New energy four-wheel-drive vehicle type anti-skid test system and test method based on whole vehicle state

Abstract

The invention discloses a new energy four-wheel-drive vehicle type anti-skid test system and test method based on the whole vehicle state. The system comprises a test vehicle, a four-motor rack, a torque sensor, a rotating speed sensor and a signal acquisition system. An electric drive assembly is arranged in the test vehicle; the four-motor rack comprises four load dynamometers; input shafts of the four load dynamometers are respectively connected with four transmission half shafts or four hubs of a tested vehicle through a torque sensor; a rotating speed sensor is arranged in each load dynamometer; the rotating speed sensor is connected with an input shaft of the load dynamometer; and the data acquisition system is respectively connected with the torque sensor and the rotating speed sensor and is used for obtaining the slip rate of the tested vehicle. According to the invention, the anti-skid performance of the new energy four-wheel drive vehicle can be tested in the whole vehicle state, the problems that the implementation difficulty is large and the test working condition cannot be reproduced on an actual road are effectively solved, and the influence on the environment is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy four-wheel drive vehicle models, and particularly to an anti-skid test system and test method for new energy four-wheel drive vehicle models based on the vehicle state. Background Art

[0002] The development trend of new energy vehicles is becoming increasingly rapid, and high-performance new energy four-wheel drive vehicle models have emerged one after another. Therefore, the anti-skid performance of new energy four-wheel drive vehicle models is particularly important.

[0003] Currently, for the anti-skid test of new energy four-wheel drive vehicle models, it is all carried out on actual roads. The test process is relatively complex and can only be tested on actual roads. However, this test method cannot accurately control the required working condition points and is difficult to implement. It is also impossible to reproduce the test working conditions, and the influence factors of the environment are relatively large, making it often impossible to effectively optimize the anti-skid performance of the vehicle models developed by vehicle manufacturers.

[0004] Therefore, there is an urgent need to develop a technology that can test the anti-skid performance of new energy four-wheel drive vehicle models in the vehicle state. Summary of the Invention

[0005] The purpose of the present invention is to provide an anti-skid test system and test method for new energy four-wheel drive vehicle models based on the vehicle state in view of the technical defects existing in the prior art.

[0006] To this end, the present invention provides an anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state, which is characterized by including a test vehicle, a four-motor bench, a torque sensor, a rotational speed sensor, and a signal acquisition system;

[0007] An electric drive assembly is provided in the test vehicle;

[0008] The four-motor bench includes four load dynamometers;

[0009] The input shafts of the four load dynamometers are respectively connected to the four drive half shafts or four wheels of the test vehicle through a torque sensor;

[0010] The four torque sensors are used to measure the output torque of the drive half shaft or wheel of the test vehicle in real time, that is, to measure the output torque of the electric drive assembly, and send the output torque of the electric drive assembly as the actual wheel-end torque of the test vehicle to the data acquisition system;

[0011] A rotational speed sensor is respectively provided in each load dynamometer;

[0012] A rotational speed sensor is connected to the input shaft of the load dynamometer and is used to obtain the output rotational speed of the drive half shaft or wheel hub of the test vehicle connected to the input shaft by measuring the rotational speed of the input shaft of the load dynamometer, that is, to obtain the rotational speed of the electric drive assembly, and send the rotational speed of the electric drive assembly as the actual output wheel rotational speed of the test vehicle to the data acquisition system;

[0013] A data acquisition system is communicatively connected to the torque sensor and the rotational speed sensor respectively and is used to collect and store in real time the actual wheel end torque and the actual output wheel rotational speed of the test vehicle and calculate the slip ratio of the test vehicle.

[0014] In addition, the present invention also provides a test method for an anti-skid test system of a new energy four-wheel drive vehicle model based on the vehicle state as described above, including the following steps:

[0015] Step S1, set a test target condition matrix (Vi, Wj) for the test vehicle 6, and the test target condition matrix includes a plurality of different target vehicle speeds Vi and a plurality of different target wheel rotational speeds Wj;

[0016] There is a one-to-many mapping relationship between the target vehicle speed Vi and the target wheel rotational speed Wj;

[0017] The test target condition matrix includes a plurality of condition points;

[0018] Each condition point includes a target vehicle speed Vi and a target wheel rotational speed Wj corresponding to the target vehicle speed Vi;

[0019] Step S2, preheat the test vehicle: after the test vehicle is connected to the four-motor bench, the driver drives the test vehicle to travel at a preset vehicle speed at a constant speed for a preset mileage to complete the preheating of the test vehicle;

[0020] Step S3, adjust the actual vehicle speed and the theoretical output wheel rotational speed of the test vehicle to be equal to the target vehicle speed Vi and the target wheel rotational speed Wj of each condition point in the test target condition matrix respectively;

[0021] Step S4, for the test vehicle 6 under each condition point, obtain the actual vehicle speed V(i, j), the theoretical output wheel rotational speed W(i, j) and the output torque of the electric drive assembly in the test vehicle, and then calculate the slip ratio of the test vehicle.

[0022] As can be seen from the technical solutions provided by the present invention above, compared with the prior art, the present invention provides an anti-skid test system and a test method for a new energy four-wheel drive vehicle model based on the vehicle state, which is scientifically designed and can test the anti-skid performance of the new energy four-wheel drive vehicle model under the vehicle state, effectively solve the problems of great implementation difficulty on the actual road and inability to reproduce the test conditions, and reduce the influence of the environment, and has great practical significance. Description of the Drawings

[0023] Figure 1 This is the overall structural block diagram of a new energy four-wheel drive vehicle anti-skid test system based on the vehicle state provided by the present invention;

[0024] Figure 2 This is the basic flowchart of the test method of a new energy four-wheel drive vehicle anti-skid test system based on the vehicle state provided by the present invention;

[0025] Figure 3 This is the overall flowchart of an embodiment of the test method of a new energy four-wheel drive vehicle anti-skid test system based on the vehicle state provided by the present invention;

[0026] In the figure, 1 - load dynamometer; 2 - torque sensor; 3 - speed sensor; 4 - left front electric drive assembly; 5 - right front electric drive assembly; 6 - test vehicle; 7 - left rear electric drive assembly - 8 - right rear electric drive assembly; 9 - signal acquisition system. Detailed Description of the Invention

[0027] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0029] In the description of this patent, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", "connection", "setting" should be understood in a broad sense. For example, it can be fixedly connected and set, or detachably connected and set, or integrally connected and set. For those of ordinary skill in the art, the specific meanings of the above terms in this patent can be understood according to specific circumstances.

[0030] In addition, the terms "first" and "second" are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0031] To enable those skilled in the art of this technology to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

[0032] See Figure 1 , the present invention provides an anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state, including a test vehicle 6, a four-motor bench, torque sensors 2, speed sensors 3, and a signal acquisition system 9;

[0033] An electric drive assembly is provided inside the test vehicle 6;

[0034] The four-motor bench includes four load dynamometers 1 (i.e., load motors);

[0035] The input shafts of the four load dynamometers 1 are respectively connected to the four drive half shafts (i.e., the drive half shafts originally used to connect to the wheels) or four wheels of the test vehicle 6 through a torque sensor 2 (specifically, mechanically connected through a flange);

[0036] The four torque sensors 2 are used to measure the output torque of the drive half shafts or wheels of the test vehicle 6 in real time, that is, to measure the output torque of the electric drive assembly, and send the output torque of the electric drive assembly as the actual wheel-end torque of the test vehicle 6 to the data acquisition system 9;

[0037] It should be noted that for the present invention, a torque sensor is installed on each output wheel end of the test vehicle 6.

[0038] A speed sensor (i.e., vehicle speed sensor) 3 is respectively provided inside each load dynamometer 1;

[0039] The speed sensor 3 is connected to the input shaft of the load dynamometer 1 and is used to obtain the output speed of the drive half shaft or wheel of the test vehicle 6 connected to the input shaft by measuring the input shaft speed of the load dynamometer 1, that is, to obtain the speed of the electric drive assembly, and send the speed of the electric drive assembly as the actual output wheel speed of the test vehicle 6 to the data acquisition system 9;

[0040] The data acquisition system 9 is communicatively connected to the torque sensor 2 and the rotational speed sensor (i.e., vehicle speed sensor) 3 respectively, and is used to collect and store in real time the actual wheel-end torque and the actual output wheel rotational speed of the test vehicle 6 (i.e., the output torque of the electric drive assembly and the measured rotational speed of the rotational speed sensor 3), and calculate the slip ratio of the test vehicle 6.

[0041] It should be noted that the electric drive assembly and the drive half shaft are well-known components with mature technologies on existing new energy vehicles (electric vehicles), and will not be elaborated here.

[0042] In the present invention, specifically, at the bottom of each load dynamometer 1 included in the four-motor test bench, they are respectively arranged on an external horizontal installation platform through vertically distributed dynamometer brackets.

[0043] In the present invention, specifically, the electric drive assembly includes a left front drive assembly 4 arranged at the left front part of the test vehicle, a right front drive assembly 5 arranged at the right front part of the test vehicle, a rear electric drive assembly 7 arranged at the left rear part of the test vehicle, and a left front drive assembly 8 arranged at the right rear part of the test vehicle;

[0044] Specifically, the four wheels of the test vehicle 6 are respectively connected to the torque sensor 2 connected to the input shaft of the load dynamometer 1 in the four-motor test bench through a flange tooling (such as a flange).

[0045] It should be noted that the four-motor test bench, that is, the four-wheel drive power assembly test bench, is a test bench with mature existing technologies. Specifically, the four-wheel drive power assembly test bench produced by AVL Company of Austria can be adopted for carrying out working condition tests, and will not be elaborated here; among them, the control system installed on the four-wheel drive power assembly test bench is used to control the four load dynamometers 1 to run at a preset rotational speed, so as to realize the control of the vehicle speed. When the vehicle speed increases, the load dynamometer 1 uses AC frequency conversion to adjust the rotational speed of the wheel end in real time.

[0046] It should be noted that the four-motor test bench is an indoor test bench equipment used to test the performance of an automobile such as power performance, multi-condition fuel economy, pure electric driving range, and pure electric energy consumption. The four-motor test bench simulates the road resistance and uses a loading device for simulation to realize the simulation of various working conditions of the automobile. The test vehicle 6 is connected to the four-motor test bench for simulated driving. Since the wheels of the test vehicle 6 need to be removed when driving on the four-motor test bench, during the test, the test vehicle 6 can be conveniently connected to various detection devices for measurement.

[0047] Specifically, the installation height of the output shaft of the electric drive assembly of the test vehicle 6 is the same as that of the input shaft of the load dynamometer 1 of the four-motor test bench.

[0048] It should be noted that when the electric drive assembly is a four-wheel drive electric drive assembly, the four drive half shafts of the test vehicle 6 may not be equipped with the original vehicle wheels and braking systems. The chassis of the test vehicle 6 is supported by four vertically distributed height-adjustable brackets, and the height of the output shaft of the electric drive assembly of the test vehicle 6 is adjusted to be the same as the height of the input shaft of the load dynamometer 1 of the four-motor bench.

[0049] It should be noted that since the original vehicle wheels, braking systems, and wheel hubs are not installed on the four drive half shafts of the test vehicle 6, the influence of the braking system drag resistance and the internal resistance of the wheel hub bearings on the output torque test of the half shaft can be effectively avoided, and the output torque at the half shaft end of the electric drive assembly can be directly tested.

[0050] In the present invention, specifically, a first coupling is provided between one end of the torque sensor 2 and the wheel hub of the test vehicle 6;

[0051] A second coupling is provided between the other end of the torque sensor 2 and the input shaft of the load dynamometer 1.

[0052] In the present invention, specifically, the control wire harness of the throttle on the test vehicle 6 is connected to the controller provided on the four-motor bench, so that the acceleration pedal and the brake pedal on the test vehicle 6 can be controlled through the four-motor bench.

[0053] In the present invention, specifically, the data acquisition system 9 is used to calculate the slip ratio of the test vehicle 6 according to a preset slip ratio calculation formula;

[0054] The preset slip ratio calculation formula is specifically as follows:

[0055] S = (v - w) / v × 100%, Formula (1);

[0056] Wherein, v represents the speed (m / s) of the test vehicle 6 traveling on the ground, that is, the actual vehicle speed V(i, j) of the test vehicle 6, which is equal to the product of the rotational speed of the input shaft of the load dynamometer 1 (i.e., the measured value of the rotational speed sensor 3, that is, the actual output wheel rotational speed of the test vehicle 6) and the circumference of the wheels (including tires and wheel hubs) of the test vehicle 6;

[0057] w represents the theoretical output vehicle speed (i.e., wheel speed, m / s) of the test vehicle 6, that is, the product of the theoretical output wheel rotational speed W(i, j) displayed on the tachometer of the test vehicle 6 and the circumference of the wheels (including tires and wheel hubs) of the test vehicle 6, that is, the product of the wheel rotational speed that the power system of the test vehicle 6 hopes to output outward and the circumference of the wheels (including tires and wheel hubs) of the test vehicle 6.

[0058] It should be noted that when the wheel is in a pure rolling state, the slip ratio S = 0; and when the wheel is locked and sliding, at this time the slip ratio S = 100%.

[0059] It should be noted that the data acquisition system 9 is connected to the controller of the test vehicle 6 itself and can obtain the theoretical wheel speed W(i, j) displayed on the tachometer of the test vehicle 6.

[0060] It should be noted that the slip ratio of a test vehicle refers to the slip phenomenon that occurs between the tire tread and the road surface when the vehicle's tires are braking or accelerating straight. It is an important parameter characterizing the vehicle's grip. The size of the vehicle's slip ratio is closely related to the vehicle's anti-skid performance. When the slip ratio is within a reasonable range (for example, between 15% and 25%), the vehicle has better anti-skid performance. Beyond the reasonable range, the anti-skid performance decreases. When the slip ratio is too small, it means that the wheel is close to the pure rolling state and the adhesion between the wheel and the ground is not fully utilized. When the slip ratio is too large, the wheel is in an over-sliding state.

[0061] Based on the above-mentioned anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle's overall state provided by the present invention, refer to Figure 2 、 Figure 3 The present invention also provides a test method for the anti-skid test system of new energy four-wheel drive vehicle models based on the vehicle's overall state, which specifically includes the following steps:

[0062] Step S1, set the test target working condition matrix (Vi, Wj) of the test vehicle 6, and this test target working condition matrix includes multiple different target vehicle speeds Vi and multiple different target wheel speeds Wj;

[0063] There is a one-to-many mapping relationship between the target vehicle speed Vi and the target wheel speed Wj;

[0064] The test target working condition matrix includes multiple working condition points;

[0065] Each working condition point includes a target vehicle speed Vi and a target wheel speed Wj corresponding to this target vehicle speed Vi;

[0066] It should be noted that in the matrix, i and j usually represent the position indexes of the elements. i: represents the row where the element is located (Row), starting from 1 (starting from 0 in some scenarios). j: represents the column where the element is located (Column), starting from 1 (starting from 0 in some scenarios).

[0067] It should be noted that for the present invention, the test target working condition matrix includes multiple different skidding scenario working condition points; each skidding scenario working condition point contains a target vehicle speed Vi and a target wheel speed Wj; the multiple different skidding scenario working condition points include multiple different target vehicle speeds Vi and corresponding multiple different target wheel speeds Wj.

[0068] Multiple different skidding scenario operating points, specifically including inputting different wheel speeds to the four drive half shafts or wheels of the test vehicle 6 through a four-motor bench to simulate eight situations where a single wheel, a single-side wheel, or diagonal wheels of the test vehicle 6 skid (four vehicle skids, two single-side wheel skids, and two pairs of diagonal wheel skids respectively). The simulated scenario operating conditions include six scenario operating conditions such as single front wheel skid, single rear wheel skid, front axle skid, rear axle skid, single-side skid, and cross-axle skid, and the target skidding wheel is controlled through different scenarios.

[0069] It should be noted that generally, vehicles have several different driving modes, and tests need to be carried out for different driving modes during the test process.

[0070] In the present invention, specifically, the value range of the multiple target vehicle speeds Vi included in the test target condition matrix (Vi, Wj) is: 10 km / h - 60 km / h, and the difference (i.e., interval) between two adjacent target vehicle speeds Vi with similar values is 10 km / h;

[0071] Specifically, for the test target condition matrix (Vi, Wj), there may be a total of 6 target vehicle speeds, so i = 6;

[0072] In the present invention, specifically, the value range of the multiple target wheel speeds Wj (i.e., target wheel speeds) included in the test target condition matrix (Vi, Wj) is: 0 rpm - 200 rpm (revolutions per minute), and the difference (i.e., interval) between two adjacent target wheel speeds Wj with similar values is 10 rpm;

[0073] Specifically, for the test target condition matrix (Vi, Wj), there may be a total of 20 target wheel speeds, so j = 20, thus obtaining the test condition matrix (Vi, Wj) of the vehicle speed and wheel speed of the test vehicle 6, and repeated tests need to be carried out according to different driving modes and different skidding scenarios of the vehicle.

[0074] It should be noted that according to the tire rolling radius (i.e., wheel radius) of the test vehicle 6, the wheel speed corresponding to different driving vehicle speeds can be calculated, and the quotient obtained by dividing the target vehicle speed Vi of the test vehicle 6 by the tire rolling radius (i.e., wheel radius) is equal to the target wheel speed Wj of the test vehicle 6.

[0075] In the present invention, specifically, before setting the test target condition matrix of the test vehicle 6, it is necessary to refer to Figure 1 As shown, set up a four-motor bench.

[0076] Step S2, preheating the test vehicle: After the test vehicle 6 is connected to the four-motor test bench, the driver drives the test vehicle 6 at a preset speed and a preset mileage to complete the preheating of the test vehicle 6;

[0077] In step S2, in specific implementation, the test vehicle 6 is preheated by running at a constant speed of 80 km / h for 30 minutes on a four-motor test bench. At this time, the lubricating oil and liquid of the electric drive assembly have reached a hot engine state.

[0078] Step S3, adjusting the actual vehicle speed of the test vehicle 6 (i.e., the vehicle speed calculated based on the measurement value of the speed sensor 3 connected to the test vehicle 6) and the theoretical output wheel speed (i.e., the wheel speed displayed on the tachometer of the test vehicle 6) to be equal to the target vehicle speed Vi and target wheel speed Wj for each operating point in the test target operating condition matrix;

[0079] In the present invention, step S3 specifically includes the following steps:

[0080] Step S31: For any operating point in the test target operating condition matrix, adjust the input shaft speed of the load dynamometer 1 to match the target vehicle speed Vi at that operating point, so that the actual vehicle speed V of the test vehicle 6 reaches the target vehicle speed Vi specified in that operating point and maintains stable driving at the target vehicle speed Vi.

[0081] In step S31, in specific implementation, the actual vehicle speed V of the test vehicle 6 is equal to the product of the input shaft speed of the load dynamometer 1 (i.e., the measurement value of the speed sensor 3, i.e., the actual output wheel speed of the test vehicle 6) and the circumference of the wheel (including the tire and the wheel hub) of the test vehicle 6;

[0082] It should be noted that the circumference of the wheel (including the tire and the wheel hub) of the test vehicle 6 is C=2πr, where r is the wheel radius of the test vehicle 6 .

[0083] Step S32, for any operating point in the test target operating condition matrix (for example, different slip scenario operating points), the driver drives the test vehicle 6 so that the theoretical output wheel speed of the test vehicle 6 (that is, the wheel speed displayed on the tachometer of the test vehicle 6) reaches the target wheel speed Wj specified in the operating point (specifically achieved by the driver through operational control, which can be obtained from the tachometer display on the test vehicle 6), and keeps the theoretical output wheel speed of the test vehicle 6 stable at the target wheel speed Wj (that is, the target value).

[0084] Step S4, for the test vehicle 6 at each operating point, obtain the actual vehicle speed V(i, j), the theoretical output wheel speed W(i, j) and the output torque of the electric drive assembly in the test vehicle 6 (the wheel end torque of the four wheels of the test vehicle), and then calculate the slip rate of the test vehicle 6.

[0085] In the present invention, step S4 specifically includes the following operations:

[0086] Step S41, for the test vehicle 6 at each operating point, the output torque of the electric drive assembly in the test vehicle 6 and the actual output wheel speed of the test vehicle 6 are obtained respectively through the torque sensor 2 and the speed sensor (i.e., the vehicle speed sensor) 3, and then the actual vehicle speed V(i, j) of the test vehicle 6 is obtained, and according to the theoretical output wheel speed W(i, j) displayed on the test vehicle 6 (obtained from the tachometer displayed on the test vehicle 6), the slip rate S of the slipping wheel side of the test vehicle 6 is calculated through the data acquisition system 9.

[0087] In addition, step S4 further includes the following steps:

[0088] Step S42, record the output torque of the electric drive assembly in the test vehicle 6 (i.e., the data of the four wheel-end torques during the experiment). By recording this output torque data, it is used to observe the changes in the wheel-end torque during the vehicle slippage, thereby observing the vehicle state of the test vehicle 6 during the test process for further data analysis.

[0089] In the present invention, step S41 specifically includes the following operations:

[0090] Step S411: After the actual vehicle speed V and the theoretical output wheel speed W of the test vehicle 6 are adjusted until they are equal to a certain operating point in the test target operating condition matrix, and after the test vehicle 6 enters a steady state and maintains a preset stable time (e.g., 10 seconds), the actual output wheel speed and output torque of the test vehicle 6 are measured by the speed sensor 2 and the torque sensor 3 for a preset test time T (e.g., 10 seconds), and the actual vehicle speed V(i, j) of the test vehicle 6 at the operating point and within the preset test time T is obtained, as well as the theoretical output wheel speed W(i, j) of the test vehicle 6 (as displayed by the tachometer on the test vehicle 6);

[0091] It should also be noted that the actual vehicle speed V of the test vehicle 6 is equal to the product of the input shaft speed of the load dynamometer 1 (i.e., the measurement value of the speed sensor 3, i.e., the actual output wheel speed of the test vehicle 6) and the circumference of the wheel (including the tire and wheel hub) of the test vehicle 6;

[0092] Among them, the theoretical output vehicle speed of the test wheel 6 is equal to the product of the theoretical output wheel speed W(i, j) of the test vehicle 6 and the circumference of the wheels (including tires and wheels) of the test vehicle 6, that is, the product of the wheel speed that the power system of the test vehicle 6 hopes to output externally and the circumference of the wheels (including tires and wheels) of the test vehicle 6.

[0093] Step S412: Calculate the slip ratio S(i, j) of the test vehicle 6 within the preset test duration T according to the preset slip ratio calculation formula.

[0094] It should be noted that for a vehicle, the motion state of the vehicle caused by the input can be divided into two types: steady state that does not change with time and transient state that changes with time. The corresponding vehicle responses are steady-state response and transient response respectively, and the states of the vehicle are divided into steady state and transient state.

[0095] In the present invention, in step S412, the preset slip ratio calculation formula is specifically as follows:

[0096] S = (v - w) / v × 100%, formula (1);

[0097] Among them, v represents the speed (m / s) of the test vehicle 6 traveling on the ground, that is, the actual vehicle speed V(i, j) of the test vehicle 6, which is equal to the product of the input shaft speed of the load dynamometer 1 (i.e., the measured value of the speed sensor 3) and the circumference of the wheels (including tires and wheels) of the test vehicle 6;

[0098] w represents the theoretical output vehicle speed of the test vehicle 6 (i.e., wheel speed, m / s), that is, the product of the theoretical output wheel speed W(i, j) displayed on the tachometer of the test vehicle 6 and the circumference of the wheels (including tires and wheels) of the test vehicle 6, that is, the product of the wheel speed that the power system of the test vehicle 6 hopes to output externally and the circumference of the wheels (including tires and wheels) of the test vehicle 6.

[0099] It should be noted that when the wheel is in a pure rolling state, v = w and the slip ratio S = 0; while when the wheel is locked and sliding, the theoretical output vehicle speed w of the test vehicle 6 = 0, and at this time the slip ratio S = 100%.

[0100] It should be noted that the slip ratio of the test vehicle refers to the slip phenomenon generated between the tire tread and the road surface when the vehicle's tires are braking or accelerating straight. It is an important parameter characterizing the vehicle's grip. The size of the vehicle's slip ratio is closely related to the vehicle's anti-skid performance. When the slip ratio is within a reasonable range (for example, between 15% and 25%), the vehicle's anti-skid performance is better. If it exceeds the reasonable range, the anti-skid performance will decline. When the slip ratio is too small, it means that the wheel is close to a pure rolling state and the adhesion between the wheel and the ground is not fully utilized. When the slip ratio is too large, the wheel is in an over-sliding state.

[0101] Compared with the prior art, the present invention has the following beneficial technical effects:

[0102] 1. The present invention is tested on a four-motor test bench. A test method for the anti-skid performance of new energy four-wheel drive vehicles is proposed in the whole vehicle state. According to different skidding scenario working condition points, the test vehicle is controlled by the four-motor test bench to reach the set target working condition (that is, to reach the target vehicle speed Vi and target wheel speed Wj corresponding to this working condition point). Then, the wheel-end speed and the driving motor torque are simultaneously tested through a torque sensor and a speed sensor, and the slip ratio of the corresponding test working condition is calculated. The test is simple;

[0103] 2. The present invention is more convenient and accurate for testing the anti-skid performance of new energy four-wheel drive vehicles in the whole vehicle state;

[0104] 3. For the technical solution of the present invention, the working conditions are easy to reproduce, the test accuracy is high, and the operation is convenient. By connecting the four-motor test bench with the test vehicle, the practicability is strong. It is not necessary to conduct actual road experiments to detect the actual vehicle speed and the theoretical output vehicle speed of the test vehicle, and then obtain the slip ratio S of the test vehicle 6, which is beneficial to mastering the anti-skid performance of the test vehicle and reducing the influence of the external environment during actual road experiments.

[0105] In summary, compared with the prior art, the present invention provides an anti-skid test system and test method for new energy four-wheel drive vehicles based on the whole vehicle state. Its design is scientific, and it can test the anti-skid performance of new energy four-wheel drive vehicles in the whole vehicle state, effectively solving the problems of great difficulty in implementation on actual roads and inability to reproduce test working conditions, and reducing the influence of the environment, which has great practical significance.

[0106] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A four-wheel drive new energy vehicle anti-skid test system based on the vehicle state, characterized in that It includes a test vehicle (6), a four-motor bench, a torque sensor (2), a speed sensor (3), and a signal acquisition system (9); An electric drive assembly is provided inside the test vehicle (6); The four-motor bench includes four load dynamometers (1); The input shafts of the four load dynamometers (1) are respectively connected to the four drive half shafts or four wheels of the test vehicle (6) through a torque sensor (2); The four torque sensors (2) are used to measure in real time the output torque of the drive half shaft or wheel of the test vehicle (6), that is, to measure the output torque of the electric drive assembly, and send the output torque of the electric drive assembly as the actual wheel-end torque of the test vehicle (6) to the data acquisition system (9); A speed sensor (3) is respectively provided inside each load dynamometer (1); The speed sensor (3) is connected to the input shaft of the load dynamometer (1), and is used to obtain the output speed of the drive half shaft or wheel of the test vehicle (6) connected to the input shaft by measuring the input shaft speed of the load dynamometer (1), that is, to obtain the speed of the electric drive assembly, and send the speed of the electric drive assembly as the actual output wheel speed of the test vehicle (6) to the data acquisition system (9); The data acquisition system (9) is respectively communicatively connected to the torque sensor (2) and the speed sensor (3), and is used to collect and store in real time the actual wheel-end torque and the actual output wheel speed of the test vehicle (6), and calculate the slip ratio of the test vehicle (6).

2. The anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 1, characterized in that, The electric drive assembly includes a left front drive assembly (4) provided at the left front of the test vehicle, a right front drive assembly (5) provided at the right front of the test vehicle, a rear electric drive assembly (7) provided at the left rear of the test vehicle, and a left front drive assembly (8) provided at the right rear of the test vehicle.

3. The anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 1, characterized in that, The four wheels of the test vehicle (6) are respectively connected to the torque sensors (2) connected to the input shafts of the load dynamometers (1) in the four-motor bench through flanges; and / or The installation height of the output shaft of the electric drive assembly of the test vehicle (6) is the same as that of the input shaft of the load dynamometer (1) of the four-motor bench; and / or A first coupling is provided between one end of the torque sensor (2) and the wheel of the test vehicle (6); A second coupling is provided between the other end of the torque sensor (2) and the input shaft of the load dynamometer (1).

4. The anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 1, wherein, The data acquisition system (9) is used to calculate the slip ratio of the test vehicle (6) according to a preset slip ratio calculation formula; The preset slip ratio calculation formula is specifically as follows: S = (v - w) / v × 100%, formula (1); Wherein, v represents the speed of the test vehicle (6) traveling on the ground, that is, the actual vehicle speed V(i, j) of the test vehicle (6), which is equal to the product of the input shaft speed of the load dynamometer (1) and the wheel circumference of the test vehicle (6); w represents the theoretical output vehicle speed of the test vehicle (6), that is, the product of the theoretical output wheel speed W(i, j) displayed on the tachometer of the test vehicle (6) and the wheel circumference of the test vehicle (6).

5. A testing method for an anti-skid testing system of a new energy four-wheel drive vehicle model based on the vehicle's overall state as described in any one of claims 1 to 4, characterized in that, It includes the following steps: Step S1, set the test target working condition matrix (Vi, Wj) of the test vehicle (6), where the test target working condition matrix includes multiple different target vehicle speeds Vi and multiple different target wheel speeds Wj; There is a one-to-many mapping relationship between the target vehicle speed Vi and the target wheel speed Wj; The test target working condition matrix includes multiple working condition points; Each working condition point includes a target vehicle speed Vi and a target wheel speed Wj corresponding to the target vehicle speed Vi; Step S2, preheat the test vehicle: After the test vehicle (6) is connected to the four-motor bench, the driver drives the test vehicle (6) to travel at a preset vehicle speed at a constant speed for a preset mileage to complete the preheating of the test vehicle (6); Step S3, adjust the actual vehicle speed and the theoretical output wheel speed of the test vehicle (6) to be equal to the target vehicle speed Vi and the target wheel speed Wj of each working condition point in the test target working condition matrix respectively; Step S4, for the test vehicle (6) at each working condition point, obtain the actual vehicle speed V(i, j), the theoretical output wheel speed W(i, j) of the test vehicle (6), and the output torque of the electric drive assembly in the test vehicle (6), and then calculate the slip ratio of the test vehicle (6).

6. The test method of the anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 5, characterized in that, In step S2, the test vehicle (6) travels at a constant speed of 80 km / h on the four-motor bench for 30 minutes for preheating. At this time, the lubricating oil and liquid of the electric drive assembly reach the hot engine state.

7. The test method of the anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 5, characterized in that, The said step S3 includes the following steps: Step S31, for any working condition point in the test target working condition matrix, adjust the input shaft speed of the load dynamometer (1) to match the target vehicle speed Vi of this working condition point, so that the actual vehicle speed V of the test vehicle (6) reaches the target vehicle speed Vi specified in this working condition point and maintains a stable travel at the target vehicle speed Vi; Step S32, for any working condition point in the test target working condition matrix, the driver drives the test vehicle (6) so that the theoretical output wheel speed of the test vehicle (6) reaches the target wheel speed Wj specified in this working condition point, and maintains the theoretical output wheel speed of the test vehicle (6) stable at the target wheel speed Wj.

8. The test method of the anti-skid test system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 5, characterized in that, The said step S4 includes the following operations: Step S41, for the test vehicle (6) at each working condition point, obtain the output torque of the electric drive assembly in the test vehicle (6) and the actual output wheel speed of the test vehicle (6) respectively through the torque sensor (2) and the speed sensor (3), so as to obtain the actual vehicle speed V(i, j) of the test vehicle (6), and according to the theoretical output wheel speed W(i, j) displayed on the test vehicle (6), calculate the slip ratio S of the pulley side of the test vehicle (6) through the data acquisition system (9).

9. The testing method of the anti-skid testing system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 8, characterized in that, Step S41 specifically includes the following operations: Step S411: When adjusting the actual vehicle speed V and the theoretical output wheel speed W of the test vehicle (6) until they are equal to a certain operating condition point in the test target operating condition matrix, and after the test vehicle (6) enters a steady state and lasts for a preset steady duration, measure the actual output wheel speed and output torque of the test vehicle (6) for a preset test duration T through the speed sensor (2) and the torque sensor (3) respectively, to obtain the actual vehicle speed V(i, j) of the test vehicle (6) at this operating condition point within the preset test duration T, and obtain the theoretical output wheel speed W(i, j) of the test vehicle (6) from the test vehicle (6). Step S412: Calculate the slip ratio S(i, j) of the test vehicle 6 within the preset test duration T according to the preset slip ratio calculation formula.

10. The testing method of the anti-slip testing system for new energy four-wheel drive vehicle models based on the vehicle state according to claim 9, characterized in that, In step S412, the preset slip ratio calculation formula is specifically as follows: S = (v - w) / v × 100%, formula (1); where, v represents the speed of the test vehicle (6) traveling on the ground, that is, the actual vehicle speed V(i, j) of the test vehicle (6), which is equal to the product of the input shaft speed of the load dynamometer (1) and the wheel circumference of the test vehicle (6); w represents the theoretical output vehicle speed of the test vehicle (6), that is, the product of the theoretical output wheel speed W(i, j) displayed on the tachometer of the test vehicle (6) and the wheel circumference of the test vehicle (6).

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