Safety performance testing and evaluating method for regenerative braking system of electric vehicle

Abstract

The invention discloses a safety performance test and evaluation method for a regenerative braking system of an electric vehicle, which comprises the following steps: firstly, selecting a test road and a road adhesion coefficient according to test requirements, and setting a test environment, an initial braking speed, a braking position and a vehicle state; and a corresponding braking mode can be selected according to a regenerative braking system carried by the tested vehicle. Then, the test vehicle can be placed on the test road with the selected road adhesion coefficient, the test vehicle is started to run along the test road, and when the test vehicle runs to the braking position and the vehicle speed reaches the set braking initial speed, the regenerative braking system is started, and the test vehicle is controlled to brake according to the set braking mode. And finally, detecting various test data in the braking process of the regenerative braking system in real time through various test devices arranged on the test vehicle, and evaluating the influence on the safety performance of the vehicle in the braking process of the regenerative braking system of the electric vehicle through the test data.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle regenerative braking system performance testing, and in particular to a safety performance testing and evaluation method for a regenerative braking system of an electric vehicle. Background Art

[0002] When braking, coasting, decelerating, or driving downhill, traditional vehicles convert kinetic and potential energy generated during driving into heat, accelerating wear on the braking system. Electric vehicle regenerative braking systems convert or partially convert kinetic and potential energy generated during braking, coasting, decelerating, or driving downhill into energy stored in an onboard rechargeable energy storage system, thereby achieving energy conservation and carbon reduction. However, to achieve extreme energy savings, some vehicles maximize regenerative braking energy recovery, resulting in excessive regenerative braking intensity. This compromises safety features such as anti-lock braking performance and cornering stability when the regenerative braking system is in operation. Existing testing methods only consider basic vehicle braking performance, anti-lock braking performance, and cornering stability under mechanical braking. They fail to consider safety features such as anti-lock braking performance and cornering stability when the regenerative braking system is engaged. Summary of the Invention

[0003] In response to the shortcomings of the existing technology, the present invention proposes a safety performance test and evaluation method for the regenerative braking system of an electric vehicle, which can test the impact of the regenerative braking system's participation in braking on the vehicle's safety performance. The specific technical solution is as follows: A safety performance test and evaluation method for a regenerative braking system of an electric vehicle is provided. In a first achievable manner, the method includes: Select a test road with the corresponding road adhesion coefficient according to the test requirements, and set the test environment, initial braking speed, braking position, as well as the vehicle status and braking method of the test vehicle; Driving the test vehicle along a test road, and when the test vehicle reaches a braking position, braking the test vehicle according to a set initial braking speed and braking mode; Various test data of the test vehicle during the braking process are detected in real time, and the safety performance of the regenerative braking system is evaluated based on the various test data.

[0004] In combination with the first possible implementation, in a second possible implementation, the braking mode is set according to the type of the regenerative braking system installed in the test vehicle.

[0005] In combination with the first feasible method, in the third feasible method, the braking position includes: the position where the speed of the test vehicle on the low adhesion coefficient road surface reaches the initial braking speed, the position where the wheel enters the low adhesion coefficient road surface from the high adhesion coefficient road surface, and the position where the left and right wheels enter two roads with different adhesion coefficients and / or a flat circular arc lane.

[0006] In combination with the first possible implementation, the fourth possible implementation further includes: adjusting the set driving speed of the test vehicle to continue the test to evaluate the safety performance of the regenerative braking system at different driving speeds.

[0007] In combination with the first possible implementation, a fifth possible implementation further includes: adjusting the vehicle state of the test vehicle to continue the test to evaluate the safety performance of the regenerative braking system under different vehicle states.

[0008] In combination with the first possible implementation, a sixth possible implementation further includes: adjusting the test environment to continue the test to evaluate the safety performance of the regenerative braking system under different test environments.

[0009] In combination with the first possible implementation, a seventh possible implementation further includes: adjusting the braking intensity of the regenerative braking system to continue testing to evaluate the safety performance of the regenerative braking system under different braking intensities.

[0010] In combination with the first possible implementation, in an eighth possible implementation, the safety performance of the regenerative braking system is evaluated based on various test data, including: The wheel slip ratio is calculated based on the acquired test data, and the safety performance of the regenerative braking system is evaluated by the wheel slip ratio.

[0011] Beneficial effect: The safety performance test and evaluation method of the electric vehicle regenerative braking system of the present invention can select a test road, set various test parameters and braking methods according to the test requirements and the type of regenerative braking system carried by the test vehicle, control the test vehicle to travel on the selected test road, control the vehicle to brake according to the selected braking method at the corresponding braking position, and detect various test data of the test vehicle in real time during the braking process. The safety performance of the regenerative braking system is evaluated through the test data, thereby realizing the test of the impact of the regenerative braking system participating in braking on the vehicle safety performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific embodiments of the present invention, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0013] Figure 1 This is a flow chart of a safety performance testing and evaluation method for an electric vehicle regenerative braking system provided by one embodiment of the present invention. DETAILED DESCRIPTION

[0014] The following embodiments of the technical solution of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only examples and are not intended to limit the scope of protection of the present invention.

[0015] like Figure 1 The flowchart of the safety performance test and evaluation method of the electric vehicle regenerative braking system shown in FIG. 1 includes: Step 1: Select a test road with the corresponding road adhesion coefficient according to the test requirements, and set the test environment, initial braking speed, braking position, and the vehicle state and braking method of the test vehicle; Step 2: driving the test vehicle along a test road. When the test vehicle reaches a braking position, the test vehicle brakes according to a set initial braking speed and braking mode. Step 3: Detect various test data of the test vehicle during the braking process in real time, and evaluate the safety performance of the regenerative braking system based on the various test data.

[0016] Specifically, first, a test road with a corresponding road adhesion coefficient can be selected based on the test requirements. The test environment, initial braking velocity, braking position, and vehicle status can be set. A braking method can also be selected based on the regenerative braking system installed on the test vehicle. Then, the test vehicle can be placed on the selected test road and driven along the test road. When the test vehicle reaches the braking position and its speed reaches the set initial braking velocity, the regenerative braking system is activated and the test vehicle is controlled to brake according to the set braking method. Finally, various test equipment installed on the test vehicle can be used to monitor various test data during the regenerative braking process in real time, such as wheel speed, vehicle speed, position, braking distance, braking deceleration, and steering wheel angle. The vehicle slip rate can be calculated from the wheel speed and vehicle speed to determine whether the regenerative braking system's braking will cause wheel lock. The position can be used to determine whether the regenerative braking system's braking will cause the vehicle to deviate from its driving path.

[0017] In this embodiment, the wheel slip ratio is optionally calculated based on the acquired test data, and the safety performance of the regenerative braking system is evaluated by the wheel slip ratio. The specific calculation formula of the wheel slip ratio is as follows: ; in, is the vehicle speed, is the wheel speed.

[0018] In this embodiment, optionally, the braking mode is set according to the type of the regenerative braking system installed in the test vehicle.

[0019] Specifically, regenerative braking systems include Type A, Type B, and Type A+B. Type A is a non-service braking system, where the electric regenerative braking function operates independently of the traditional service braking system and kinetic energy recovery is triggered by releasing the accelerator pedal. Type B is a component of the service braking system, deeply integrated with the mechanical braking system, and kinetic energy recovery is activated by depressing the brake pedal, consistent with traditional braking operation.

[0020] Due to the differences between Type A and Type B regenerative braking systems, the corresponding braking methods must be used during testing. If the regenerative braking system is Type A, regenerative braking is performed directly at the system's maximum braking intensity until the test vehicle's speed drops to the set speed threshold.

[0021] Specifically, on a straight asphalt or cement road with a low adhesion coefficient, an empty or fully loaded vehicle is accelerated to the set driving speed, and the braking intensity of the Type A electric regenerative braking system is set to maximum for regenerative braking, that is, only the Type A electric regenerative braking system is working, and service braking, emergency braking or parking braking should not be performed until the regenerative braking is engaged or the vehicle speed is less than 5km / h.

[0022] If the regenerative braking system is a Type B regenerative braking system, service braking is performed at various brake pedal openings until the test vehicle's speed drops to a set speed threshold. Specifically, on a straight, low-adhesion asphalt or concrete surface, an unladen or fully loaded vehicle is accelerated to a set speed. The regenerative braking system's braking intensity is then set to maximum, and service braking is performed at brake pedal openings of 15%, 30%, and 45%, respectively. Brake pedal opening is the percentage of current brake pedal travel to maximum brake pedal travel. For example, full braking is performed at 100% brake pedal opening until regenerative braking engages or the vehicle speed drops below 5 km / h.

[0023] When testing a Type B regenerative braking system, tests under different brake pedal opening conditions can be introduced, such as the brake pedal opening after the end of the brake pedal free travel (no braking force within this range), the opening to the opening where the braking intensity of the regenerative braking system gradually increases, the opening to the opening where regenerative braking is combined with mechanical braking, the opening to the opening where the mechanical braking intensity gradually increases, and finally the brake pedal opening (100%) where the brake pedal is fully depressed. This is to analyze the impact of driving habits on the braking safety performance of the vehicle's regenerative braking system.

[0024] If the regenerative braking system is an A+B type regenerative braking system, the regenerative braking system is adjusted to maximum braking intensity, and service braking is performed at different brake pedal openings until the test vehicle's speed drops to the set speed threshold. Specifically, the braking intensity of the Type A electric regenerative braking system is adjusted to maximum, and service braking is performed at brake pedal openings of 15%, 30%, and 45% until the vehicle's speed drops to 5 km / h.

[0025] In this embodiment, the braking position includes: the position where the speed of the test vehicle on the low adhesion coefficient road surface reaches the initial braking speed, the position where the wheel enters the low adhesion coefficient road surface from the high adhesion coefficient road surface, and the position where the left and right wheels enter two road surfaces with different adhesion coefficients, and / or a flat arc lane.

[0026] Specifically, during testing, a test road with a corresponding road adhesion coefficient can be selected based on the test requirements, and the braking position can be set. For example, during a general test, when the test vehicle's speed reaches the set initial braking speed, the regenerative braking system can be activated for testing. The braking position is the position where the vehicle speed reaches the initial braking speed.

[0027] When conducting a docking test, the test road needs to be set up with two road surfaces with different adhesion coefficients in sequence along the vehicle's driving direction, and the adhesion coefficient of the front road surface must be greater than the adhesion coefficient of the rear road surface, and k H ≥0.5 and k H / k L ≥2, k H is the high adhesion coefficient road adhesion coefficient, k L The braking position is at the junction of the front and rear roads, that is, the position where the wheel passes from the high-adhesion road surface to the low-adhesion road surface.

[0028] During the split-road test, a test section is set up along the vehicle's travel direction, with two surfaces with different adhesion coefficients placed side by side. The braking position is set at the starting point of the test section. When the vehicle reaches the starting point of the test section at the set initial braking speed, with the left and right wheels on the two surfaces with different adhesion coefficients, the regenerative braking system is activated for testing.

[0029] During the curve braking test, a flat circular lane is set up along the test road in the direction of vehicle travel. The braking position is the starting point of the flat circular lane. When the vehicle enters the flat circular lane at the set initial braking speed, the regenerative braking system is activated for testing.

[0030] In this embodiment, optionally, the method further includes: adjusting the set driving speed of the test vehicle to continue the test, so as to evaluate the safety performance of the regenerative braking system at different driving speeds.

[0031] After obtaining the braking safety performance of the regenerative braking system at the currently set initial braking speed, the braking intensity of the regenerative braking system of the test vehicle can also be adjusted, and the test can continue according to the above test steps to obtain the braking safety performance of the regenerative braking system at different initial braking speeds, so as to analyze the impact of the initial braking speed on the braking safety performance of the regenerative braking system and ensure the comprehensiveness of the test results.

[0032] In this embodiment, optionally, the method further includes adjusting the vehicle state of the test vehicle to continue the test, so as to evaluate the safety performance of the regenerative braking system under different vehicle states.

[0033] Specifically, after obtaining the braking safety performance of the regenerative braking system at the currently set initial braking speed, the vehicle state of the test vehicle can be adjusted to continue testing according to the above test steps, so as to obtain the braking safety performance of the regenerative braking system under different vehicle states, so as to analyze the impact of the vehicle state on the braking safety performance of the regenerative braking system and ensure the comprehensiveness of the test results.

[0034] In this embodiment, adjusting the vehicle state may include adjusting the vehicle load to obtain the braking safety performance of the regenerative braking system under different load conditions, such as no load and full load, and analyzing the impact of the load conditions on the braking safety performance of the regenerative braking system to ensure comprehensive test results. Adjusting the vehicle's state of charge (SOC) may also include obtaining the braking safety performance of the regenerative braking system under different SOC conditions and analyzing the impact of the SOC conditions on the braking safety performance of the regenerative braking system to ensure comprehensive test results.

[0035] In this embodiment, optionally, the method further includes: adjusting the test environment to continue the test, so as to evaluate the safety performance of the regenerative braking system under different test environments.

[0036] Specifically, various environmental parameters of the test vehicle's environment, such as ambient temperature, atmospheric pressure, wind speed, relative humidity, etc., can also be adjusted, and the test can continue according to the above test steps to obtain the braking safety performance of the regenerative braking system under different test environments, so as to analyze the impact of environmental factors on the braking safety performance of the regenerative braking system and ensure the comprehensiveness of the test results.

[0037] In this embodiment, optionally, the method further includes: adjusting the braking intensity of the regenerative braking system to continue testing, so as to evaluate the safety performance of the regenerative braking system under different braking intensities.

[0038] Specifically, after obtaining the braking safety performance of the regenerative braking system at the currently set initial braking speed, the braking intensity of the regenerative braking system of the test vehicle can also be adjusted, and the test can continue according to the above test steps to obtain the braking safety performance of the regenerative braking system under different braking intensities, so as to analyze the impact of braking intensity on the braking safety performance of the regenerative braking system and ensure the comprehensiveness of the test results.

[0039] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.

Claims

1. A safety performance test and evaluation method for an electric vehicle regenerative braking system, characterized in that: include: Select a test road with the corresponding road adhesion coefficient according to the test requirements, and set the test environment, initial braking speed, braking position, as well as the vehicle status and braking method of the test vehicle; Driving the test vehicle along a test road, and when the test vehicle reaches a braking position, braking the test vehicle according to a set initial braking speed and braking mode; Various test data of the test vehicle during the braking process are detected in real time, and the safety performance of the regenerative braking system is evaluated based on the various test data.

2. The safety performance testing and evaluation method for the regenerative braking system of an electric vehicle according to claim 1, characterized in that: The braking mode is set according to the type of the regenerative braking system installed in the test vehicle.

3. The safety performance testing and evaluation method of the electric vehicle regenerative braking system according to claim 1 is characterized in that: The braking positions include: the position where the speed of the test vehicle on the low adhesion coefficient road surface reaches the initial braking speed, the position where the wheels enter the low adhesion coefficient road surface from the high adhesion coefficient road surface, the position where the left and right wheels enter two road surfaces with different adhesion coefficients, and / or a flat arc lane.

4. The safety performance testing and evaluation method of the electric vehicle regenerative braking system according to claim 1, characterized in that: Also includes: The set driving speed of the test vehicle is adjusted to continue the test to evaluate the safety performance of the regenerative braking system at different driving speeds.

5. The safety performance testing and evaluation method of the electric vehicle regenerative braking system according to claim 1 is characterized in that: Also includes: The vehicle state of the test vehicle is adjusted to continue the test to evaluate the safety performance of the regenerative braking system under different vehicle states.

6. The safety performance testing and evaluation method of the electric vehicle regenerative braking system according to claim 1 is characterized in that: Also includes: The test environment is adjusted to continue the test to evaluate the safety performance of the regenerative braking system under different test environments.

7. The safety performance testing and evaluation method of the electric vehicle regenerative braking system according to claim 1, characterized in that: Also includes: The braking intensity of the regenerative braking system is adjusted and the test is continued to evaluate the safety performance of the regenerative braking system under different braking intensities.

8. The safety performance testing and evaluation method for the electric vehicle regenerative braking system according to claim 1 is characterized in that: The safety performance of the regenerative braking system is evaluated based on various test data, including: The wheel slip ratio is calculated based on the acquired test data, and the safety performance of the regenerative braking system is evaluated by the wheel slip ratio.

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