12 As shown, the fifth moment T5 represents that the steering wheel turning angle to the left during the electric vehicle 10 moving backward is less than the fourth preset angle θ4, and the sixth moment T6 represents that the steering wheel turning angle to the left during the electric vehicle 10 moving backward increases to the fourth preset angle θ4.

[0145] In one embodiment, at the fifth moment T5 when the electric vehicle 10 is traveling backwards, the left turning angle of the steering wheel of the electric vehicle is less than the fourth preset turning angle θ4, indicating that the electric vehicle 10 does not need to turn or only needs to fine-tune the driving direction. At this time, the controller 400 controls the corresponding drive motor in the drive system 100 to drive the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate in the opposite direction, which can drive the electric vehicle 10 to travel backwards. Among them, at the fifth moment T5, the speed n1 of the left front wheel FL is equal to the speed n2 of the right front wheel FR.

[0146] In one embodiment, at the sixth moment T6 after the fifth moment T5, when the driver continues to turn the steering wheel to increase the steering wheel turning angle to the left to the fourth preset angle θ4, the controller 400 automatically controls the braking device of the left front wheel FL to output the braking force F1 to brake the left front wheel FL, so that the speed difference between the rotational speed n1 of the left front wheel FL and the rotational speed n2 of the right front wheel FR is the first speed difference, thereby providing the electric vehicle 10 with additional torque for left yaw motion, helping the electric vehicle 10 to turn left faster.

[0147] In one embodiment, at the seventh moment T7 after the sixth moment T6, when the driver continues to turn the steering wheel to the left so that the steering wheel turns leftward and the steering angle increases to the fifth preset angle θ5 but does not reach the maximum angle, the controller 400 automatically controls the speed n2 of the right front wheel FR to remain unchanged and controls the braking force F1 output by the braking device of the left front wheel FL to remain unchanged, so that the speed difference between the left front wheel FL and the right front wheel FR is still the first speed difference, thereby controlling the torque of the electric vehicle 10 to yaw to the left to remain unchanged, so that the electric vehicle 10 can turn smoothly. The left and right wheel speed difference increases stepwise with the increase of the steering wheel angle, which can reduce the frequency adjustment of the change of the left and right wheel speeds, which is conducive to further maintaining the stability of the vehicle body during steering.

[0148] In one embodiment, at the eighth moment T8 after the seventh moment T7, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the sixth preset turning angle θ6 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged and controls the brake transposition of the left front wheel FL to increase the output braking force F1, so that the rotation speed difference between the left front wheel FL and the right front wheel FR is the second rotation speed difference, thereby increasing the torque of the electric vehicle 10 to the left yaw motion, helping the electric vehicle 10 to turn faster.

[0149] In one embodiment, Fig.12 As shown, at the ninth moment T9 after the eighth moment T8, the left turning angle of the steering wheel increases to the seventh preset angle θ7 (i.e., the maximum turning angle or close to the maximum turning angle of the steering wheel), and the controller 400 controls the rotation speed n2 of the right front wheel FR and the braking force F1 of the left front wheel FL to remain unchanged and controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate forward, so as to reduce the power provided by the left wheel to the electric vehicle 10, so that the power provided by the right wheel of the electric vehicle 10 is greater than the power provided by the left wheel, thereby further increasing the torque provided for the electric vehicle 10 to move to the left, and helping the electric vehicle 10 to turn faster.

[0150] Among them, Fig.12 As shown, when the steering wheel turns leftward to the seventh preset angle θ7, the controller 400 immediately controls the drive motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate forward. Based on this, the power provided by the left wheel to the electric vehicle can be quickly reduced by the forward rotation of the left rear wheel RL, thereby increasing the torque provided to the electric vehicle 10 for the left yaw motion, and helping the electric vehicle 10 to turn faster.

[0151] In one embodiment, the controller 400 controls the left rear wheel RL to rotate forward after the steering wheel turns leftward and increases to the seventh preset angle θ7 for a period of time. Based on this, controlling the left rear wheel RL to rotate forward after the electric vehicle 10 has turned to a certain angle can make the left rear wheel RL rotate forward at a lower speed, thereby reducing the shaking of the electric vehicle 10 during floating driving.

[0152] In one embodiment, at time T91 after the ninth time T9, the driver operates the steering wheel of the electric vehicle 10 to return to the right, and the steering wheel angle gradually decreases. The electric vehicle 10 is in the later stage of driving backward during the left turn, and it is necessary to reduce the torque of the electric vehicle 10 yaw to the left so that the electric vehicle 10 can return to the center quickly. At this time, the controller 400 controls the left rear wheel RL to stop rotating. At the same time, the controller 400 controls the braking device of the electric vehicle 10 to reduce the braking force F1 output to the left front wheel FL to zero, so that the speed n1 of the left front wheel FL is equal to the speed n2 of the right front wheel, thereby reducing the torque of the left yaw movement provided to the electric vehicle 10 more quickly, so that the electric vehicle 10 can travel at a faster speed.

[0153] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T92 after time T91, the left front wheel FL and the right front wheel FR continue to drive the electric vehicle 10 backward at the same rotation speed.

[0154] In one embodiment, the controller 400 can control the driving motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate forward at the ninth moment T9, and can also control the driving motor corresponding to the right rear wheel RR to drive the right rear wheel RR to rotate reversely, thereby increasing the torque of the electric vehicle to yaw to the left. In the specific implementation, the left rear wheel RL is controlled to rotate forward while the right rear wheel RR is controlled to rotate reversely; or, the left rear wheel RL is controlled to rotate forward first, and then the right rear wheel RR is controlled to rotate reversely; or, the right rear wheel RR is controlled to rotate reversely first, and then the left rear wheel RL is controlled to rotate forward.

[0155] It should be understood that when the electric vehicle 10 is driving backward while turning right, the controller 400 can also control the two front wheels and the right rear wheel with reference to the above technical principles, and the embodiments of the present application will not be elaborated here.

[0156] When the electric vehicle 10 turns during the floating driving process, the body of the electric vehicle 10 tilts toward the turning side, resulting in an increase in the wading depth of the turning side, which is prone to safety problems. Therefore, it is necessary to adjust the body height of the electric vehicle 10 when turning during the floating driving process so that the electric vehicle 10 can maintain balance.

[0157] In one embodiment, when the electric vehicle 10 is turning left and driving backward, the controller 400 controls the suspension system 500 to raise the height of the left side of the electric vehicle from the sixth moment T6 to prevent the electric vehicle 10 from tilting to the left, so as to help the electric vehicle maintain balance when turning. After the steering wheel of the electric vehicle 10 is returned to the center, the controller 400 controls the suspension system 500 to lower the height of the left side of the electric vehicle to the same height as the right side of the electric vehicle.

[0158] When the driver increases the stroke of the accelerator pedal during the floating driving of the electric vehicle 10, the electric vehicle 10 will accelerate. However, the electric vehicle 10 over-tilts backward when accelerating. At this time, the height of the electric vehicle 10 also needs to be adjusted to keep the electric vehicle 10 balanced.

[0159] In one embodiment, when the driver increases the travel of the accelerator pedal during the floating driving of the electric vehicle 10 , the controller 400 controls the suspension system to raise the height of the rear vehicle body, so that the electric vehicle 10 maintains balance.

[0160] Based on the same technical principle, when the driver steps on the brake pedal or increases the travel of the brake pedal during the floating driving of the electric vehicle 10, the controller 400 controls the suspension system 500 to raise the front vehicle height to prevent the electric vehicle 10 from excessively tilting forward, thereby keeping the electric vehicle 10 balanced.

[0161] When the electric vehicle 10 is traveling on water and there are waves on the wading section, the waves may impact the body of the electric vehicle 10 , causing the body of the electric vehicle 10 to shake.

[0162] In one embodiment, when the electric vehicle 10 is floating on water, the controller 400 can control the suspension system 500 to raise the height of the left vehicle body when waves are detected on the right side of the electric vehicle 10, so as to offset the impact of the waves on the electric vehicle 10 through the suspension system 500, thereby ensuring that the electric vehicle 10 travels more smoothly.

[0163] When waves are detected on other sides of the electric vehicle 10 , the controller 400 can also raise the vehicle height based on the same technical principle to offset the impact of the waves on the electric vehicle 10 .

[0164] In one embodiment, after the driver steps on the brake pedal to control the electric vehicle 10 to stop moving backward and switches the gear of the electric vehicle 10 to the forward gear after the T92 moment during the floating driving process, the controller 400 can control the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate forward according to the travel of the accelerator pedal, thereby driving the electric vehicle 10 to move forward.

[0165] Fig.13Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig.13 As shown, the eleventh moment T11 represents that the steering wheel of the electric vehicle 10 turns leftward when the electric vehicle 10 is moving forward and the turning angle is less than the fourth preset turning angle θ4. The twelfth moment T12 represents that the steering wheel turns leftward when the electric vehicle 10 is moving forward and increases to the fourth preset turning angle θ4.

[0166] At the eleventh moment T11 when the electric vehicle 10 is moving forward, the angle of the steering wheel of the electric vehicle turning left is less than the fourth preset angle θ4, indicating that the electric vehicle 10 does not need to turn or only needs to fine-tune the driving direction. At this time, the controller 400 controls the corresponding drive motor in the drive system 100 to drive the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate forward, which can drive the electric vehicle 10 to move forward. Among them, at the first moment T1, the speed n1 of the left front wheel FL is equal to the speed n2 of the right front wheel FR.

[0167] In one embodiment, Fig.13 As shown, at the twelfth moment T12 after the eleventh moment T11, the driver increases the steering wheel turning angle to the left to the fourth preset angle θ4, indicating that the electric vehicle 10 needs to turn left, and the controller 400 controls the brake transposition output braking force F1 of the left front wheel FL to brake the left front wheel FL, so that the speed difference between the rotational speed n1 of the left front wheel FL and the rotational speed n2 of the right front wheel FR is the first speed difference, thereby providing the electric vehicle 10 with additional torque for left yaw motion, helping the electric vehicle 10 to turn left faster.

[0168] In one embodiment, at the thirteenth moment T13 after the twelfth moment T12, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the fifth preset turning angle θ5 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged and controls the braking force F1 output by the braking device of the left front wheel FL to remain unchanged, so that the rotation speed difference between the left front wheel FL and the right front wheel FR remains the first rotation speed difference, thereby controlling the torque of the electric vehicle 10 to yaw to the left to remain unchanged, so that the electric vehicle 10 can turn smoothly.

[0169] In one embodiment, at the fourteenth moment T14 after the thirteenth moment T13, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the sixth preset turning angle θ6 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged and controls the brake transposition of the left front wheel FL to increase the output braking force F1, so that the rotation speed difference between the left front wheel FL and the right front wheel FR is the second rotation speed difference, thereby increasing the torque of the electric vehicle 10 to the left yaw motion, helping the electric vehicle 10 to turn faster.

[0170] In one embodiment, Fig.13 As shown, at the fifteenth moment T15 after the fourteenth moment T14, the left turning angle of the steering wheel increases to the seventh preset angle θ7 (i.e., the maximum turning angle or close to the maximum turning angle of the steering wheel), the controller 400 controls the rotation speed n2 of the right front wheel FR and the braking force F1 of the left front wheel FL to remain unchanged and controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate in the opposite direction, so as to reduce the power provided by the left wheel to the electric vehicle 10, so that the power provided by the right wheel of the electric vehicle 10 is greater than the power provided by the left wheel, thereby further increasing the torque provided for the electric vehicle 10 to move to the left, and helping the electric vehicle 10 to turn faster.

[0171] Among them, Fig.13 As shown, when the steering wheel turns leftward at a seventh preset angle θ7, the controller 400 immediately controls the drive motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate in the opposite direction. Based on this, the power provided by the left wheel to the electric vehicle can be quickly reduced by the reverse rotation of the left rear wheel RL, thereby increasing the torque provided to the electric vehicle 10 for the left yaw motion, and helping the electric vehicle 10 to turn faster.

[0172] In one embodiment, the controller 400 controls the left rear wheel RL to rotate in the opposite direction after the steering wheel turns leftward and increases to the seventh preset angle θ7 for a period of time. Based on this, controlling the left rear wheel RL to rotate forward after the electric vehicle 10 has turned to a certain angle can make the left rear wheel RL rotate in the opposite direction at a lower speed, thereby reducing the shaking of the electric vehicle 10 during floating driving.

[0173] In one embodiment, at time T16 after the fifteenth time T15, the driver operates the steering wheel of the electric vehicle 10 to return to the right, the steering wheel angle gradually decreases, and the electric vehicle 10 is in the late stage of driving forward in the process of turning left. At this time, the controller 400 controls the left rear wheel RL to stop rotating. At the same time, the controller 400 controls the braking force F1 output by the braking device of the electric vehicle 10 to the left front wheel FL to zero, so that the speed n1 of the left front wheel FL is controlled to be equal to the speed n2 of the right front wheel FR, thereby reducing the torque of the left yaw motion provided to the electric vehicle 10 more quickly, so that the electric vehicle 10 can travel at a faster speed.

[0174] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T17 after time T16, the left front wheel FL and the right front wheel FR continue to drive the electric vehicle 10 forward at the same rotation speed.

[0175] In one embodiment, the controller 400 can control the drive motor corresponding to the left rear wheel RL to drive the left rear wheel RL to rotate in the opposite direction at the fifteenth moment T15, and can also control the drive motor corresponding to the right rear wheel RR to drive the right rear wheel RR to rotate forward, thereby increasing the torque of the electric vehicle to yaw to the left. In the specific implementation, the left rear wheel RL is controlled to rotate in the opposite direction while the right rear wheel RR is controlled to rotate forward; or, the left rear wheel RL is controlled to rotate in the opposite direction first, and then the right rear wheel RR is controlled to rotate forward; or, the right rear wheel RR is controlled to rotate forward first, and then the left rear wheel RL is controlled to rotate in the opposite direction.

[0176] It should be understood that when the electric vehicle 10 is moving forward while turning right, the controller 400 can also control the two front wheels and the right rear wheel with reference to the above technical principles, and the embodiments of the present application will not be elaborated here.

[0177] Furthermore, when the electric vehicle 10 is traveling forward on water, the controller 400 can also raise the height of the vehicle body on the side of the turning direction when the electric vehicle 10 turns to maintain the balance of the electric vehicle. When the electric vehicle 10 is accelerating, decelerating, or encountering waves while traveling backward, the height of the vehicle body can also be adjusted to maintain balance, which will not be described in detail in the embodiments of the present application.

[0178] Fig.14 Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig.14 As shown, in one embodiment, when the electric vehicle 10 includes a rear-wheel steering system 600, at the sixth moment T6 after the fifth moment T5, when the driver continues to turn the steering wheel to increase the steering angle of the steering wheel to the left to the fourth preset angle θ4, the controller 400 automatically controls the braking device of the left front wheel FL to output a braking force F1 to brake the left front wheel FL, so that the speed difference between the rotation speed n1 of the left front wheel FL and the rotation speed n2 of the right front wheel FR is the first speed difference, thereby providing the electric vehicle 10 with a torque for yaw movement to the left. At the same time, the controller 400 controls the rear-wheel steering system 600 to control the rear wheels of the electric vehicle 10 to turn right to the third preset rear wheel angle -θ8 and controls the right rear wheel RR to rotate in the opposite direction at a speed n4, further increasing the torque for yaw movement to the left, so that the electric vehicle 10 turns left faster.

[0179] In one embodiment, the rotation speed n4 of the right rear wheel RR is greater than the rotation speed n2 of the right front wheel FR, so that the rear end of the electric vehicle 10 can turn faster when traveling backward.

[0180] In one embodiment, at the seventh moment T7 after the sixth moment T6, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the fifth preset turning angle θ5 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR, the braking force F1 output by the braking device of the left front wheel FL, and the rotation speed n4 of the right rear wheel RR to remain unchanged, thereby controlling the torque of the electric vehicle 10 to yaw to the left to remain unchanged, so that the electric vehicle 10 can turn smoothly.

[0181] In one embodiment, at the eighth moment T8 after the seventh moment T7, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the sixth preset turning angle θ6 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR and the rotation speed n4 of the right rear wheel to remain unchanged and controls the brake transposition of the left front wheel FL to increase the output braking force F1, so that the rotation speed difference between the left front wheel FL and the right front wheel FR is the second rotation speed difference, thereby increasing the torque of the electric vehicle 10 to the left yaw motion, helping the electric vehicle 10 to turn faster.

[0182] In one embodiment, Fig.14 As shown, at the ninth moment T9 after the eighth moment T8, the left turning angle of the steering wheel increases to the seventh preset angle θ7 (i.e., the maximum turning angle or close to the maximum turning angle of the steering wheel), and the controller 400 controls the rotation speed n2 of the right front wheel FR, the rotation speed n4 of the right rear wheel RR and the braking force F1 of the left front wheel FL to remain unchanged, and controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate in the opposite direction at a rotation speed n3, thereby increasing the steering power of the electric vehicle 10 and the torque of the electric vehicle 10 to yaw to the left, helping the electric vehicle 10 to turn faster.

[0183] In one embodiment, when the turning angle of the rear-wheel steering system 600 reaches the maximum at the ninth moment T9, the controller 400 can also increase the turning angle of the rear wheels to increase the torque of the electric vehicle 10 to yaw to the left, helping the electric vehicle 10 to turn faster.

[0184] In one embodiment, the rotation speed n3 of the left rear wheel RL is less than the rotation speed n4 of the right rear wheel RR. Based on this, the torque of the electric vehicle 10 to yaw to the left can be further increased.

[0185] In one embodiment, at time T91 after the ninth time T9, the driver operates the steering wheel of the electric vehicle 10 to return to the right, and the steering wheel angle gradually decreases. The electric vehicle 10 is in the later stage of driving backward during the left turn, and it is necessary to reduce the torque of the electric vehicle 10 to the left so that the electric vehicle 10 can quickly return to the center. At this time, the controller 400 controls the wheel speed n3 of the left rear wheel RL and the wheel speed n4 of the right rear wheel RR to be reduced to zero. At the same time, the controller 400 controls the braking force F1 output by the braking device of the electric vehicle 10 to the left front wheel FL to zero, so that the rotation speed n1 of the left front wheel FL is equal to the rotation speed n2 of the right front wheel, thereby reducing the torque of the left yaw movement provided to the electric vehicle 10 more quickly, so that the electric vehicle 10 can travel at a faster speed.

[0186] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T92 after time T91, the left front wheel FL and the right front wheel FR continue to drive the electric vehicle 10 backward at the same rotation speed.

[0187] It should be understood that when the electric vehicle 10 is driving backward while turning right, the controller 400 can also control the electric vehicle 10 to turn faster by referring to the above technical principles, and the embodiments of the present application will not be elaborated here.

[0188] Furthermore, during the process of increasing the steering wheel angle, the control strategies in the above-mentioned various embodiments can also be executed simultaneously at the same time according to actual needs to maximize the steering efficiency of the electric vehicle 10.

[0189] In one embodiment, after the driver steps on the brake pedal to stop the electric vehicle 10 from moving backward and switches the gear of the electric vehicle 10 to the forward gear after T92 during the floating driving process, the controller 400 can control the left front wheel FL and the right front wheel FR of the electric vehicle 10 to rotate forward according to the travel of the accelerator pedal, thereby driving the electric vehicle 10 to move forward. Fig.14 The technical principle in controls the electric vehicle 10 to turn faster.

[0190] Fig.15 Another schematic diagram of the floating driving steering control method provided in the embodiment of the present application. Fig.15As shown, in one embodiment, when the electric vehicle 10 includes a rear-wheel steering system and is traveling forward, at the twelfth moment T12 after the eleventh moment T11, the driver increases the steering angle of the steering wheel to the left to the fourth preset angle θ4, indicating that the electric vehicle 10 needs to turn left and travel, and the controller 400 controls the brake transposition of the left front wheel FL to output the braking force F1 to brake the left front wheel FL, so that the speed difference between the rotation speed n1 of the left front wheel FL and the rotation speed n2 of the right front wheel FR is the first speed difference, thereby providing the electric vehicle 10 with a left yaw moment. At the same time, the controller 400 controls the rear-wheel steering system 600 to control the rear wheels of the electric vehicle 10 to turn right to the third preset rear wheel angle -θ8 and controls the right rear wheel RR to rotate forward, further increasing the torque of the left yaw motion, so that the electric vehicle 10 turns left faster.

[0191] In one embodiment, at the thirteenth moment T13 after the twelfth moment T12, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the fifth preset turning angle θ5 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged and controls the braking force F1 output by the braking device of the left front wheel FL to remain unchanged, so that the rotation speed difference between the left front wheel FL and the right front wheel FR remains the first rotation speed difference, thereby controlling the torque of the electric vehicle 10 to yaw to the left to remain unchanged, so that the electric vehicle 10 can turn smoothly.

[0192] In one embodiment, at the fourteenth moment T14 after the thirteenth moment T13, when the driver continues to turn the steering wheel to the left so that the steering wheel turning angle to the left increases to the sixth preset turning angle θ6 but does not reach the maximum turning angle, the controller 400 automatically controls the rotation speed n2 of the right front wheel FR to remain unchanged and controls the brake transposition of the left front wheel FL to increase the output braking force F1, so that the rotation speed difference between the left front wheel FL and the right front wheel FR is the second rotation speed difference, thereby increasing the torque of the electric vehicle 10 to the left yaw motion, helping the electric vehicle 10 to turn faster.

[0193] In one embodiment, Fig.15 As shown, at the fifteenth moment T15 after the fourteenth moment T14, the left turning angle of the steering wheel increases to the seventh preset angle θ7 (i.e., the maximum turning angle or close to the maximum turning angle of the steering wheel), the controller 400 controls the rotation speed n2 of the right front wheel FR, the rotation speed n4 of the right rear wheel RR and the braking force F1 of the left front wheel FL to remain unchanged, and controls the drive motor corresponding to the left rear wheel RL in the drive system 100 to drive the left rear wheel RL to rotate forward, thereby increasing the steering power of the electric vehicle 10 and the torque of the electric vehicle 10 to yaw to the left, helping the electric vehicle 10 to turn faster.

[0194] In one embodiment, at time T16 after the fifteenth time T15, the driver operates the steering wheel of the electric vehicle 10 to return to the right, and the steering wheel angle gradually decreases. The electric vehicle 10 is in the later stage of driving backward during the left turn, and it is necessary to reduce the torque of the electric vehicle 10 to the left so that the electric vehicle 10 can quickly return to the center. At this time, the controller 400 controls the wheel speed n3 of the left rear wheel RL and the wheel speed n4 of the right rear wheel RR to be reduced to zero. At the same time, the controller 400 controls the braking device of the electric vehicle 10 to reduce the braking force F1 output by the left front wheel FL to zero, so that the rotation speed n1 of the left front wheel FL is equal to the rotation speed n2 of the right front wheel, thereby reducing the torque of the left yaw movement provided to the electric vehicle 10 more quickly, so that the electric vehicle 10 can travel at a faster speed.

[0195] In one implementation, after the steering wheel of the electric vehicle 10 is returned to the center position at time T17 after time T16, the left front wheel FL and the right front wheel FR continue to drive the electric vehicle 10 backward at the same rotation speed.

[0196] It should be understood that when the electric vehicle 10 is moving forward while turning right, the controller 400 can also control the electric vehicle 10 to turn faster by referring to the above technical principles, and the embodiments of the present application will not be elaborated here.

[0197] Furthermore, during the process of increasing the steering wheel angle, the control strategies in the above-mentioned various embodiments can also be executed simultaneously at the same time according to actual needs to maximize the steering efficiency of the electric vehicle 10.

[0198] In summary, the embodiments of the present application provide a steering control method for floating driving of an electric vehicle and an electric vehicle, which are applied to the technical field of electric vehicles, so as to provide the electric vehicle with a yaw motion torque by controlling the speed difference of the wheels on both sides when turning during the floating driving of the electric vehicle, thereby improving the steering efficiency of the electric vehicle during the floating driving process and reducing the design cost.

[0199] In several embodiments provided in the present application, each functional module may be integrated into one device, or each module may exist physically separately, or two or more modules may be integrated into one device.

[0200] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A method for controlling the steering of an electric vehicle while floating on water, characterized in that: The floating water driving steering control method is used to control the driving direction of the electric vehicle during floating water driving, and the floating water driving steering control method includes: At a first moment when the electric vehicle is moving forward, the steering wheel of the electric vehicle is turned leftward at an angle less than a first preset angle, driving the two front wheels of the electric vehicle to rotate forward; At a second moment after the first moment, the left turning angle of the steering wheel increases to the first preset turning angle, and the rotation speed of the left front wheel of the electric vehicle is controlled to be lower than the rotation speed of the right front wheel of the electric vehicle.

2. The floating driving steering control method according to claim 1, characterized in that: The floating driving steering control method further comprises: At a third moment after the second moment, the leftward turning angle of the steering wheel increases to a second preset turning angle, increasing the rotation speed difference between the left front wheel of the electric vehicle and the right front wheel of the electric vehicle.

3. The floating driving steering control method according to claim 2, characterized in that: The floating driving steering control method further comprises: After the second moment, controlling the braking device of the electric vehicle to brake the left front wheel of the electric vehicle; After the third moment, the braking device of the electric vehicle is controlled to increase the braking force on the left front wheel of the electric vehicle.

4. The floating driving steering control method according to claim 2 or 3, characterized in that: The floating driving steering control method further comprises: At a fourth moment after the third moment, the left turning angle of the steering wheel increases to a third preset turning angle, and the left rear wheel of the electric vehicle is controlled to rotate in the opposite direction.

5. The floating driving steering control method according to claim 1 or 2, characterized in that: The floating driving steering control method further comprises: At the second moment, the rear wheels of the electric vehicle are controlled to turn right to a first preset rear wheel turning angle and the right rear wheel is controlled to rotate in a positive direction.

6. The method for controlling the steering of a floating vehicle according to claim 5, characterized in that: The floating driving steering control method further comprises: At a third moment after the second moment, the rightward turning angle of the rear wheels of the electric vehicle is controlled to increase to a second preset rear wheel turning angle.

7. The method for controlling the steering of a floating vehicle according to claim 6, characterized in that: The floating driving steering control method further includes: at a fourth moment after the third moment, the left turning angle of the steering wheel increases to a third preset turning angle, and the left rear wheel of the electric vehicle is controlled to rotate forward.

8. A method for controlling steering of an electric vehicle while floating on water, characterized in that: The floating water driving steering control method is used to control the driving direction of the electric vehicle during floating water driving, and the floating water driving steering control method includes: At a fifth moment when the electric vehicle is traveling backward, the steering wheel of the electric vehicle is turned leftward at an angle less than a fourth preset angle, so that the two front wheels of the electric vehicle are driven to rotate in the opposite direction; At a sixth moment after the fifth moment, the left turning angle of the steering wheel increases to the fourth preset turning angle, and the speed difference between the right front wheel of the electric vehicle and the left front wheel of the electric vehicle is controlled to be the first speed difference.

9. The floating driving steering control method according to claim 8, characterized in that: The floating driving steering control method further comprises: At a seventh moment after the sixth moment, the left turning angle of the steering wheel increases to a fifth preset turning angle, and the speed difference between the right front wheel of the electric vehicle and the left front wheel of the electric vehicle is controlled to be a first speed difference; At the eighth moment after the seventh moment, the left turning angle of the steering wheel increases to the sixth preset angle, and the speed difference between the right front wheel of the electric vehicle and the left front wheel of the electric vehicle is controlled to be the second speed difference, and the second speed difference is greater than the first speed difference.

10. The floating driving steering control method according to claim 9, characterized in that: The floating driving steering control method further comprises: After the sixth moment, controlling the braking device of the electric vehicle to brake the left front wheel of the electric vehicle; After the eighth moment, the braking device of the electric vehicle is controlled to increase the braking force on the left front wheel of the electric vehicle.

11. The method for controlling the steering of a floating vehicle according to claim 10, characterized in that: The floating driving steering control method further comprises: At a ninth moment after the eighth moment, the left turning angle of the steering wheel reaches a seventh preset turning angle, and the left rear wheel of the electric vehicle is controlled to rotate forward.

12. The floating driving steering control method according to claim 9 or 10, characterized in that: The floating driving steering control method further comprises: At the sixth moment, the rear wheels of the electric vehicle are controlled to turn right to a third preset rear wheel turning angle and the right rear wheel is controlled to rotate in the opposite direction.

13. The method for controlling the steering of a floating vehicle according to claim 12, characterized in that: The floating driving steering control method further comprises: At a ninth moment after the eighth moment, the rear wheels of the electric vehicle are controlled to rotate in the reverse direction.

14. The method for controlling the steering of a floating vehicle according to any one of claims 8 to 13, characterized in that: The floating driving steering control method further comprises: At the sixth moment, the electric vehicle is controlled to raise the left side vehicle body height.

15. An electric vehicle, characterized in that: The electric vehicle uses the floating running steering control method according to any one of claims 1 to 14 to achieve floating running steering.

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