A Preset-Time Vehicle Cooperative Control Method Based on Power Drive Fault

Abstract

This invention provides a preset-time vehicle cooperative control method based on power drive faults, relating to the field of intelligent transportation technology. It introduces model transformation to convert underdriven vehicle models into fully driven vehicle models, and then performs cooperative control based on longitudinal and lateral vehicle spacing. Considering the impact of power drive faults, a variable-time spacing strategy with a fault information lower bound is designed, which can guarantee zero initial spacing error and avoid unnecessary losses caused by the continuous change of the exponential factor in the few spacing strategies that can guarantee zero initial spacing error. For two-dimensional vehicle fleets with power drive faults, a preset-time sliding mode controller based on model transformation and a variable-time spacing strategy with a fault information lower bound is designed to ensure that the position cooperative error converges to a small neighborhood of zero within a preset time, with the upper bound of the convergence time being a simple parameter.

Description

Technical Field

[0001] This invention relates to the field of intelligent transportation technology, and in particular to a pre-set time vehicle cooperative control method based on power drive failure. Background Technology

[0002] Vehicle cooperative control, as an important branch of intelligent transportation systems, has received considerable attention in recent years. Currently, most research on vehicle cooperative control focuses on single longitudinal control, which is unsuitable for real-world scenarios such as multi-lane merging and curves, thus having limitations. Existing research on longitudinal and lateral cooperative control is mostly based on the distance between vehicle centers of gravity and the positional angle between vehicles, without establishing a connection with the steering angle of the preceding vehicle. This leads to uncertainty in the following vehicle trajectory and introduces singularity problems. Furthermore, the spacing strategies used in longitudinal and lateral cooperative control research are mostly constant spacing strategies, and many studies assume that the initial spacing between vehicles in the platoon is the desired spacing, i.e., the initial spacing error is zero. However, in actual engineering, the initial spacing error between vehicles in the platoon is often not zero, making this assumption unreasonable and unrealistic. Some studies have designed spacing strategies that can guarantee zero initial spacing error for longitudinal platoons, but these use exponential factors, causing the desired spacing to change continuously, requiring continuous adjustments by the controller and accelerating component wear. In addition, few strategies consider the impact of power drive failures. Furthermore, vehicle cooperative control requires a high speed to achieve the desired control objective, and asymptotic convergence and exponential convergence often fail to meet practical requirements. Some studies have designed finite-time longitudinal and lateral vehicle cooperative control methods, but their convergence time is a complex function closely related to the initial state of the vehicle and the control parameters, making it difficult to adjust the upper bound of the convergence time.

[0003] Current research on vehicle cooperative control primarily focuses on single longitudinal platoons, with limited research on longitudinal-lateral cooperative control. The few existing studies on longitudinal-lateral cooperative control often suffer from trajectory uncertainty and singularities in following vehicles due to a lack of effective communication with the preceding vehicle. Furthermore, existing research on vehicle cooperative control contains unreasonable assumptions regarding vehicle spacing. The few spacing strategies that guarantee zero initial spacing error are subject to continuous change due to the expected spacing containing an exponential factor, necessitating constant and unnecessary fine-tuning of the controller. In addition, current research largely neglects the impact of powertrain failures and the requirements for the convergence speed of the controlled error and the need for easily adjustable upper bounds on the convergence time in vehicle cooperative control. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a preset time vehicle cooperation control method based on power drive failure, which can ensure that the position cooperation error converges to a small neighborhood of zero within a preset time, thereby achieving the desired cooperation relationship.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A pre-set time-based vehicle cooperative control method based on power drive failure includes the following steps:

[0007] Step 1: Perform force analysis on the vehicle's motion and, in conjunction with power drive failure, establish a vehicle dynamics model under power drive failure.

[0008] Step 2: Convert the vehicle dynamics and construct the converted vehicle dynamics;

[0009] Step 3: Construct a variable time interval strategy with a lower bound for fault information;

[0010] Step 4: Based on the variable time interval strategy constructed in Step 3, establish the terminal sliding surface;

[0011] Step 5: Based on the terminal sliding surface established in Step 4, design a vehicle cooperation controller to achieve vehicle cooperation control at a preset time.

[0012] Furthermore, the specific process of step 1 is as follows:

[0013] Define the dynamic model of the lead vehicle:

[0014] (1);

[0015] (2);

[0016] (3);

[0017] (4);

[0018] (5);

[0019] in, It refers to the longitudinal position of the lead vehicle. yes The first derivative with respect to time It refers to the lateral position of the lead vehicle. yes The first derivative with respect to time It is the steering angle of the lead vehicle. yes The first derivative with respect to time It is the linear velocity of the lead vehicle. yes The first derivative with respect to time It is the angular velocity of the lead vehicle. yes The first derivative with respect to time It is the linear acceleration of the lead vehicle. It is the angular acceleration of the lead vehicle;

[0020] The convoy has N+1 vehicles, including 1 lead vehicle and N following vehicles, where N is a positive integer greater than or equal to 1, and vehicle i is the i-th following vehicle in the convoy. Force analysis was performed on the vehicle following its motion, and the vehicle dynamics model under power drive failure was established as follows:

[0021] (6);

[0022] (7);

[0023] (8);

[0024] (9);

[0025] (10);

[0026] (11);

[0027] (12);

[0028] in, This is the longitudinal position of vehicle i. yes The first derivative with respect to time This refers to the lateral position of vehicle i. yes The first derivative with respect to time It is the direction angle of vehicle i. yes The first derivative with respect to time It is the linear velocity of vehicle i. yes The first derivative with respect to time It is the angular velocity of vehicle i. yes The first derivative with respect to time It is the linear acceleration of vehicle i. yes The first derivative with respect to time It is the angular acceleration of vehicle i. yes The first derivative with respect to time It is the mass of vehicle i. It is the engine time constant of vehicle i. It is the throttle / brake control input of vehicle i under power drive failure. It is the steering control input for vehicle i under power drive failure.

[0029] (13);

[0030] (14);

[0031] in, It is a failure factor, reflecting the degradation of vehicle driving capability caused by insufficient fuel injection capability. It is an unknown quantity that satisfies the inequality. ,in, It is the lower bound of the known failure factor; This is the throttle / brake control input under fault-free conditions. It is the steering control input under fault-free conditions.

[0032] Furthermore, the specific process of step 2 is as follows:

[0033] The forward point of vehicle i is described as:

[0034] (15);

[0035] (16);

[0036] in, It is the longitudinal position of vehicle i after the transformation. L is the lateral position of vehicle i after the transformation, and L is the straight-line distance between the vehicle's center of gravity and the vehicle's forward position.

[0037] Using the forward points of vehicle i, the vehicle dynamics are transformed, and the transformed vehicle dynamics are constructed as follows:

[0038] (17);

[0039] (18);

[0040] (19);

[0041] (20);

[0042] (twenty one);

[0043] (twenty two);

[0044] in,

[0045] (twenty three);

[0046] (twenty four);

[0047] in, yes The first derivative with respect to time yes The first derivative with respect to time It is the longitudinal velocity of vehicle i after the transformation. yes The first derivative with respect to time It is the lateral velocity of vehicle i after the transformation. yes The first derivative with respect to time It is the longitudinal acceleration of vehicle i after the transformation. yes The first derivative with respect to time It is the lateral acceleration of vehicle i after the transformation. yes The first derivative with respect to time; and It is the control input of the transformed vehicle i, and , The relationship is shown in formulas (23)-(24).

[0048] Similarly, the vehicle dynamics after the lead vehicle transformation are obtained as follows:

[0049] (25);

[0050] (26);

[0051] (27);

[0052] (28);

[0053] in, It is the longitudinal position of the lead vehicle after the transformation. yes The first derivative with respect to time It refers to the lateral position of the lead vehicle after the change. yes The first derivative with respect to time It is the longitudinal speed of the leading vehicle after the change. yes The first derivative with respect to time It is the lateral speed of the lead vehicle after the change. yes The first derivative with respect to time It is the longitudinal acceleration of the lead vehicle after the transformation. It is the lateral acceleration of the lead vehicle after the transformation.

[0054] Furthermore, the specific process of step 3 is as follows:

[0055] The communication topology between vehicles in the convoy is a front-drive-follow type communication topology, which is specifically manifested in that the i-th vehicle behind receives the status information of the (i-1)-th vehicle in front, where i is greater than or equal to 1.

[0056] Based on the predecessor-follower communication topology, a variable time interval strategy with a lower bound for fault information is constructed as follows:

[0057] (29);

[0058] (30);

[0059] (31);

[0060] (32);

[0061] (33);

[0062] (34);

[0063] (35);

[0064] in, It is the longitudinal positional cooperation error of vehicle i. , , , These are all auxiliary items for vehicle i. It is the longitudinal position of the transformed vehicle i-1. It is the longitudinal constant distance between vehicles. It is the lateral positional cooperation error of vehicle i. This refers to the lateral position of the transformed vehicle i-1. It is the lateral constant distance between vehicles. and It is a delay time. and It's the safety factor. It is the absolute value of the expected maximum longitudinal acceleration. It is the absolute value of the expected maximum lateral acceleration. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary term, and t is time.

[0065] Furthermore, the specific process of step 4 is as follows:

[0066] Establish the terminal sliding surface:

[0067] (36);

[0068] (37);

[0069] in,

[0070] (38);

[0071] (39);

[0072] (40);

[0073] (41);

[0074] (42);

[0075] (43);

[0076] in, It is the longitudinal end sliding surface of vehicle i. It is the lateral end sliding surface of vehicle i. yes The first derivative with respect to time yes The first derivative with respect to time and It is an auxiliary item; , These are design parameters that satisfy the inequalities. , ; , It is a preset time parameter that satisfies the inequality , ; and , and It is an auxiliary item; These are design parameters that satisfy the inequalities. .

[0077] Furthermore, the specific process of step 5 is as follows:

[0078] Design a vehicle cooperative controller as follows:

[0079] (44);

[0080] (45);

[0081] in,

[0082] (46);

[0083] (47);

[0084] (48);

[0085] (49);

[0086] (50);

[0087] (51);

[0088] in, , , , , , These are all auxiliary items. It is an auxiliary item The second derivative with respect to time, It is an auxiliary item The first derivative with respect to time It is an auxiliary item The second derivative with respect to time, It is an auxiliary item The first derivative with respect to time; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. .

[0089] The beneficial effects of adopting the above technical solution are as follows: The pre-time vehicle cooperative control method based on power drive failure provided by this invention introduces model transformation, converting the underdriven vehicle model into a fully driven vehicle model, and then performing cooperative control based on longitudinal and lateral vehicle spacing. This avoids the uncertainty and singularity problems of following vehicle trajectories that exist in existing studies that control based on the distance between vehicle centers of gravity and the position angle between vehicles, making it more general and universal for practical applications. Considering the impact of power drive failure, a variable time spacing strategy with a lower bound for failure information is designed. This spacing strategy not only guarantees zero initial spacing error, eliminating the assumption in some studies that requires vehicles in the platoon to meet the desired cooperative relationship at the initial moment, but also avoids the unnecessary losses caused by the continuous change due to the use of exponential factors in a few spacing strategies that can guarantee zero initial spacing error. For convoys with power drive failures in both longitudinal and transverse directions, a preset time sliding mode controller based on model transformation and a variable time interval strategy with a lower bound for fault information was designed. This ensures that the position cooperation error converges to a small neighborhood of zero within a preset time, thus achieving the desired cooperation relationship. At this time, the upper bound of the convergence time is independent of the initial state of the vehicles in the convoy and is only a simple parameter, which greatly reduces the difficulty of setting the upper bound of the convergence time. Attached Figure Description

[0090] Figure 1 A flowchart of a vehicle cooperative control method based on a power drive fault with a preset time provided in an embodiment of the present invention;

[0091] Figure 2 This is a schematic diagram illustrating the relationship between the front point and the center of gravity of a vehicle provided in an embodiment of the present invention;

[0092] Figure 3 This is a diagram showing the longitudinal positional cooperation error results of the second vehicle in a convoy, provided in an embodiment of the present invention.

[0093] Figure 4 This is a diagram showing the lateral positional cooperation error results of the second vehicle in a convoy, provided in an embodiment of the present invention.

[0094] Figure 5This is a diagram showing the longitudinal positional cooperation error results of the third vehicle in a convoy, provided in an embodiment of the present invention.

[0095] Figure 6 The diagram shows the lateral positional cooperation error results of the third vehicle in the convoy, as provided in an embodiment of the present invention. Detailed Implementation

[0096] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0097] like Figure 1 As shown, the method of this embodiment is described below.

[0098] Step 1: Perform force analysis on the vehicle's motion and, in conjunction with power drive failure, establish a vehicle dynamics model under power drive failure. The specific process is as follows:

[0099] Define the dynamic model of the lead vehicle:

[0100] (1);

[0101] (2);

[0102] (3);

[0103] (4);

[0104] (5);

[0105] in, It refers to the longitudinal position of the lead vehicle. yes The first derivative with respect to time It refers to the lateral position of the lead vehicle. yes The first derivative with respect to time It is the steering angle of the lead vehicle. yes The first derivative with respect to time It is the linear velocity of the lead vehicle. yes The first derivative with respect to time It is the angular velocity of the lead vehicle. yes The first derivative with respect to time It is the linear acceleration of the lead vehicle. It is the angular acceleration of the lead vehicle;

[0106] The convoy has N+1 vehicles, including 1 lead vehicle and N following vehicles, where N is a positive integer greater than or equal to 1, and vehicle i is the i-th following vehicle in the convoy. Force analysis was performed on the vehicle following its motion, and the vehicle dynamics model under power drive failure was established as follows:

[0107] (6);

[0108] (7);

[0109] (8);

[0110] (9);

[0111] (10);

[0112] (11);

[0113] (12);

[0114] in, This is the longitudinal position of vehicle i. yes The first derivative with respect to time This refers to the lateral position of vehicle i. yes The first derivative with respect to time It is the direction angle of vehicle i. yes The first derivative with respect to time It is the linear velocity of vehicle i. yes The first derivative with respect to time It is the angular velocity of vehicle i. yes The first derivative with respect to time It is the linear acceleration of vehicle i. yes The first derivative with respect to time It is the angular acceleration of vehicle i. yes The first derivative with respect to time It is the mass of vehicle i. It is the engine time constant of vehicle i. It is the throttle / brake control input of vehicle i under power drive failure. It is the steering control input for vehicle i under power drive failure.

[0115] The specific manifestations of the power drive failure under consideration are as follows:

[0116] (13);

[0117] (14);

[0118] in, It is a failure factor, reflecting the degradation of vehicle driving capability caused by insufficient fuel injection capability. It is an unknown quantity that satisfies the inequality. ,in, It is the lower bound of the known failure factor; This is the throttle / brake control input under fault-free conditions. It is the steering control input under fault-free conditions.

[0119] Step 2: Transform the vehicle dynamics and construct the transformed vehicle dynamics. The specific process is as follows:

[0120] The forward position of vehicle i (e.g.) Figure 2 (As shown) is described as:

[0121] (15);

[0122] (16);

[0123] in, It is the longitudinal position of vehicle i after the transformation. L is the lateral position of vehicle i after the transformation, and L is the straight-line distance between the vehicle's center of gravity and the vehicle's forward position.

[0124] Using the forward points of vehicle i, the vehicle dynamics are transformed, and the transformed vehicle dynamics are constructed as follows:

[0125] (17);

[0126] (18);

[0127] (19);

[0128] (20);

[0129] (twenty one);

[0130] (twenty two);

[0131] in,

[0132] (twenty three);

[0133] (twenty four);

[0134] in, yes The first derivative with respect to time yes The first derivative with respect to time It is the longitudinal velocity of vehicle i after the transformation. yes The first derivative with respect to time It is the lateral velocity of vehicle i after the transformation. yes The first derivative with respect to time It is the longitudinal acceleration of vehicle i after the transformation. yes The first derivative with respect to time It is the lateral acceleration of vehicle i after the transformation. yes The first derivative with respect to time; and It is the control input of the transformed vehicle i, and , The relationship is shown in formulas (23)-(24).

[0135] Similarly, the transformed vehicle dynamics of the leading vehicle are obtained as follows:

[0136] (25);

[0137] (26);

[0138] (27);

[0139] (28);

[0140] in, It is the longitudinal position of the lead vehicle after the transformation. yes The first derivative with respect to time It refers to the lateral position of the lead vehicle after the change. yes The first derivative with respect to time It is the longitudinal speed of the leading vehicle after the change. yes The first derivative with respect to time It is the lateral speed of the lead vehicle after the change. yes The first derivative with respect to time It is the longitudinal acceleration of the lead vehicle after the transformation. It is the lateral acceleration of the lead vehicle after the transformation.

[0141] Step 3: Construct a variable time interval strategy with a lower bound for fault information. The specific process is as follows:

[0142] The communication topology between vehicles in the convoy is a front-drive-follow type communication topology, which is specifically manifested in that the i-th vehicle behind receives the status information of the (i-1)-th vehicle in front, where i is greater than or equal to 1.

[0143] Based on the predecessor-follower communication topology, a variable time interval strategy with a lower bound for fault information is constructed as follows:

[0144] (29);

[0145] (30);

[0146] (31);

[0147] (32);

[0148] (33);

[0149] (34);

[0150] (35);

[0151] in, It is the longitudinal positional cooperation error of vehicle i. , , , These are all auxiliary items for vehicle i. It is the longitudinal position of the transformed vehicle i-1. It is the longitudinal constant distance between vehicles. It is the lateral positional cooperation error of vehicle i. This refers to the lateral position of the transformed vehicle i-1. It is the lateral constant distance between vehicles. and It is a delay time. and It's the safety factor. It is the absolute value of the expected maximum longitudinal acceleration. It is the absolute value of the expected maximum lateral acceleration. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary term, and t is time.

[0152] Step 4: Based on the variable time interval strategy constructed in Step 3, establish the terminal sliding surface. The specific process is as follows:

[0153] Establish the terminal sliding surface:

[0154] (36);

[0155] (37);

[0156] in,

[0157] (38);

[0158] (39);

[0159] (40);

[0160] (41);

[0161] (42);

[0162] (43);

[0163] in, It is the longitudinal end sliding surface of vehicle i. It is the lateral end sliding surface of vehicle i. yes The first derivative with respect to time yes The first derivative with respect to time and It is an auxiliary item; , These are design parameters that satisfy the inequalities. , ; , It is a preset time parameter that satisfies the inequality , ; and , and It is an auxiliary item; These are design parameters that satisfy the inequalities. .

[0164] Step 5: Based on the terminal sliding surface established in Step 4, design a vehicle cooperation controller to achieve vehicle cooperation control at a preset time. The specific process is as follows:

[0165] Design a vehicle cooperative controller as follows:

[0166] (44);

[0167] (45);

[0168] in,

[0169] (46);

[0170] (47);

[0171] (48);

[0172] (49);

[0173] (50);

[0174] (51);

[0175] in, , , , , , These are all auxiliary items. It is an auxiliary item The second derivative with respect to time, It is an auxiliary item The first derivative with respect to time It is an auxiliary item The second derivative with respect to time, It is an auxiliary item The first derivative with respect to time; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. .

[0176] The following demonstrates the stability of the system's actual preset time.

[0177] First, the longitudinal Lyapunov function is designed as follows:

[0178] (52);

[0179] Taking the derivative of the designed longitudinal Lyapunov function (52) with respect to time, we can obtain:

[0180] (53);

[0181] Based on the pre-set time Lyapunov stability theory, the longitudinal terminal sliding surface can be obtained. At the preset time Converges inward to a small neighborhood of zero Inside, among which, auxiliary items for:

[0182] .

[0183] when It converges to a small neighborhood of zero. Within this timeframe, it can be deduced that: at the preset time... Inside, ,in, That is: longitudinal positional cooperation error At the preset time Converges inward to a small neighborhood of zero Inside.

[0184] Similarly, we can obtain: transverse terminal sliding surface At the preset time Converges inward to a small neighborhood of zero Inside, among which, auxiliary items for:

[0185] ;

[0186] This leads to the derivation of the lateral positional cooperation error. At the preset time Converges inward to a small neighborhood of zero Inside, Satisfying inequalities .

[0187] In summary, the stability of the system's actual preset time has been proven.

[0188] This embodiment considers a vehicle convoy consisting of three vehicles, where the first vehicle is the lead vehicle, the second vehicle follows the first vehicle with a desired spacing, and the third vehicle follows the second vehicle with a desired spacing. The vehicle model parameters and parameters related to the desired spacing are selected as follows:

[0189] , , , , , , , , , , ;

[0190] assumed: , ;

[0191] The initial state of the vehicle is defined as follows: =16m, =3.3m, =0 rad, =30m / s, =0 rad / s, =0m / s 2 , =0 rad / s 2 , =1m, =0m, =0 rad, =0m / s, =0 rad / s, =0m / s 2 , =0 rad / s 2 , =-10m, =-4m, =0 rad, =0m / s, =0 rad / s, =0m / s 2=0 rad / s 2 ;

[0192] The acceleration of the lead vehicle is defined as:

[0193] ;

[0194] ;

[0195] The parameters for the vehicle cooperative controller based on the terminal sliding surface are selected as follows: , , , , , , , , , , , .

[0196] Simulation results are as follows Figures 3-6 As shown. Among them, Figure 3 and Figure 4 The longitudinal and lateral positional cooperation errors of the second vehicle in the convoy (i.e., i=1) are given respectively. Figure 5 and Figure 6 The longitudinal and lateral positional cooperation errors of the third vehicle in the convoy (i.e., i=2) are given respectively. It can be easily seen that under the control of the controller designed in this embodiment, the initial values ​​of the vehicle positional cooperation errors are all 0, and they all converge to a small neighborhood of zero within a preset time, thus achieving the desired cooperative motion.

[0197] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope defined by the present invention.

Claims

1. A pre-set time vehicle cooperative control method based on power drive fault, characterized in that: The method includes the following steps: Step 1: Perform force analysis on the vehicle's motion and, in conjunction with power drive failure, establish a vehicle dynamics model under power drive failure. Step 2: Convert the vehicle dynamics and construct the converted vehicle dynamics; Step 3: Construct a variable time interval strategy with a lower bound for fault information; Step 4: Based on the variable time interval strategy constructed in Step 3, establish the terminal sliding surface; the specific process is as follows: Establish the terminal sliding surface: (36)； (37)； in, (38)； (39)； (40)； (41)； (42)； (43)； in, It is the longitudinal end sliding surface of vehicle i. It is the lateral end sliding surface of vehicle i. yes The first derivative with respect to time It is the longitudinal positional cooperation error of vehicle i. yes The first derivative with respect to time It is the lateral positional cooperation error of vehicle i. and It is an auxiliary item; , These are design parameters that satisfy the inequalities. , ; , It is a preset time parameter that satisfies the inequality , ; and , and It is an auxiliary item; These are design parameters that satisfy the inequalities. ; Step 5: Based on the terminal sliding surface established in Step 4, design a vehicle cooperation controller to achieve vehicle cooperation control at a preset time; the specific process is as follows: Design a vehicle cooperative controller as follows: (44)； (45)； in, (46)； (47)； (48)； (49)； (50)； (51)； (30)； (31)； (33)； (34)； (35)； in, , , , , , These are all auxiliary items. It is an auxiliary item The second derivative with respect to time, It is an auxiliary item The first derivative with respect to time It is an auxiliary item The second derivative with respect to time, It is an auxiliary item The first derivative with respect to time; It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary term, where t is time; It is the longitudinal position of vehicle i after the transformation. It is the lateral position of vehicle i after the transformation; It is the longitudinal constant distance between vehicles. It is the constant lateral distance between vehicles; and It is a delay time. and It is the safety factor; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. , It is the lower bound of the known failure factor; These are design parameters that satisfy the inequalities. ; It is the longitudinal velocity of vehicle i after the transformation; It is the lateral velocity of vehicle i after the transformation; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; These are design parameters that satisfy the inequalities. ; It is the absolute value of the expected maximum longitudinal acceleration. It is the absolute value of the expected maximum lateral acceleration; It is the longitudinal acceleration of vehicle i after the transformation. It is the lateral acceleration of vehicle i after the transformation; It is the direction angle of vehicle i. It is the engine time constant of vehicle i.

2. The vehicle cooperative control method based on a preset time for power drive failure according to claim 1, characterized in that: The specific process of step 1 is as follows: Define the dynamic model of the lead vehicle: (1)； (2)； (3)； (4)； (5)； in, It refers to the longitudinal position of the lead vehicle. yes The first derivative with respect to time It refers to the lateral position of the lead vehicle. yes The first derivative with respect to time It is the steering angle of the lead vehicle. yes The first derivative with respect to time It is the linear velocity of the lead vehicle. yes The first derivative with respect to time It is the angular velocity of the lead vehicle. yes The first derivative with respect to time It is the linear acceleration of the lead vehicle. It is the angular acceleration of the lead vehicle; The convoy has N+1 vehicles, including 1 lead vehicle and N following vehicles, where N is a positive integer greater than or equal to 1, and vehicle i is the i-th following vehicle in the convoy. Force analysis was performed on the vehicle following its motion, and the vehicle dynamics model under power drive failure was established as follows: (6)； (7)； (8)； (9)； (10)； (11)； (12)； in, This is the longitudinal position of vehicle i. yes The first derivative with respect to time This refers to the lateral position of vehicle i. yes The first derivative with respect to time It is the direction angle of vehicle i. yes The first derivative with respect to time It is the linear velocity of vehicle i. yes The first derivative with respect to time It is the angular velocity of vehicle i. yes The first derivative with respect to time It is the linear acceleration of vehicle i. yes The first derivative with respect to time It is the angular acceleration of vehicle i. yes The first derivative with respect to time It is the mass of vehicle i. It is the engine time constant of vehicle i. It is the throttle / brake control input of vehicle i under power drive failure. It is the steering control input for vehicle i under power drive failure.

3. The vehicle cooperative control method based on a preset time for a power drive fault according to claim 2, characterized in that: The specific manifestations of the power drive failure are as follows: (13)； (14)； in, It is a failure factor, reflecting the degradation of vehicle driving capability caused by insufficient fuel injection capability. It is an unknown quantity that satisfies the inequality. ,in, It is the lower bound of the known failure factor; This is the throttle / brake control input under fault-free conditions. It is the steering control input under fault-free conditions.

4. The vehicle cooperative control method based on a preset time for a power drive fault according to claim 3, characterized in that: The specific process of step 2 is as follows: The forward point of vehicle i is described as: (15)； (16)； in, It is the longitudinal position of vehicle i after the transformation. L is the lateral position of vehicle i after the transformation, and L is the straight-line distance between the vehicle's center of gravity and the vehicle's forward position. Using the preceding points of vehicle i, the vehicle dynamics are transformed, and the transformed vehicle dynamics are constructed as follows: (17)； (18)； (19)； (20)； (21)； (22)； in, (23)； (24)； in, yes The first derivative with respect to time yes The first derivative with respect to time It is the longitudinal velocity of vehicle i after the transformation. yes The first derivative with respect to time It is the lateral velocity of vehicle i after the transformation. yes The first derivative with respect to time It is the longitudinal acceleration of vehicle i after the transformation. yes The first derivative with respect to time It is the lateral acceleration of vehicle i after the transformation. yes The first derivative with respect to time; and It is the control input of the transformed vehicle i, and , The relationship is shown in formulas (23)-(24); Similarly, the vehicle dynamics after the lead vehicle transformation are obtained as follows: (25)； (26)； (27)； (28)； in, It is the longitudinal position of the lead vehicle after the transformation. yes The first derivative with respect to time It refers to the lateral position of the lead vehicle after the change. yes The first derivative with respect to time It is the longitudinal speed of the leading vehicle after the change. yes The first derivative with respect to time It is the lateral speed of the lead vehicle after the change. yes The first derivative with respect to time It is the longitudinal acceleration of the lead vehicle after the transformation. It is the lateral acceleration of the lead vehicle after the transformation.

5. The vehicle cooperative control method based on a preset time for a power drive fault according to claim 4, characterized in that: The specific process of step 3 is as follows: The communication topology between vehicles in the convoy is a front-drive-follow type communication topology, which is specifically manifested in that the i-th vehicle behind receives the status information of the (i-1)-th vehicle in front, where i is greater than or equal to 1. Based on the predecessor-follower communication topology, a variable time interval strategy with a lower bound for fault information is constructed as follows: (29)； (30)； (31)； (32)； (33)； (34)； (35)； in, It is the longitudinal positional cooperation error of vehicle i. , , , These are all auxiliary items for vehicle i. It is the longitudinal position of the transformed vehicle i-1. It is the longitudinal constant distance between vehicles. It is the lateral positional cooperation error of vehicle i. This refers to the lateral position of the transformed vehicle i-1. It is the lateral constant distance between vehicles. and It is a delay time. and It's the safety factor. It is the absolute value of the expected maximum longitudinal acceleration. It is the absolute value of the expected maximum lateral acceleration. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary item for vehicle i The value at an initial time of zero. It is an auxiliary item for vehicle i The value of the first derivative at initial time zero. It is an auxiliary item for vehicle i The value of the second derivative at initial time zero. It is an auxiliary term, and t is time.

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