A steering control method and device for a four-wheel independent drive off-road platform

Abstract

The present application discloses a steering control method and device for a four-wheel independent drive off-road platform, which is applied to off-road vehicles. The steering angle and speed range of the off-road vehicle are judged, and the torque of the wheel is adjusted by different control methods to obtain different wheel adjustment speeds. The wheel target speeds in different speed ranges are calculated by different calculation methods, and the wheel adjustment speed is compared with the wheel target speed. When the wheel adjustment speed is equal to the wheel target speed, the torque adjustment is stopped. This scheme comprehensively analyzes and judges the wheel adjustment speed obtained by torque adjustment and the calculated wheel target speed from multiple aspects to obtain the timing to stop adjusting the wheel torque, which can realize stable and efficient steering of the off-road vehicle and effectively improve the maneuverability, stability and safety of the off-road vehicle.

Description

Technical Field

[0001] The present application relates to the field of off-road vehicle steering control, and in particular to a steering control method and a device for a four-wheel independent drive off-road platform. Background Art

[0002] In the four-wheel independent drive of off-road vehicles, four motors are connected to four wheels respectively, and each wheel corresponds to a controller. Each wheel can provide power continuously, with strong off-road capability and good redundancy. However, since the four-wheel independent drive controls each wheel individually, how to control the four-wheel independent drive smoothly becomes the key to practical application.

[0003] Therefore, how to improve the stability of four-wheel independent drive is a technical problem that needs to be solved urgently. Summary of the invention

[0004] The embodiment of the present application discloses a steering control method for a four-wheel independent drive off-road platform, which is used to improve the stability of the four-wheel independent drive.

[0005] In order to solve the above technical problems,

[0006] In the first aspect, this application provides the following technical solutions:

[0007] A four-wheel independent drive off-road platform steering control method is applied to an off-road vehicle, the off-road vehicle comprises wheels, the wheels comprise inner wheels and outer wheels;

[0008] Obtaining the speed and steering angle of the off-road vehicle;

[0009] When the steering angle is not zero, determining the speed interval in which the speed is located, the speed interval includes a low speed interval, a medium speed interval and a high speed interval;

[0010] When the speed is in the low speed range, adjusting the torque of the wheel according to a first control method, the first control method is to increase the torque of the outer wheel to obtain a first adjusted speed of the outer wheel; and calculating a first target speed of the outer wheel according to a first calculation method, the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel, and when the first adjusted speed of the outer wheel is equal to the first target speed of the outer wheel, stopping increasing the torque of the outer wheel;

[0011] When the speed is in the medium speed range, adjusting the torque of the wheel according to a second control method, the second control method is to reduce the torque of the inner wheel and increase the torque of the outer wheel to obtain a second adjusted speed of the wheel; and calculating a second target speed of the wheel according to a second calculation method, the second calculation method is to calculate the second target speed of the wheel according to the speed of the off-road vehicle; when the second adjusted speed of the wheel is equal to the second target speed of the wheel, stopping reducing the torque of the inner wheel and stopping increasing the torque of the outer wheel;

[0012] When the speed is in the high-speed range, the torque of the wheel is adjusted according to a third control method, the third control method is to reduce the torque of the inner wheel to obtain a third adjusted speed of the inner wheel; and the third target speed of the inner wheel is calculated according to a third calculation method, the third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel; when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, stop reducing the torque of the inner wheel.

[0013] In some embodiments, when the off-road vehicle is turning left, the inner wheels include a left front wheel and a left rear wheel, the outer wheels include a right front wheel and a right rear wheel, and the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are independently controlled; the running speeds of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are obtained, which are V 1y 、V 2y 、V 3y and V 4y , V 1y is the speed of the left front wheel, V 2y is the speed of the left rear wheel, V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel; according to the running speeds of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel, the speed V of the off-road vehicle is obtained h , the speed V h The calculation formula is:

[0014] Where: V h is the speed of the off-road vehicle, V 2y is the speed of the left rear wheel, V 3y is the speed of the right rear wheel.

[0015] In some embodiments, when V h ≤25km, the speed interval of the off-road vehicle is in the low speed interval; when 25km / h<V h≤60km / h, the speed interval of the off-road vehicle is in the medium speed interval; when V h >60km / h, the speed range of the speed of the off-road vehicle is in the high speed range.

[0016] In some embodiments, a first target speed of the right front wheel and a first target speed of the right rear wheel are calculated; the first target speed of the right rear wheel is calculated based on the running speed of the left rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; the first target speed of the right front wheel is calculated based on the running speed of the left front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle.

[0017] In some embodiments, the calculation formulas for the first target speed of the right front wheel and the first target speed of the right rear wheel are:

[0018] Where V3 refers to the first target speed of the right rear wheel, V4 refers to the first target speed of the right front wheel, and V 1y is the running speed of the left front wheel, V 2y is the running speed of the left rear wheel, L The wheelbase of the off-road vehicle; B is the wheelbase of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0019] In some embodiments, the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are calculated; the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are calculated based on the speed of the off-road vehicle, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle.

[0020] In some embodiments, the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are calculated as follows:

[0021] Where V1 refers to the second target speed of the left front wheel, V2 refers to the second target speed of the left rear wheel, V3 refers to the second target speed of the right rear wheel, V4 refers to the second target speed of the right front wheel, and V h is the speed of the off-road vehicle, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0022] In some embodiments, a third target speed of the left front wheel and a third target speed of the left rear wheel are calculated; the third target speed of the left front wheel is calculated based on the running speed of the right front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; the third target speed of the left rear wheel is calculated based on the running speed of the right rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle.

[0023] In some embodiments, the third target speed of the left front wheel and the third target speed of the left rear wheel are calculated as follows:

[0024] Where, V1 is the third target speed of the left front wheel; V2 is the third target speed of the left rear wheel; V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0025] In the second aspect, this application provides the following technical solutions:

[0026] A four-wheel independent drive off-road platform steering control device, applied to off-road vehicles:

[0027] The off-road vehicle comprises inner wheels and outer wheels. When the off-road vehicle turns left, the inner wheels comprise a left front wheel and a left rear wheel, the outer wheels comprise a right front wheel and a right rear wheel, and the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are independently controlled.

[0028] Four driving mechanisms are respectively connected to the left front wheel, the left rear wheel, the right front wheel and the right rear wheel;

[0029] Four controllers are connected to the four driving mechanisms respectively, and the four controllers control the four driving mechanisms respectively;

[0030] A master controller connected to the four controllers to control the four controllers;

[0031] The master controller also includes:

[0032] An acquisition module, used for acquiring the speed and steering angle of the off-road vehicle;

[0033] A first judgment module, used for judging the speed interval of the speed when the steering angle is not zero, the speed interval including a low speed interval, a medium speed interval and a high speed interval;

[0034] a first control module, configured to adjust the torque of the wheel according to a first control method when the speed is in a low speed range, wherein the first control method is to increase the torque of the outer wheel to obtain a first adjusted speed of the outer wheel;

[0035] a first calculation module, configured to calculate a first target speed of the wheel according to a first calculation method when the speed is in a low speed range; the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel;

[0036] a first judgment submodule, configured to stop increasing the torque of the outer wheel when the first adjustment speed of the outer wheel is equal to the first target speed of the outer wheel;

[0037] a second control module, configured to adjust the torque of the wheel according to a second control method when the speed is in a medium speed range, wherein the second control method is to reduce the torque of the inner wheel and increase the torque of the outer wheel to obtain a second adjusted speed of the wheel;

[0038] a second calculation module, configured to calculate a second target speed of the wheel according to a second calculation method when the speed is in a medium speed range, wherein the second calculation method is to calculate the second target speed of the wheel according to the speed of the off-road vehicle;

[0039] a second judgment submodule, configured to stop reducing the torque of the inner wheel and stop increasing the torque of the outer wheel when the second adjustment speed of the wheel is equal to the second target speed of the wheel;

[0040] a third control module, configured to adjust the torque of the wheel according to a third control method when the speed is in a high speed range, wherein the third control method is to reduce the torque of the inner wheel to obtain a third adjusted speed of the inner wheel;

[0041] a third calculation module, configured to calculate a third target speed of the inner wheel according to a third calculation method when the speed is in a high speed range, wherein the third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel;

[0042] The third judgment submodule is configured to stop reducing the torque of the inner wheel when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel.

[0043] In an embodiment of the present application, by acquiring the speed and steering angle of the off-road vehicle, when the steering angle is not zero, the speed range of the speed is further determined. When the speed is in the low speed range, the torque of the outer wheel is increased according to the first control method to obtain a first adjusted speed of the outer wheel; and the first target speed of the outer wheel is calculated according to the first calculation method. When the first adjusted speed of the outer wheel is equal to the first target speed of the outer wheel, the torque of the outer wheel is stopped from being increased; when the speed is in the medium speed range, the torque of the inner wheel is reduced according to the second control method, and the torque of the outer wheel is increased to obtain a second adjusted speed of the wheel; and the second target speed of the wheel is calculated according to the second calculation method. When the second adjusted speed of the wheel is equal to the second target speed of the wheel, the torque of the inner wheel is stopped from being reduced, and the torque of the outer wheel is stopped from being increased; when the speed is in the high speed range, the torque of the inner wheel is reduced according to the third control method to obtain a third adjusted speed of the inner wheel; and the third target speed of the inner wheel is calculated according to the third calculation method. When the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, the torque of the inner wheel is stopped from being reduced.

[0044] In this solution, the steering angle and the speed range are judged, and then the wheel torque is adjusted through different control methods to obtain different wheel adjustment speeds, and the target speed of the wheel in different speed ranges is calculated through different calculation methods, and then the target speed of the wheel is compared with the wheel adjustment speed. When the wheel adjustment speed is equal to the wheel target speed, the torque adjustment is stopped. This solution obtains the wheel adjustment speed and the calculated wheel target speed through torque adjustment, and obtains the timing to stop the torque adjustment, which can realize stable and efficient steering of off-road vehicles and effectively improve the maneuverability, stability and safety of off-road vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0046] Figure 1 It is a schematic diagram of a four-wheel independent drive off-road platform disclosed in an embodiment of the present application.

[0047] Figure 2 It is a structural schematic diagram of a four-wheel independent drive off-road platform disclosed in an embodiment of the present application.

[0048] Figure 3 It is a schematic diagram of the relationship between the body size, speed and turning angle of a four-wheel independent drive off-road platform disclosed in an embodiment of the present application.

[0049] Figure 4 It is a flow chart of a four-wheel independent drive off-road platform disclosed in an embodiment of the present application. DETAILED DESCRIPTION

[0050] The present invention is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Each aspect so defined can be combined with any other aspect or aspects, unless explicitly stated not to be combined. In particular, any feature that is considered to be preferred or advantageous can be combined with one or more other features that are considered to be preferred or advantageous.

[0051] The terms "first", "second" and the like appearing in the present invention are only for the convenience of description to distinguish different components with the same name, and do not indicate a priority or primary and secondary relationship.

[0052] In addition, when an element is referred to as being "on" another element, the element may be directly on the other element, or may be indirectly on the other element with one or more intermediate elements interposed therebetween. In addition, when an element is referred to as being "connected to" another element, the element may be directly connected to the other element, or may be indirectly connected to the other element with one or more intermediate elements interposed therebetween. Hereinafter, the same reference numerals represent the same elements.

[0053] In the present invention, descriptions of directions or positional relationships indicated by “upper”, “lower”, “top”, “bottom”, “front”, “back”, “inside” and “outside” are used only to facilitate the description of the present invention, and do not indicate or imply that the device referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, it should not be understood as limiting the scope of protection of the present invention.

[0054] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0055] The embodiment of the present application discloses a steering control method and device for a four-wheel independent drive off-road platform, which is used to independently drive the four wheels of an off-road vehicle.

[0056] Embodiment 1

[0057] See also Figure 1 , Figure 1This is a steering control method for a four-wheel independent drive off-road platform disclosed in an embodiment of the present application. Figure 1 As shown, the steering control method of the four-wheel independent drive off-road platform includes the following steps.

[0058] In step S110, the speed and steering angle of the off-road vehicle are obtained.

[0059] Furthermore, the off-road vehicle includes wheels, which include inner wheels and outer wheels. When the off-road vehicle turns left, the inner wheels include a left front wheel and a left rear wheel, and the outer wheels include a right front wheel and a right rear wheel. The left front wheel, left rear wheel, right front wheel and right rear wheel are independently controlled.

[0060] Get the running speeds of the left front wheel, left rear wheel, right front wheel and right rear wheel, which are V 1y 、V 2y 、V 3y and V 1y ; V 1y is the speed of the left front wheel, V 2y is the speed of the left rear wheel, V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel;

[0061] According to the running speeds of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel, the speed V of the off-road vehicle is obtained. h , the speed V h The calculation formula is:

[0062] Where: V h is the speed of the off-road vehicle, V 2y is the speed of the left rear wheel, V 3y is the speed of the right rear wheel.

[0063] It can be understood that in this example, the speed V of the off-road vehicle h The running speed V of the left rear wheel 2y and right rear wheel V 3y The running speed of the left rear wheel is V 2y and right rear wheel V 3y The running speed of the four wheels can be obtained by a speed sensor, that is, the running speed of the four wheels can be calculated by the speed sensor of the motor itself and the reduction ratio, etc. This is not specifically limited in this embodiment.

[0064] It can be understood that the left front wheel, left rear wheel, right front wheel and right rear wheel in this embodiment can be independently controlled.

[0065] In this embodiment, the steering angle α of the off-road vehicle can be detected by a sensor, such as an angle sensor, which is not specifically limited in this embodiment.

[0066] In this embodiment, the distance between the axles of the front wheels and the rear wheels is the wheelbase. L , that is, the distance between the axle centers of the left front wheel and the left rear wheel is the wheelbase L , or the distance between the axle centers of the right front wheel and the right rear wheel is the wheelbase L .

[0067] In this embodiment, the distance between the axles of the front wheels or the rear wheels is the wheelbase. B , that is, the distance between the axles of the left front wheel and the right front wheel is the wheelbase B , or the distance between the axles of the left rear wheel and the right rear wheel is the wheelbase B .

[0068] In step S120, when the steering angle is not zero, the speed range of the speed is determined, and the speed range includes a low speed range, a medium speed range and a high speed range.

[0069] Furthermore, when V h ≤25km, the speed interval of the off-road vehicle is in the low speed interval; when 25km / h<V h ≤60km / h, the speed interval of the off-road vehicle is in the medium speed interval; when V h >60km / h, the speed range of the speed of the off-road vehicle is in the high speed range.

[0070] In this embodiment, when the steering angle of the off-road vehicle is not zero, the speed range of the off-road vehicle is further determined, and the speed of the off-road vehicle is divided into three different ranges: low speed, medium speed, and high speed. Different ranges have different control methods.

[0071] It can be understood that when the steering angle of the wheel is zero, the vehicle travels in a straight line and there is no need to judge the speed range.

[0072] In step S130, when the speed is in the low speed range, the torque of the wheel is adjusted according to a first control method, the first control method is to increase the torque of the outer wheel to obtain a first adjusted speed of the outer wheel; and the first target speed of the outer wheel is calculated according to a first calculation method, the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel, and when the first adjusted speed of the outer wheel is equal to the first target speed of the outer wheel, stop increasing the torque of the outer wheel.

[0073] In this embodiment, when the speed is in a low speed range, the torque of the wheel is adjusted according to a first control method to obtain a first adjusted speed of the wheel; and the first target speed of the wheel is calculated according to a first calculation method. When the first adjusted speed of the wheel is equal to the first target speed, the torque adjustment is stopped.

[0074] It can be understood that the first control method is to increase the torque of the outer wheel, and the first adjustment speed of the outer wheel is obtained by increasing the torque of the outer wheel.

[0075] It can be understood that, taking the off-road vehicle turning left as an example, the outer wheels of the off-road vehicle are the right front wheel and the right rear wheel, and the inner wheels are the left front wheel and the left rear wheel. By increasing the torque of the outer wheels, that is, increasing the torque of the right front wheel and the right rear wheel, the first adjustment speed of the right front wheel and the first adjustment speed of the right rear wheel are obtained.

[0076] It can be understood that the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel.

[0077] Further, a first target speed of the right front wheel and a first target speed of the right rear wheel are calculated.

[0078] The first target speed of the right rear wheel is calculated according to the running speed of the left rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle;

[0079] The first target speed of the right front wheel is calculated according to the running speed of the left front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle.

[0080] Furthermore, the calculation formulas for the first target speed of the right front wheel and the first target speed of the right rear wheel are:

[0081] Where V3 refers to the first target speed of the right rear wheel, V4 refers to the first target speed of the right front wheel, and V 1y is the running speed of the left front wheel, V 2y is the running speed of the left rear wheel, L is the wheelbase of the off-road vehicle; B is the track of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0082] It can be understood that when the speed is in the low speed range, the target speed of the outer wheel is calculated by the running speed, wheelbase, track and steering angle of the inner wheel, so as to maintain the steering balance of the off-road vehicle and achieve smooth control of the steering control of the four-wheel independent drive off-road platform.

[0083] When the first adjustment speed of the right front wheel is equal to the first target speed of the right front wheel, and the first adjustment speed of the right rear wheel is equal to the first target speed of the right rear wheel, the adjustment of the torque is stopped. It can be understood that when the adjustment speed of one of the right front wheel and the right rear wheel is equal to the target speed of the wheel, the adjustment of the torque is stopped. In this way, the technical effect of independent control of each wheel is achieved.

[0084] In step S140, when the speed is in the medium speed range, the torque of the wheel is adjusted according to a second control method, the second control method is to reduce the torque of the inner wheel and increase the torque of the outer wheel to obtain a second adjusted speed of the wheel; and the second target speed of the wheel is calculated according to a second calculation method, the second calculation method is to calculate the second target speed of the wheel according to the speed of the off-road vehicle; when the second adjusted speed of the wheel is equal to the second target speed of the wheel, stop reducing the torque of the inner wheel and stop increasing the torque of the outer wheel.

[0085] In this embodiment, when the speed is in the medium speed range, the torque of the wheel is adjusted according to the second control method to obtain the second adjusted speed of the wheel; and the second target speed of the wheel is calculated according to the second calculation method. When the second adjusted speed of the wheel is equal to the second target speed, the torque adjustment is stopped.

[0086] It can be understood that the second control method adjusts the torque of the wheels to reduce the torque of the inner wheel and increase the torque of the outer wheel. The adjusted speed of each wheel is obtained by adjusting the torque.

[0087] It can be understood that, taking the off-road vehicle turning left as an example, the inner wheels are the left front wheel and the left rear wheel, and the outer wheels are the right front wheel and the right rear wheel. When the speed is in the medium speed range, it is necessary to reduce the torque of the inner wheel (i.e. reduce the torque of the left front wheel and the left rear wheel), and increase the torque of the outer wheel (i.e. increase the torque of the right front wheel and the right rear wheel). By adjusting the torque of the inner wheel and the outer wheel, the second adjusted speed of the left front wheel, the second adjusted speed of the left rear wheel, the second adjusted speed of the right front wheel and the second adjusted speed of the right rear wheel are obtained.

[0088] It can be understood that the second calculation method is to calculate the second target speed of the wheels according to the speed of the off-road vehicle, that is, to calculate the second target speeds of the inner wheels and the outer wheels, that is, the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel.

[0089] Further, calculating a second target speed of the left front wheel, a second target speed of the left rear wheel, a second target speed of the right front wheel, and a second target speed of the right rear wheel;

[0090] The second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are calculated based on the speed of the off-road vehicle, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle.

[0091] Furthermore, the calculation formulas for the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are:

[0092] Where V1 refers to the second target speed of the left front wheel, V2 refers to the second target speed of the left rear wheel, V3 refers to the second target speed of the right rear wheel, V4 refers to the second target speed of the right front wheel, and V h is the speed of the off-road vehicle, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0093] It can be understood that when the speed of the off-road vehicle is in the medium speed range, the target speed of each wheel is calculated based on the speed of the off-road vehicle.

[0094] When the second adjustment speed of the left front wheel is equal to the second target speed of the left front wheel, the second adjustment speed of the left rear wheel is equal to the second target speed of the left rear wheel, the second adjustment speed of the right front wheel is equal to the second target speed of the right front wheel, and the second adjustment speed of the right rear wheel is equal to the second target speed of the right rear wheel, the adjustment of the torque is stopped. It can be understood that when the adjustment speed of one of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel is equal to the target speed of the wheel, the adjustment of the torque is stopped. In this way, the technical effect of independent control of each wheel is achieved.

[0095] When the speed of the off-road vehicle is in a medium speed range, when the off-road vehicle turns, the inner and outer sides of the off-road vehicle can be turned evenly, that is, both the inner wheels and the outer wheels can be turned.

[0096] In step S150, when the speed is in the high speed range, the torque of the wheel is adjusted according to a third control method, the third control method is to reduce the torque of the inner wheel to obtain a third adjusted speed of the inner wheel; and the third target speed of the inner wheel is calculated according to a third calculation method, the third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel; when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, stop reducing the torque of the inner wheel.

[0097] In this embodiment, when the speed is in the high-speed range, the torque of the wheel is adjusted according to the third control method to obtain the third adjusted speed of the wheel; and the third target speed of the wheel is calculated according to the third calculation method. When the third adjusted speed of the wheel is equal to the third target speed, the adjustment of the torque is stopped.

[0098] It can be understood that the third control method adjusts the torque of the wheel by reducing the torque of the inner wheel, and the adjusted speed of the inner wheel is obtained by reducing the torque of the inner wheel.

[0099] It can be understood that, taking the off-road vehicle turning left as an example, the inner wheels are the left front wheel and the left rear wheel, and the outer wheels are the right front wheel and the right rear wheel. When the speed is in the high speed range, only the torque of the inner wheels is reduced (i.e., the torque of the left front wheel and the left rear wheel is reduced), and the torque of the outer wheels is not adjusted, and the adjusted speed of the inner wheels is obtained, that is, the third adjusted speed of the left front wheel and the third adjusted speed of the left rear wheel are obtained.

[0100] It can be understood that the third calculation method is to calculate the third target speed of the inner wheels according to the running speed of the outer wheels, that is, to calculate the third target speed of the left front wheel and the third target speed of the left rear wheel.

[0101] Further, a third target speed of the left front wheel and a third target speed of the left rear wheel are calculated; the third target speed of the left front wheel is calculated according to the running speed of the right front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle;

[0102] The third target speed of the left rear wheel is calculated according to the running speed of the right rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle.

[0103] Furthermore, the third target speed of the left front wheel and the third target speed of the left rear wheel are calculated as follows:

[0104] Where, V1 is the third target speed of the left front wheel; V2 is the third target speed of the left rear wheel; V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0105] When the third adjusted speed of the left front wheel is equal to the third target speed of the left front wheel, and the third adjusted speed of the left rear wheel is equal to the third target speed of the left rear wheel, the adjustment of the torque is stopped. It can be understood that when the adjusted speed of one of the left front wheel and the left rear wheel is equal to the target speed of the wheel, the adjustment of the torque is stopped. In this way, the technical effect of independent control of each wheel is achieved.

[0106] When the speed of the off-road vehicle is in a high-speed range, the off-road vehicle can achieve stable steering at a high speed, preventing the off-road vehicle from rolling over when turning at a high speed.

[0107] It can be understood that the above embodiment is illustrated by an off-road vehicle turning left. When the off-road vehicle turns left, the steering angle α is a positive value; when the off-road vehicle turns right, the steering angle α is a negative value; in the target speed calculation method, the above α is replaced by -a, and the various target speeds when the off-road vehicle turns right can be calculated.

[0108] It can be understood that in the embodiments of the present application, the first control method, the second control method and the third control method are different, that is, the torque adjustment method is different in different speed ranges; the first calculation method, the second calculation method and the third calculation method are different, that is, the target speed is calculated differently in different speed ranges.

[0109] In one embodiment, when the steering angle of the off-road vehicle is zero, the off-road vehicle travels in a straight line, and the torque of each wheel is controlled in a default manner, and the torque of each wheel is equal.

[0110] In one embodiment, the angle β of the off-road vehicle's pedal is also obtained, 0≤β≤1, wherein when β=0, it represents that the off-road vehicle's power output is 0%, and the total torque of the off-road vehicle is minimum; when β=1, it represents that the off-road vehicle's power output is 100%, and the total torque of the off-road vehicle is maximum.

[0111] It can be understood that the total torque of the off-road vehicle is linearly related to the angle of the pedal. The sum of the torques of each wheel is the total torque of the off-road vehicle.

[0112] In summary, in the present application, by acquiring the speed and steering angle of the off-road vehicle, when the steering angle is not zero, the speed range of the speed is further determined, and when the speed is in the low speed range, the torque of the outer wheel is increased according to the first control method to obtain the first adjusted speed of the outer wheel; and the first target speed of the outer wheel is calculated according to the first calculation method, and when the first adjusted speed of the outer wheel is equal to the first target speed of the outer wheel, the torque of the outer wheel is stopped from being increased; when the speed is in the medium speed range, the torque of the inner wheel is reduced according to the second control method, and the torque of the outer wheel is increased to obtain the second adjusted speed of the wheel; and the second target speed of the wheel is calculated according to the second calculation method, and when the second adjusted speed of the wheel is equal to the second target speed of the wheel, the torque of the inner wheel is stopped from being reduced, and the torque of the outer wheel is stopped from being increased; when the speed is in the high speed range, the torque of the inner wheel is reduced according to the third control method to obtain the third adjusted speed of the inner wheel; and the third target speed of the inner wheel is calculated according to the third calculation method, and when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, the torque of the inner wheel is stopped from being reduced.

[0113] In this solution, the torque of the wheel is adjusted by different control methods through the judgment of the speed range of the steering angle and speed, and different adjustment speeds of the wheel are obtained. The target speed of the wheel in different speed ranges is calculated by different calculation methods, and then the target speed of the wheel is compared with the adjustment speed of the wheel. When the adjustment speed of the wheel is equal to the target speed of the wheel, the adjustment of the torque is stopped. This solution comprehensively analyzes and judges the adjustment speed and the calculated target speed of the wheel from the steering angle, speed, and torque adjustment, and obtains the timing to stop the torque adjustment, which can realize stable and efficient steering of the off-road vehicle and effectively improve the maneuverability, stability and safety of the off-road vehicle.

[0114] Embodiment 2

[0115] like Figure 2 As shown, the embodiment of the present application provides a four-wheel independent drive off-road platform steering control device, which is applied to off-road vehicles;

[0116] The off-road vehicle comprises inner wheels and outer wheels. When the off-road vehicle turns left, the inner wheels comprise a left front wheel and a left rear wheel, the outer wheels comprise a right front wheel and a right rear wheel, and the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are independently controlled.

[0117] Four driving mechanisms are respectively connected to the left front wheel, the left rear wheel, the right front wheel and the right rear wheel;

[0118] Four controllers are connected to the four driving mechanisms respectively, and the four controllers control the four driving mechanisms respectively;

[0119] A master controller connected to the four controllers to control the four controllers;

[0120] The master controller also includes:

[0121] An acquisition module, used for acquiring the speed and steering angle of the off-road vehicle;

[0122] A first judgment module, used for judging the speed interval of the speed when the steering angle is not zero, the speed interval including a low speed interval, a medium speed interval and a high speed interval;

[0123] a first control module, configured to adjust the torque of the wheel according to a first control method when the speed is in a low speed range, wherein the first control method is to increase the torque of the outer wheel to obtain a first adjusted speed of the outer wheel;

[0124] a first calculation module, configured to calculate a first target speed of the wheel according to a first calculation method when the speed is in a low speed range; the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel;

[0125] a first judgment submodule, configured to stop increasing the torque of the outer wheel when the first adjustment speed of the outer wheel is equal to the first target speed of the outer wheel;

[0126] a second control module, configured to adjust the torque of the wheel according to a second control method when the speed is in a medium speed range, wherein the second control method is to reduce the torque of the inner wheel and increase the torque of the outer wheel to obtain a second adjusted speed of the wheel;

[0127] a second calculation module, configured to calculate a second target speed of the wheel according to a second calculation method when the speed is in a medium speed range, wherein the second calculation method is to calculate the second target speed of the wheel according to the speed of the off-road vehicle;

[0128] a second judgment submodule, configured to stop reducing the torque of the inner wheel and stop increasing the torque of the outer wheel when the second adjustment speed of the wheel is equal to the second target speed of the wheel;

[0129] a third control module, configured to adjust the torque of the wheel according to a third control method when the speed is in a high speed range, wherein the third control method is to reduce the torque of the inner wheel to obtain a third adjusted speed of the inner wheel;

[0130] a third calculation module, configured to calculate a third target speed of the inner wheel according to a third calculation method when the speed is in a high speed range, wherein the third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel;

[0131] The third judgment submodule is configured to stop reducing the torque of the inner wheel when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel.

[0132] Furthermore, the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are a left front wheel 11 located at the left front of the off-road vehicle, a left rear wheel 12 located at the left rear of the off-road vehicle, a right rear wheel 13 located at the right rear of the off-road vehicle and a right front wheel 14 located at the right front of the off-road vehicle; the four driving mechanisms include a first driving mechanism 21 drivingly connected to the left front wheel 11, a second driving mechanism 22 drivingly connected to the left rear wheel 12, a third driving mechanism 23 drivingly connected to the right rear wheel 13 and a fourth driving mechanism 24 drivingly connected to the right front wheel 14; the four controllers include a first controller 31 connected to the first driving mechanism 21, a second controller 32 connected to the second driving mechanism 22, a third controller 33 connected to the third driving mechanism 23 and a fourth controller 34 connected to the fourth driving mechanism 24, and the off-road vehicle also includes an integrated controller 4, which is connected to the first controller 31, the second controller 32, the third controller 33 and the fourth controller 34 to control the first controller 31, the second controller 32, the third controller 33 and the fourth controller 34.

[0133] The off-road vehicle further includes a reducer 6, the output end of the driving mechanism is connected to the input end of the reducer 6, the output end of the reducer 6 is connected to a half shaft 7, and the half shaft 7 is connected to the wheel through a constant velocity universal joint 8. The driving mechanism drives the reducer 6 to operate, and the reducer 6 is connected to the wheel through the half shaft 7 and the constant velocity universal joint 8, so that the driving mechanism drives the wheel to rotate. The reducer 6 can lengthen the half shaft 7, so that the length of the off-road vehicle suspension is larger.

[0134] The off-road vehicle also includes a power battery 5, which is used to provide electrical energy for the vehicle. The power battery 5 is connected to a master controller 4, and the master controller 4 controls four controllers via a CAN line (controller area network bus) to achieve four-wheel independent drive.

[0135] The master controller 4 has different control modes according to the steering angle and running speed of the off-road vehicle. When the steering angle of the off-road vehicle is not zero, the speed range of the speed is further determined, and the speed range includes a low speed range, a medium speed range and a high speed range. When the speed is in the low speed range, the torque of the outer wheel is increased according to the first control method to obtain a first adjustment speed of the outer wheel; and the first target speed of the outer wheel is calculated according to the first calculation method. When the first adjustment speed of the outer wheel is equal to the first target speed of the outer wheel, the increase of the torque of the outer wheel is stopped; when the speed is in the medium speed range, the torque of the inner wheel is reduced according to the second control method, and the torque of the outer wheel is increased to obtain a second adjustment speed of the wheel; and the second target speed of the wheel is calculated according to the second calculation method. When the second adjustment speed of the wheel is equal to the second target speed of the wheel, the reduction of the torque of the inner wheel is stopped, and the increase of the torque of the outer wheel is stopped; when the speed is in the high speed range, the torque of the inner wheel is reduced according to the third control method to obtain a third adjustment speed of the inner wheel; and the third target speed of the inner wheel is calculated according to the third calculation method. When the third adjustment speed of the inner wheel is equal to the third target speed of the inner wheel, the reduction of the torque of the inner wheel is stopped.

[0136] It can be understood that in the embodiment of the present application, the first control mode, the second control mode and the third control mode are different, that is, in different speed ranges, the torque adjustment mode is different; the first calculation mode, the second calculation mode and the third calculation mode are different, that is, in different speed ranges, the target speed calculation mode is different. In different speed ranges, the adjustment speed of the wheel is obtained according to different control modes, and the target speed of the wheel is obtained according to different calculation modes. When the adjustment speed of the wheel is equal to the target speed of the wheel, the torque adjustment is stopped.

[0137] It can be understood that in different speed ranges, when the adjustment speed of one wheel is equal to the target speed of the wheel, the torque adjustment of the wheel is stopped, instead of waiting until the adjustment speeds of all wheels are equal to the target speed, so as to achieve the technical effect of four-wheel independent drive and stable operation.

[0138] The four-wheel independent drive off-road platform steering control device in this example is applied to off-road vehicles, including four wheels, four driving mechanisms, four controllers and a master controller; the four driving mechanisms are respectively connected to the four wheel driving connections, and the four wheels are driven independently; the four controllers are respectively connected to the four driving mechanisms, and the four controllers control the four driving mechanisms respectively; the master controller is connected to the four controllers to control the four controllers, and the master controller obtains the speed and steering angle of the off-road vehicle, and further determines the speed range when the steering angle is not zero. When the speed is in the low-speed range, the torque of the outer wheel is increased according to the first control method to obtain the first adjusted speed of the outer wheel; and the first target speed of the outer wheel is calculated according to the first calculation method. When the first target speed of the outer wheel is When the first adjusted speed is equal to the first target speed of the outer wheel, stop increasing the torque of the outer wheel; when the speed is in the medium speed range, reduce the torque of the inner wheel according to the second control method, and increase the torque of the outer wheel to obtain the second adjusted speed of the wheel; calculate the second target speed of the wheel according to the second calculation method, and when the second adjusted speed of the wheel is equal to the second target speed of the wheel, stop reducing the torque of the inner wheel and stop increasing the torque of the outer wheel; when the speed is in the high speed range, reduce the torque of the inner wheel according to the third control method to obtain the third adjusted speed of the inner wheel; calculate the third target speed of the inner wheel according to the third calculation method, and when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, stop reducing the torque of the inner wheel.

[0139] In this solution, the torque of the wheel is adjusted by different control methods through the judgment of the speed range of the steering angle and speed, and the wheel adjustment speed after the torque adjustment is obtained. The target speed of different speed ranges is calculated by different calculation methods, and then the target speed is compared with the adjustment speed. When the adjustment speed is equal to the target speed, the torque adjustment is stopped. This solution comprehensively analyzes and judges the adjustment speed and the calculated target speed from the steering angle, speed, and torque adjustment, and obtains the timing for each wheel to stop adjusting, which can realize stable and efficient steering of off-road vehicles and effectively improve the maneuverability, stability and safety of off-road vehicles.

[0140] Figure 4 , the embodiment shows a control flow chart of a steering control device for a four-wheel independent drive off-road platform.

[0141] In one embodiment, when the steering angle α of the off-road vehicle is 0, the off-road vehicle is traveling in a straight line, and the master controller evenly distributes the power of the four controllers. The four controllers respectively control the first drive mechanism 21, the second drive mechanism 22, the third drive mechanism 23 and the fourth drive mechanism 24. Therefore, the torques of the first drive mechanism 21, the second drive mechanism 22, the third drive mechanism 23 and the fourth drive mechanism 24 are equal. The torque of the first drive mechanism 21 is T1, the torque of the second drive mechanism 22 is T2, the torque of the third drive mechanism 23 is T3, the torque of the fourth drive mechanism 24 is T4, and the torque of the master controller is T 总 For example: T 总 =T1+T2+T3+T4, T1=T2=T3=T4.

[0142] Taking the off-road vehicle turning left as an example, the left front wheel 11 at the left front of the off-road vehicle and the left rear wheel 12 at the left rear of the off-road vehicle are inner wheels, and the right rear wheel 13 at the right rear of the off-road vehicle and the right front wheel 14 at the right front of the off-road vehicle are outer wheels.

[0143] When the off-road vehicle turns left, the steering angle α of the off-road vehicle is ≠ 0, and the speed range of the off-road vehicle is further determined.

[0144] When the speed of the off-road vehicle V h ≤25km, the off-road vehicle is in a low-speed range, at this time, the torque of the outer wheel is increased, that is, the torque of the right rear wheel and the right front wheel is increased, that is, by increasing the torque of the third drive mechanism 23, the total torque of the third drive mechanism 23 after the increase is T3+△t3, wherein T3 is the torque when the torque is not adjusted, and △t3 is the increased torque; and the torque of the fourth drive mechanism 24 is increased, the total torque of the fourth drive mechanism 24 after the increase is T4+△t4, wherein T4 is the torque when the torque is not adjusted, and △t4 is the increased torque; in the low-speed range, the torque of the inner wheel is not adjusted, that is, the torque of the first drive mechanism 11 and the second drive mechanism 22 remains unchanged.

[0145] Therefore, in the low speed range, the total torque T of the off-road vehicle 总 =T1+T2+(T3+△t3)+(T4+△t4).

[0146] The method of increasing the torque of the driving mechanism may be to increase the current within the tolerable range of the driving mechanism to increase the torque of the driving mechanism, or to increase the load of the driving mechanism to increase the torque, which is not limited in this embodiment.

[0147] When the torque of the third driving mechanism 23 and the fourth driving mechanism 24 is adjusted, the speeds of the corresponding right rear wheel and right front wheel change accordingly. At this time, the first adjustment speeds of the right rear wheel and the right front wheel can be obtained by the sensor on the driving mechanism. The first adjustment speed of the right rear wheel is V3T , the first adjustment speed of the right front wheel is V 4T For example.

[0148] In the low speed range, the first target speed of the right front wheel and the first target speed of the right rear wheel are also calculated.

[0149] Where V3 refers to the first target speed of the right rear wheel, V4 refers to the first target speed of the right front wheel, and V 1y is the running speed of the left front wheel, V 2y is the running speed of the left rear wheel, L is the wheelbase of the off-road vehicle; B is the track of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0150] Further determine the relationship between the first target speed of the right front wheel and the first adjusted speed of the right front wheel and the relationship between the first target speed of the right rear wheel and the first adjusted speed of the right rear wheel. When the first adjusted speed of the right rear wheel is V 3T = the first target speed V3 of the right rear wheel; the first adjustment speed of the right front wheel is V 4T = the first target speed V4 of the right front wheel, the adjustment of the torque is stopped, that is, at this time, the torque of the third drive mechanism and the fourth drive mechanism is not increased.

[0151] It can be understood that when the adjustment speed of one of the right front wheel and the right rear wheel is equal to the target speed of the wheel, the torque adjustment of the wheel is stopped, thereby achieving the effect of four-wheel independent drive.

[0152] When the speed of the off-road vehicle is 25km / h<V h ≤60km / h, the off-road vehicle is in the medium speed range, at this time, the torque of the inner wheel is reduced, and the torque of the outer wheel is increased, that is, the torque of the left front wheel and the left rear wheel is reduced, and the torque of the right rear wheel and the right front wheel is increased, that is, by reducing the torque of the first drive mechanism 21, the total torque of the first drive mechanism 21 after reduction is T1-△t1, wherein T1 is the torque when the torque is not adjusted, and △t1 is the reduced torque; the torque of the second drive mechanism 22 is reduced, so that the total torque of the second drive mechanism 222 after reduction is T2-△t2, wherein T2 is the torque when the torque is not adjusted, and △t2 is the reduced torque; the torque of the third drive mechanism 23 is increased, so that the total torque of the third drive mechanism 23 after increase is T3+△t3, wherein T3 is the torque when the torque is not adjusted, and △t3 is the increased torque; and the torque of the fourth drive mechanism 24 is increased, so that the total torque of the fourth drive mechanism 24 after increase is T4+△t4, wherein T4 is the torque when the torque is not adjusted, and △t4 is the increased torque.

[0153] It can be understood that in the medium speed range, the torque of both the inner wheel and the outer wheel needs to be adjusted.

[0154] In the medium speed range, the total torque T of the off-road vehicle 总 =(T1-△t1)+(T2-△t2)+(T3+△t3)+(T4+△t4).

[0155] The method of increasing the torque of the driving mechanism may be to increase the current within the tolerable range of the driving mechanism to increase the torque of the driving mechanism, or to increase the load of the driving mechanism to increase the torque, which is not limited in this embodiment.

[0156] The method of reducing the torque of the driving mechanism may be to reduce the current to reduce the torque of the driving mechanism within the range that the driving mechanism can bear, or to reduce the torque by reducing the load of the driving mechanism, which is not limited in this embodiment.

[0157] When the torques of the first drive mechanism 21, the second drive mechanism 22, the third drive mechanism 23 and the fourth drive mechanism 24 are adjusted, the speeds of the corresponding left front wheel, left rear wheel, right rear wheel and right front wheel change accordingly. At this time, the second adjusted speeds of the left front wheel, left rear wheel, right rear wheel and right front wheel can be obtained by the sensors on the drive mechanisms. The second adjusted speed of the left front wheel is V 1T； The second adjustment speed of the right rear wheel is V 2T， The second adjustment speed of the right rear wheel is V 4T , the second adjustment speed of the right front wheel is V 4T For example.

[0158] In the medium speed range, the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right rear wheel and the second target speed of the right front wheel are calculated respectively according to the following formula:

[0159] Where V1 refers to the second target speed of the left front wheel, V2 refers to the second target speed of the left rear wheel, V3 refers to the second target speed of the right rear wheel, V4 refers to the second target speed of the right front wheel, and V h is the speed of the off-road vehicle, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0160] In the medium speed range, the second target speed of each wheel is calculated based on the speed of the off-road vehicle.

[0161] Further determine the second target speed of the left front wheel and the second adjusted speed of the left front wheel; the second target speed of the left rear wheel and the second adjusted speed of the left rear wheel; the second target speed of the right front wheel and the second adjusted speed of the right front wheel and the second target speed of the right rear wheel and the second adjusted speed of the right rear wheel.

[0162] When the second adjustment speed of the left front wheel is V 1T= the second target speed V1 of the left front wheel; the second adjustment speed of the left rear wheel is V 2T = the second target speed V2 of the left rear wheel; the first adjustment speed of the right rear wheel is V 3T = the first target speed V3 of the right rear wheel; the first adjustment speed of the right front wheel is V 4T = the first target speed V4 of the right front wheel, the torque adjustment is stopped.

[0163] It can be understood that when the adjustment speed of one of the left front wheel, the left rear wheel, the right rear wheel and the right front wheel is equal to the target speed of the wheel, the torque adjustment of the wheel is stopped, thereby achieving the effect of four-wheel independent drive.

[0164] When the speed of the off-road vehicle V h >60km / h, the off-road vehicle is in a high-speed range. At this time, the torque of the inner wheel is reduced, that is, the torque of the left front wheel and the left rear wheel is reduced, that is, by reducing the torque of the first drive mechanism 21, the total torque of the first drive mechanism 21 after reduction is T1-△t1, wherein T1 is the torque when the torque is not adjusted, and △t1 is the reduced torque; the torque of the second drive mechanism 22 is reduced, so that the total torque of the second drive mechanism 222 after reduction is T2-△t2, wherein T2 is the torque when the torque is not adjusted, and △t2 is the reduced torque; in the high-speed range, the torque of the outer wheel is not adjusted, that is, the torque of the third drive mechanism and the fourth drive mechanism remains unchanged.

[0165] In the high-speed range, the total torque T of the off-road vehicle 总 =(T1-△t1)+(T2-△t2)+T3+T4.

[0166] The method of reducing the torque of the driving mechanism may be to reduce the current to reduce the torque of the driving mechanism within the range that the driving mechanism can bear, or to reduce the torque by reducing the load of the driving mechanism, which is not limited in this embodiment.

[0167] When the torque of the first driving mechanism 11 and the second driving mechanism 2 is adjusted, the speeds of the corresponding left front wheel and left rear wheel change accordingly. At this time, the third adjustment speed of the left front wheel and the left rear wheel can be obtained by the sensor on the driving mechanism. The third adjustment speed of the left front wheel is V 1T , the third adjustment speed of the left rear wheel is V 2T For example.

[0168] In the high-speed section, the third target speed of the left front wheel and the third target speed of the left rear wheel are also calculated.

[0169] Where, V1 is the third target speed of the left front wheel; V2 is the third target speed of the left rear wheel; V 3y is the speed of the right rear wheel, V4y is the running speed of the right front wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

[0170] A third target speed of the left front wheel and a third adjusted speed of the left front wheel as well as a third target speed of the left rear wheel and a third adjusted speed of the left rear wheel are further determined.

[0171] When the third adjustment speed of the left front wheel is V 1T = the third target speed V1 of the left front wheel; the third adjustment speed of the left rear wheel is V 2T = the third target speed V2 of the left rear wheel, the adjustment of the torque is stopped, that is, at this time, the torque of the first drive mechanism and the second drive mechanism is not reduced.

[0172] It can be understood that when the adjustment speed of one of the left front wheel and the left rear wheel is equal to the target speed of the wheel, the torque adjustment of the wheel is stopped, thereby achieving the effect of four-wheel independent drive.

[0173] In summary, in the present application, by acquiring the speed and steering angle of the off-road vehicle, when the steering angle is not zero, the speed range of the speed is further determined, and when the speed is in the low speed range, the torque of the outer wheel is increased according to the first control method to obtain the first adjusted speed of the outer wheel; and the first target speed of the outer wheel is calculated according to the first calculation method, and when the first adjusted speed of the outer wheel is equal to the first target speed of the outer wheel, the torque of the outer wheel is stopped from being increased; when the speed is in the medium speed range, the torque of the inner wheel is reduced according to the second control method, and the torque of the outer wheel is increased to obtain the second adjusted speed of the wheel; and the second target speed of the wheel is calculated according to the second calculation method, and when the second adjusted speed of the wheel is equal to the second target speed of the wheel, the torque of the inner wheel is stopped from being reduced, and the torque of the outer wheel is stopped from being increased; when the speed is in the high speed range, the torque of the inner wheel is reduced according to the third control method to obtain the third adjusted speed of the inner wheel; and the third target speed of the inner wheel is calculated according to the third calculation method, and when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, the torque of the inner wheel is stopped from being reduced.

[0174] In this solution, the torque of the wheel is adjusted by different control methods through the judgment of the speed range of the steering angle and speed to obtain the adjusted speed, and the target speed of different speed ranges is calculated by different calculation methods, and then the target speed is compared with the adjusted speed. When the adjusted speed is equal to the target speed, the torque adjustment is stopped. This solution comprehensively analyzes and judges the adjusted speed and the calculated target speed from the steering angle, speed, and torque adjustment, and obtains the timing to stop the adjustment, which can realize the stable and efficient steering of the off-road vehicle and effectively improve the maneuverability, stability and safety of the off-road vehicle.

[0175] Finally, it should be noted that the steering control method of the four-wheel independent drive off-road platform in the above embodiment is described by applying it to an off-road vehicle, but in addition to being applied to off-road vehicles, this solution can also be applied to other types of vehicles with four-wheel independent drive, such as four-wheel independent drive sedans, four-wheel independent drive commercial vehicles, four-wheel independent drive vans, etc. That is, four-wheel independent drive vehicles running on the ground platform are all within the protection scope of this application.

[0176] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A steering control method for a four-wheel independent drive off-road platform, applied to off-road vehicles, characterized in that: The off-road vehicle includes wheels, the wheels including an inner wheel and an outer wheel; Obtaining the speed and steering angle of the off-road vehicle; Get the running speeds of the left front wheel, left rear wheel, right front wheel and right rear wheel, which are V 1y 、V 2y 、V 3y and V 4y ; V 1y is the speed of the left front wheel, V 2y is the speed of the left rear wheel, V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel; According to the running speeds of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel, the speed V of the off-road vehicle is obtained. h , the speed V h The calculation formula is: Where: V h is the speed of the off-road vehicle, V 2y is the speed of the left rear wheel, V 3y is the running speed of the right rear wheel; When the steering angle is not zero, determining the speed interval in which the speed is located, the speed interval includes a low speed interval, a medium speed interval and a high speed interval; When the speed is in the low speed range, adjusting the torque of the wheel according to a first control method, the first control method is to increase the torque of the outer wheel to obtain a first adjusted speed of the outer wheel; and calculating a first target speed of the outer wheel according to a first calculation method, the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel, and when the first adjusted speed of the outer wheel is equal to the first target speed of the outer wheel, stopping increasing the torque of the outer wheel; When the off-road vehicle turns left, the inner wheels include a left front wheel and a left rear wheel, the outer wheels include a right front wheel and a right rear wheel, and the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are independently controlled; The first calculation method is to calculate the first target speed of the outer wheel according to the speed of the inner wheel, including calculating the first target speed of the right front wheel and the first target speed of the right rear wheel; The first target speed of the right rear wheel is calculated according to the running speed of the left rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The first target speed of the right front wheel is calculated according to the running speed of the left front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The calculation formulas for the first target speed of the right front wheel and the first target speed of the right rear wheel are: Where V3 refers to the first target speed of the right rear wheel, V4 refers to the first target speed of the right front wheel, and V 1y is the running speed of the left front wheel, V 2y is the running speed of the left rear wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle; When the speed is in the medium speed range, adjusting the torque of the wheel according to a second control method, wherein the second control method is to reduce the torque of the inner wheel and increase the torque of the outer wheel to obtain a second adjusted speed of the wheel; and calculating a second target speed of the wheel according to a second calculation method, wherein the second calculation method is to calculate the second target speed of the wheel according to the speed of the off-road vehicle; When the second adjusted speed of the wheel is equal to the second target speed of the wheel, stopping reducing the torque of the inner wheel and stopping increasing the torque of the outer wheel; The second calculation method is to calculate the second target speed of the wheels according to the speed of the off-road vehicle, including calculating the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel; The second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are calculated according to the speed of the off-road vehicle, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The calculation formulas for the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are: Where V1 refers to the second target speed of the left front wheel, V2 refers to the second target speed of the left rear wheel, V3 refers to the second target speed of the right rear wheel, V4 refers to the second target speed of the right front wheel, and V h is the speed of the off-road vehicle, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle; When the speed is in the high speed range, adjusting the torque of the wheel according to a third control method, the third control method is to reduce the torque of the inner wheel to obtain a third adjusted speed of the inner wheel; and calculating a third target speed of the inner wheel according to a third calculation method, the third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel; when the third adjusted speed of the inner wheel is equal to the third target speed of the inner wheel, stopping reducing the torque of the inner wheel; The third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel, including calculating the third target speed of the left front wheel and the third target speed of the left rear wheel; The third target speed of the left front wheel is calculated according to the running speed of the right front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The third target speed of the left rear wheel is calculated according to the running speed of the right rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The third target speed of the left front wheel and the third target speed of the left rear wheel are calculated as follows: Wherein, V1 is the third target speed of the left front wheel; V2 is the third target speed of the left rear wheel; V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

2. The steering control method of the four-wheel independent drive off-road platform according to claim 1, wherein the speed interval of the speed of the off-road vehicle is determined, and the speed interval includes a low speed interval, a medium speed interval and a high speed interval, and is characterized in that: When V h ≤25km, the speed interval of the off-road vehicle is in the low speed interval; When 25km / h<V h When the speed is ≤60km / h, the speed interval of the off-road vehicle is in the medium speed interval; When V h >60km / h, the speed range of the speed of the off-road vehicle is in the high speed range.

3. A four-wheel independent drive off-road platform steering control device, applied to off-road vehicles, characterized by: The off-road vehicle comprises inner wheels and outer wheels. When the off-road vehicle turns left, the inner wheels comprise a left front wheel and a left rear wheel, the outer wheels comprise a right front wheel and a right rear wheel, and the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are independently controlled. Four driving mechanisms are respectively connected to the left front wheel, the left rear wheel, the right front wheel and the right rear wheel; Four controllers are connected to the four driving mechanisms respectively, and the four controllers control the four driving mechanisms respectively; A master controller connected to the four controllers to control the four controllers; The master controller also includes: An acquisition module, used for acquiring the speed and steering angle of the off-road vehicle; Get the running speeds of the left front wheel, left rear wheel, right front wheel and right rear wheel, which are V 1y 、V 2y 、V 3y and V 4y ; V 1y is the speed of the left front wheel, V 2y is the speed of the left rear wheel, V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel; According to the running speeds of the left front wheel, the left rear wheel, the right front wheel and the right rear wheel, the speed V of the off-road vehicle is obtained. h , the speed V h The calculation formula is: Where: V h is the speed of the off-road vehicle, V 2y is the speed of the left rear wheel, V 3y is the running speed of the right rear wheel; A first judgment module, used for judging the speed interval of the speed when the steering angle is not zero, the speed interval including a low speed interval, a medium speed interval and a high speed interval; a first control module, configured to adjust the torque of the wheel according to a first control method when the speed is in a low speed range, wherein the first control method is to increase the torque of the outer wheel to obtain a first adjusted speed of the outer wheel; a first calculation module, configured to calculate a first target speed of the wheel according to a first calculation method when the speed is in a low speed range; the first calculation method is to calculate the first target speed of the outer wheel according to the running speed of the inner wheel; a first judgment submodule, configured to stop increasing the torque of the outer wheel when the first adjustment speed of the outer wheel is equal to the first target speed of the outer wheel; When the off-road vehicle turns left, the inner wheels include a left front wheel and a left rear wheel, the outer wheels include a right front wheel and a right rear wheel, and the left front wheel, the left rear wheel, the right front wheel and the right rear wheel are independently controlled; The first calculation method is to calculate the first target speed of the outer wheel according to the speed of the inner wheel, including calculating the first target speed of the right front wheel and the first target speed of the right rear wheel; The first target speed of the right rear wheel is calculated according to the running speed of the left rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The first target speed of the right front wheel is calculated according to the running speed of the left front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The calculation formulas for the first target speed of the right front wheel and the first target speed of the right rear wheel are: Where V3 refers to the first target speed of the right rear wheel, V4 refers to the first target speed of the right front wheel, and V 1y is the running speed of the left front wheel, V 2y is the running speed of the left rear wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle; a second control module, configured to adjust the torque of the wheel according to a second control method when the speed is in a medium speed range, wherein the second control method is to reduce the torque of the inner wheel and increase the torque of the outer wheel to obtain a second adjusted speed of the wheel; a second calculation module, configured to calculate a second target speed of the wheel according to a second calculation method when the speed is in a medium speed range, wherein the second calculation method is to calculate the second target speed of the wheel according to the speed of the off-road vehicle; a second judgment submodule, configured to stop reducing the torque of the inner wheel and stop increasing the torque of the outer wheel when the second adjustment speed of the wheel is equal to the second target speed of the wheel; The second calculation method is to calculate the second target speed of the wheels according to the speed of the off-road vehicle, including calculating the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel; The second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are calculated according to the speed of the off-road vehicle, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The calculation formulas for the second target speed of the left front wheel, the second target speed of the left rear wheel, the second target speed of the right front wheel and the second target speed of the right rear wheel are: Where V1 refers to the second target speed of the left front wheel, V2 refers to the second target speed of the left rear wheel, V3 refers to the second target speed of the right rear wheel, V4 refers to the second target speed of the right front wheel, and V h is the speed of the off-road vehicle, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle; a third control module, configured to adjust the torque of the wheel according to a third control method when the speed is in a high speed range, wherein the third control method is to reduce the torque of the inner wheel to obtain a third adjusted speed of the inner wheel; a third calculation module, configured to calculate a third target speed of the inner wheel according to a third calculation method when the speed is in a high speed range, wherein the third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel; a third judgment submodule, configured to stop reducing the torque of the inner wheel when the third adjustment speed of the inner wheel is equal to the third target speed of the inner wheel; The third calculation method is to calculate the third target speed of the inner wheel according to the running speed of the outer wheel, including calculating the third target speed of the left front wheel and the third target speed of the left rear wheel; The third target speed of the left front wheel is calculated according to the running speed of the right front wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The third target speed of the left rear wheel is calculated according to the running speed of the right rear wheel, the wheelbase of the off-road vehicle, the track width of the off-road vehicle and the steering angle of the off-road vehicle; The third target speed of the left front wheel and the third target speed of the left rear wheel are calculated as follows: Wherein, V1 is the third target speed of the left front wheel; V2 is the third target speed of the left rear wheel; V 3y is the speed of the right rear wheel, V 4y is the running speed of the right front wheel, L is the wheelbase of the off-road vehicle; B is the track width of the off-road vehicle; α is the steering angle of the off-road vehicle.

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