CN113335417B - Foldable and unfoldable reconstructed variable-wheel-track all-terrain trolley and control method thereof - Google Patents

Abstract

The invention relates to the field of wheeled robots, in particular to a foldable and reconfigurable all-terrain vehicle with variable wheelbase and a control method thereof. The overall structure of the invented foldable and reconfigurable all-terrain vehicle with variable wheelbase is composed of attitude adjustment assembly, driving wheel assembly, bottom support plate, top support plate and first and second driven wheel assemblies; its control structure is controlled by attitude perception module, steering control module, angle control module and four-wheel speed coordination control module. The car body is completely symmetrical with respect to the neutral plane of the bottom support plate and the top support plate. The wheel base and shape of the trolley can be continuously changed through multiple full-circle turning and folding mechanisms, so that it has the ability to cross different terrain obstacles. At the same time, due to the It does not distinguish between front and back and front and rear sides, has all-round maneuverability, and further improves its stability, making this wheeled trolley have a wide range of social application prospects.

Description

A foldable and reconfigurable variable wheelbase all-terrain vehicle and its control method

technical field

The invention relates to the field of wheeled robots, in particular to a foldable and reconfigurable all-terrain vehicle with variable wheelbase and a control method thereof.

Background technique

As a kind of mobile robot, wheeled robot has a faster moving speed than legged robot, but its adaptability to complex environments is poor, and it is often used to perform tasks such as material transportation, emergency rescue, and security patrols. Traditional wheeled trolleys have a fixed wheelbase and a fixed chassis, and have obvious physical front and back sides and front and rear sides. Therefore, when facing complex terrain, they do not have the ability to cross obstacles, recover from dumping, and be flexible and foldable. The above-mentioned ability is of great significance for adapting to the field environment with complex terrain and overcoming the harsh terrain without good road conditions. The purpose of the present invention is to propose a foldable trolley with multi-wheel drive, variable wheelbase, dump self-recovery function and its control method, so as to meet the needs of the trolley for complex tasks and realize the trolley climbing stairs, climbing Functions such as pipes, climbing gaps, climbing or passing through complex terrain such as height limit poles, and balance cars.

Contents of the invention

The problem to be solved in the present invention is to design a foldable and reconfigurable all-terrain car with variable wheelbase and its control method, so as to ensure the high-speed movement ability of the wheeled robot and further improve the adaptability and maneuverability of the robot to the complex terrain environment .

The technical scheme that the present invention solves its technical problem adopts is:

A foldable and reconfigurable all-terrain vehicle with variable wheelbase, its overall structure is composed of a posture adjustment assembly, a driving wheel assembly, a bottom support plate, a top support plate, and first and second driven wheel assemblies.

Wherein, the bottom supporting board is composed of the second main board, the second and the fourth side board; the top supporting board is composed of the first main board, the first and the third side board; the attitude adjustment assembly is fixed on the second main board of the bottom supporting board, The first and second driven wheel assemblies are respectively installed on the second and fourth side plates of the bottom support plate; the two sides of the vehicle transverse axis of the attitude adjustment assembly pass through the first and second of the first and second driven wheel assemblies respectively. The connecting seat is fixedly connected with it, and is connected with the first and second driven wheels of the first and second driven wheel assemblies through the rotating pair; the second position of the bottom support plate is realized by controlling the vehicle body attitude control motor in the attitude adjustment assembly. The included angle between the second main board and the second and fourth side panels is adjustable, that is, the function of the trolley can be folded and reconfigured to adapt to various terrain environments; the first and fourth wheel assemblies of the drive wheel assembly are respectively Installed on the second and fourth side plates of the bottom support plate, its second and third wheel assemblies are installed on the second main plate of the bottom support plate, in the initial state, the second main plate of the bottom support plate and the first 2. When the fourth side plate is on the same plane, the driving wheels of the first, second, third and fourth wheel assemblies are coaxial. At this time, the driving wheel assembly and the first and second driven wheel assemblies are arranged in The two ends of the trolley; the top support plate and the bottom support plate sandwich the rest of the trolley in the middle to play a protective role.

Its attitude adjustment assembly is composed of the vehicle transverse shaft, the vehicle body attitude control motor, the driven gear, the driving gear, the first and the second conductive slip ring assembly; wherein, the first conductive slip ring assembly is composed of the first conductive outer ring, the second conductive slip ring assembly A conductive inner ring, the first fixed seat, the second conductive slip ring assembly is composed of the second conductive outer ring, the second conductive inner ring, and the second fixed seat; the first and second conductive inner rings are fixedly connected to the transverse shaft of the vehicle , and are respectively connected to the first and second conductive outer rings through the rotating pair; the first and second conductive outer rings are fixedly connected to the first and second fixing seats, while the first and second fixing seats are fixed to the second main board connection; the attitude control motor of the car body is also fixed on the second main board, and its output shaft is connected with the driving gear, and the power is transmitted to the horizontal shaft of the car through the driven gear meshed with the driving gear, so that the second main board and the second main board can be changed. , The included angle on the fourth side plate is used to realize the wheelbase adjustment between the first and fourth wheel assemblies and the second and third wheel assemblies; through the first and second conductive slip ring assemblies, the first and second The components between the second main boards can still maintain good electrical connection with the components on the first, second, third and fourth side boards after several times of complete revolutions.

It can work in the working mode of continuously variable wheelbase, and does not distinguish between front and back and front and rear sides; the car body is completely symmetrical about the neutral plane of the bottom support plate and the top support plate. The trolley can work in the mode of short wheelbase and long wheelbase, and the wheelbase can be continuously variable. At the same time, the first and second main boards can be connected with the first, second, and third by controlling the body attitude control motor in the attitude adjustment component. The active flip between the fourth side plate and the fourth side plate enables the car to have the ability to overcome obstacles.

A control method for a foldable and reconfigurable variable wheelbase all-terrain vehicle, the control architecture of which is composed of an attitude perception module, a steering control module, an included angle control module and a four-wheel speed cooperative control module;

整体偏航姿态角为

整体俯仰姿态角由β₁,β₂共同决定，为Among them, the posture perception module is composed of the postures of the first and second main boards and the postures of the first, second, third and fourth side boards, and the postures of the first and second main boards (α ₁ , β ₁ , γ ₁ ) Measured by the attitude sensor installed on the second main board, the attitudes (α ₂ , β ₂ , γ ₂ ) of the first, second, third and fourth side plates are measured by the attitude sensor installed on the first side plate Therefore, the overall roll attitude angle of the car is

The overall yaw attitude angle is

The overall pitching attitude angle is jointly determined by β ₁ and β ₂ , which is

θ=π+β ₁ -β ₂

Among them, l ₁ , l ₂ are the wheel bases of the second and third wheel assemblies, the first and fourth wheel assemblies and the first and second passive wheel assemblies respectively; θ is the first, second, third and fourth The included angle between the side plate and the first and second main boards; D is the wheel base between the second and third wheel assemblies and the first and fourth wheel assemblies.

得到期望的夹角后，结合姿态感知模块中测量的实际夹角设计控制器，控制姿态调节组件中的车体姿态控制电机，即可实现小车的轮距/夹角控制。The wheelbase/included angle control module is based on attitude perception, the expected wheelbase D _d is known, and the expected included angle can be calculated

After obtaining the desired angle, design the controller based on the actual angle measured in the attitude perception module, and control the body attitude control motor in the attitude adjustment component to realize the wheelbase/angle control of the car.

In the steering control module, the expected and actual yaw angles are known to be γ _d , γ respectively. Since the car has no steering mechanism, it can only steer through the four-wheel differential, and the smaller the wheel base, the faster the car can turn, and the car can be designed The steering controller is

e _γ =γ-γ _d

Among them, k _Pi (D), k _Ii (D), k _Di (D), i=1,2,3,4 are the proportional, integral and differential control parameters in the steering controller, when i=1,2 , k _Pi (D), k _Ii (D), k _Di (D)≥0, when i=3,4, k _Pi (D), k _Ii (D), k _Di (D)≤0, and |k _Pi (D)|, |k _Ii (D)|, |k _Di (D)|, i=1, 2, 3, 4 are proportional to the size of the wheel base D, to ensure uniform changes in steering control.

当k＝-1时，代表左转，当k＝1时，代表右转。同时可知，第一、第二、第三和第四轮组件的实际速度分别为v₁,v₂,v₃,v₄，各轮组件的实际速度与期望速度的差值大小并不一致，为了保证四轮驱动的协同控制，设计四轮速度协同控制器为In the four-wheel speed cooperative control module, the overall expected and actual speeds of the car are known to be v _d , v respectively, and the curvature radius of the walking track is R, which can be decomposed into the expectations of the first, second, third and fourth wheel components The speed is

When k=-1, it represents a left turn, and when k=1, it represents a right turn. At the same time, it can be known that the actual speeds of the first, second, third and fourth wheel assemblies are v ₁ , v ₂ , v ₃ , v ₄ respectively, and the difference between the actual speed and the expected speed of each wheel assembly is not consistent. To ensure the coordinated control of the four-wheel drive, the four-wheel speed coordinated controller is designed as

Among them, v _i ′ _d , i=1, 2, 3, 4 is the expected speed of each new wheel assembly generated for cooperative control, c ₁ is the overall speed coordination factor, c ₂ is its own expected speed tracking factor, c ₁ The larger the speed is, the faster the coordination is, and the larger c ₂ is, the faster the expected speed of speed tracking itself will be.

Compared with the prior art, the present invention has the beneficial effects: the present invention continuously changes the wheel base and shape of the trolley through multiple round-turning foldable mechanisms, so that it has the ability to cross different terrain obstacles, and at the same time due to its It does not distinguish between front and back, front and rear sides, possesses all-round maneuverability, and further improves its stability, making this wheeled trolley have a wide range of social application prospects.

Description of drawings

Figure 1 The overall schematic diagram of the foldable and reconfigurable all-terrain car with variable wheelbase;

Figure 2 internal structure diagram;

Figure 3 Explosion schematic diagram;

Fig. 4 is a schematic diagram of attitude adjustment components;

Figure 5 is a schematic diagram of short wheelbase working mode;

Fig. 6 Schematic diagram of long wheelbase working mode;

Figure 7 schematic diagram of wheel assembly;

Figure 8 Schematic diagram of the car control architecture;

Figure 9 is a schematic diagram of the structural parameters of the trolley;

Figure 10 Schematic diagram of coordinated control of four-wheel speed of the trolley;

Among the figure: attitude adjustment assembly (1), driving wheel assembly (2), bottom support plate (3-1), top support plate (3-2), first and second driven wheel assembly (4-1, 4- 2), the first, second, third and fourth wheel assemblies (5-1, 5-2, 5-3, 5-4), the vehicle transverse shaft (6), the vehicle body attitude control motor (7), Driven gear (8), driving gear (9), first and second conductive slip ring assemblies (10-1, 10-2), first, second, third and fourth side plates (11-1, 11-2, 11-3, 11-4), the first and second main boards (12-1, 12-2), the first and second conductive outer rings (13-1, 13-2), the first, The second conductive inner ring (14-1, 14-2), the first and second fixing seats (15-1, 15-2), the first and second connecting seats (16-1, 16-2), the first One, the second driven wheel (17-1,17-2), traveling motor (18), driving wheel (19).

detailed description

The present invention will be further described in conjunction with the accompanying drawings.

The problem to be solved in the present invention is to design a foldable and reconfigurable all-terrain car with variable wheelbase and its control method, so as to ensure the high-speed movement ability of the wheeled robot and further improve the adaptability and maneuverability of the robot to the complex terrain environment .

The technical scheme that the present invention solves its technical problem adopts is:

A foldable and reconfigurable all-terrain car with variable wheelbase, as shown in Figure 1, its overall structure consists of a posture adjustment assembly (1), a driving wheel assembly (2), a bottom support plate (3-1), a top support plate (3-2) and the first and second driven wheel assembly (4-1, 4-2) constitute;

Wherein, the bottom supporting board (3-1) is made up of the second main board (12-2), the second and the fourth side boards (11-2, 11-4); the top supporting board (3-2) is made up of the first main board (12-1), first and third side plates (11-1, 11-3); the attitude adjustment assembly (1) is fixed on the second main board (12-2) of the bottom support plate (3-1) , the first and second driven wheel assemblies (4-1, 4-2) are installed on the second and fourth side plates (11-2, 11-4) of the bottom support plate (3-1) respectively; attitude adjustment Both sides of the transverse axis (6) of the assembly (1) respectively pass through the first and second connecting seats (16-1, 16-2) of the first and second driven wheel assemblies (4-1, 4-2) , and fixedly connected with it, and at the same time connected with the first and second driven wheels (17-1, 17-2) of the first and second driven wheel assemblies (4-1, 4-2) through a rotating pair; by controlling The vehicle body attitude control motor (7) in the attitude adjustment assembly (1) realizes the second main board (12-2) of the bottom support plate (3-1) and the second and fourth side plates (11-2, 11-4) ) between the adjustable angle, that is, the foldable and reconfigurable variable wheelbase function of the trolley, to adapt to various terrain environments; the first and fourth wheel assemblies (5-1, 5- 4) respectively installed on the second and fourth side plates (11-2, 11-4) of the bottom support plate (3-1), its second and third wheel assemblies (5-2, 5-3) Installed on the second main board (12-2) of the bottom support plate (3-1), in the initial state, the second main board (12-2) of the bottom support plate (3-1) and the second and fourth When the side plates (11-2, 11-4) are on the same plane, the driving wheels of the first, second, third and fourth wheel assemblies (5-1, 5-2, 5-3, 5-4) (19) Coaxial line, at this time, the driving wheel assembly (2) and the first and second driven wheel assemblies (4-1, 4-2) are arranged at the two ends of the trolley, as shown in Figure 2; the top support plate (3-2) and the bottom support plate (3-1) clamp the remaining parts of the trolley in the middle to play a protective role.

Its attitude adjustment assembly (1) consists of a vehicle cross shaft (6), a vehicle body attitude control motor (7), a driven gear (8), a drive gear (9), a first and a second conductive slip ring assembly (10- 1,10-2), as shown in Figure 4; wherein, the first conductive slip ring assembly consists of the first conductive outer ring (13-1), the first conductive inner ring (14-1), the first fixed seat ( 15-1), the second conductive slip ring assembly is made up of the second conductive outer ring (13-2), the second conductive inner ring (14-2), and the second fixed seat (15-2); the first, the second The two conductive inner rings (14-1, 14-2) are fixedly connected to the vehicle transverse shaft (6), and are respectively connected to the first and second conductive outer rings (13-1, 13-2) through rotating pairs; the first , the second conductive outer ring (13-1, 13-2) is fixedly connected with the first and second fixing seats (15-1, 15-2), and the first and second fixing seats (15-1, 15-2) 2) is fixedly connected with the second main board (12-2); the car body attitude control motor (7) is also fixed on the second main board (12-2), and its output shaft is connected with the driving gear (9), and the power is passed through The driven gear (8) meshed with the drive gear (9) is transmitted to the cross shaft (6), so that the second main board (12-2) and the second and fourth side plates (11-2, 11) can be changed. -4) to realize the wheelbase adjustment between the first and fourth wheel assemblies (5-1, 5-4) and the second and third wheel assemblies (5-2, 5-3); The first and second conductive slip ring assemblies (10-1, 10-2) can ensure that the elements between the first and second main boards (12-1, 12-2) can still function after multiple full-circle rotations. Good electrical connection is maintained with components on the first, second, third and fourth side plates (11-1, 11-2, 11-3, 11-4).

It can work in the working mode of continuously variable wheelbase, and does not distinguish between front and rear sides and front and rear sides; the car body is completely symmetrical about the neutral plane of the bottom support plate (3-1) and the top support plate (3-2). As shown in Figure 5 and Figure 6, the trolley can work in the short wheelbase and long wheelbase modes, and the wheelbase can be continuously variable, and at the same time, it can be realized by controlling the body attitude control motor (7) in the attitude adjustment component (1). Active connection between the first and second main boards (12-1, 12-2) and the first, second, third and fourth side plates (11-1, 11-2, 11-3, 11-4) Turn over, so that the car has the ability to overcome obstacles.

A control method for a foldable and reconfigurable variable wheelbase all-terrain vehicle, as shown in Figure 8, the control architecture is composed of an attitude perception module, a wheelbase/angle control module, a steering control module and a four-wheel speed cooperative control module;

整体偏航姿态角为

整体俯仰姿态角由β₁,β₂共同决定，为Wherein, as shown in Figure 9, the attitude perception module is composed of the attitude of the first and second main boards (12-1, 12-2) and the first, second, third and fourth side plates (11-1, 11-2). 2, 11-3, 11-4), the postures (α ₁ , β ₁ , γ ₁ ) of the first and second main boards (12-1, 12-2) are formed by installing on the second main board (12- 2) The attitude sensors on the first, second, third and fourth side panels (11-1, 11-2, 11-3, 11-4) measure the attitudes (α ₂ , β ₂ , γ ₂ ) is measured by the attitude sensor installed on the first side plate (11-1), so that the overall rolling attitude angle of the car is

The overall yaw attitude angle is

The overall pitching attitude angle is jointly determined by β ₁ and β ₂ , which is

θ=π+β ₁ -β ₂

Among them, l ₁ and l ₂ are respectively the second and third wheel assemblies (5-2, 5-3) and the first and fourth wheel assemblies (5-1, 5-4) and the first and second driven wheels The track of assembly (4-1,4-2); θ is the first, second, third and fourth side plate (11-1,11-2,11-3,11-4) The included angle of the second main board (12-1,12-2); D is the second, the third wheel assembly (5-2,5-3) and the first, the fourth wheel assembly (5-1,5-4 ) wheelbase.

得到期望的夹角后，结合姿态感知模块中测量的实际夹角设计控制器，控制姿态调节组件(1)中的车体姿态控制电机(7)，即可实现小车的轮距/夹角控制。The wheelbase/included angle control module is based on attitude perception, the expected wheelbase D _d is known, and the expected included angle can be calculated

After obtaining the desired included angle, design the controller in combination with the actual included angle measured in the attitude perception module, and control the vehicle body attitude control motor (7) in the attitude adjustment component (1) to realize the wheelbase/angle control of the trolley .

In the steering control module, the expected and actual yaw angles are known to be γ _d , γ respectively. Since the car has no steering mechanism, it can only steer through the four-wheel differential, and the smaller the wheel base, the faster the car turns, and the car can be designed The steering controller is

e _γ =γ-γ _d

Among them, k _Pi (D), k _Ii (D), k _Di (D), i=1,2,3,4 are the proportional, integral and differential control parameters in the steering controller, when i=1,2 , k _Pi (D), k _Ii (D), k _Di (D)≥0, when i=3,4, k _Pi (D), k _Ii (D), k _Di (D)≤0, and |k _Pi (D)|, |k _Ii (D)|, |k _Di (D)|, i=1, 2, 3, 4 are proportional to the size of the wheel base D, to ensure uniform changes in steering control.

当k＝-1时，代表左转，当k＝1时，代表右转。同时可知，第一、第二、第三和第四轮组件(5-1、5-2、5-3、5-4)的实际速度分别为v₁,v₂,v₃,v₄，各轮组件的实际速度与期望速度的差值大小并不一致，为了保证四轮驱动的协同控制，如图10所示，设计四轮速度协同控制器为In the four-wheel speed cooperative control module, the overall expected and actual speeds of the car are known to be v _d , v respectively, and the curvature radius of the walking track is R, which can be decomposed into the first, second, third and fourth wheel components (5 -1, 5-2, 5-3, 5-4) the expected speeds are respectively

When k=-1, it represents a left turn, and when k=1, it represents a right turn. At the same time, it can be seen that the actual speeds of the first, second, third and fourth wheel assemblies (5-1, 5-2, 5-3, 5-4) are respectively v ₁ , v ₂ , v ₃ , v ₄ , The difference between the actual speed of each wheel assembly and the expected speed is not consistent. In order to ensure the coordinated control of the four-wheel drive, as shown in Figure 10, the four-wheel speed cooperative controller is designed as

Among them, v _i ′ _d , i=1, 2, 3, 4 is the expected speed of each new wheel assembly generated for cooperative control, c ₁ is the overall speed coordination factor, c ₂ is its own expected speed tracking factor, c ₁ The larger the speed is, the faster the coordination is, and the larger c ₂ is, the faster the expected speed of speed tracking itself will be.

Compared with the prior art, the present invention has the beneficial effects: the present invention continuously changes the wheel base and shape of the trolley through multiple round-turning foldable mechanisms, so that it has the ability to cross different terrain obstacles, and at the same time due to its It does not distinguish between front and back, front and rear sides, possesses all-round maneuverability, and further improves its stability, making this wheeled trolley have a wide range of social application prospects.

Claims (4)

1. A foldable and reconfigurable all-terrain car with variable wheelbase, characterized in that: its overall structure consists of a posture adjustment assembly (1), a drive wheel assembly (2), a bottom support plate (3-1), and a top support plate (3-2) and the first and second driven wheel assembly (4-1, 4-2) constitute; Wherein, the bottom supporting board (3-1) is made up of the second main board (12-2), the second and the fourth side boards (11-2, 11-4); the top supporting board (3-2) is made up of the first main board (12-1), first and third side plates (11-1, 11-3); the attitude adjustment assembly (1) is fixed on the second main board (12-2) of the bottom support plate (3-1) , the first and second driven wheel assemblies (4-1, 4-2) are installed on the second and fourth side plates (11-2, 11-4) of the bottom support plate (3-1) respectively; attitude adjustment Both sides of the transverse axis (6) of the assembly (1) respectively pass through the first and second connecting seats (16-1, 16-2) of the first and second driven wheel assemblies (4-1, 4-2) , and is fixedly connected with it, and is connected with the first and second driven wheels (17-1, 17-2) of the first and second driven wheel assemblies (4-1, 4-2) at the same time through a rotating pair; by controlling The vehicle body attitude control motor (7) in the attitude adjustment assembly (1) realizes the second main board (12-2) of the bottom support plate (3-1) and the second and fourth side plates (11-2, 11-4) ) between the adjustable angle, that is, the foldable and reconfigurable variable track function of the trolley, to adapt to various terrain environments; the first and fourth wheel assemblies (5-1, 5- 4) respectively installed on the second and fourth side plates (11-2, 11-4) of the bottom support plate (3-1), its second and third wheel assemblies (5-2, 5-3) Installed on the second main board (12-2) of the bottom support plate (3-1), in the initial state, the second main board (12-2) of the bottom support plate (3-1) and the second and fourth When the side plates (11-2, 11-4) are on the same plane, the driving wheels of the first, second, third and fourth wheel assemblies (5-1, 5-2, 5-3, 5-4) (19) Coaxial line, at this time, the drive wheel assembly (2) and the first and second driven wheel assemblies (4-1, 4-2) are arranged at the two ends of the trolley; the top support plate (3-2) and The bottom support plate (3-1) clamps the remaining parts of the dolly in the middle to play a protective role. 2. A control method for the foldable and reconfigurable all-terrain vehicle with variable wheelbase as claimed in claim 1, characterized in that: its control framework consists of a posture perception module, a wheelbase/angle control module, and a steering control module. module and four-wheel speed cooperative control module; Wherein, the posture sensing module is composed of the postures of the first and second main boards (12-1, 12-2) and the first, second, third and fourth side boards (11-1, 11-2, 11-3, 11-4), the attitude (α ₁ , β ₁ , γ ₁ ) of the first and second main boards (12-1, 12-2) is determined by the attitude sensor installed on the second main board (12-2) Measured, the attitudes (α ₂ , β ₂ , γ ₂ ) of the first, second, third and fourth side plates (11-1, 11-2, 11-3, 11-4) are determined by the The attitude sensor on the side plate (11-1) is measured, so that the overall rolling attitude angle of the car is

The overall yaw attitude angle is

The overall pitching attitude angle is jointly determined by β ₁ and β ₂ , which is

θ=π+β ₁ -β ₂

Among them, l ₁ and l ₂ are respectively the second and third wheel assemblies (5-2, 5-3) and the first and fourth wheel assemblies (5-1, 5-4) and the first and second driven wheels The track of assembly (4-1,4-2); θ is the first, second, third and fourth side plate (11-1,11-2,11-3,11-4) The included angle of the second main board (12-1,12-2); D is the second, the third wheel assembly (5-2,5-3) and the first, the fourth wheel assembly (5-1,5-4 ) wheelbase; The wheelbase/included angle control module is based on attitude perception, the expected wheelbase D _d is known, and the expected included angle can be calculated

After obtaining the desired included angle, design the controller in combination with the actual included angle measured in the attitude perception module, and control the vehicle body attitude control motor (7) in the attitude adjustment component (1) to realize the wheelbase/angle control of the trolley ; In the steering control module, the expected and actual yaw angles are known to be γ _d , γ respectively. Since the car has no steering mechanism, it can only steer through the four-wheel differential, and the smaller the wheel base, the faster the car can turn, and the car can be designed The steering controller is

e _γ =γ-γ _d Among them, k _Pi (D), k _Ii (D), k _Di (D), i=1,2,3,4 are the proportional, integral and differential control parameters in the steering controller, when i=1,2 , k _Pi (D), k _Ii (D), k _Di (D)≥0, when i=3,4, k _Pi (D), k _Ii (D), k _Di (D)≤0, and |k _Pi (D)|,|k _Ii (D)|,|k _Di (D)|, i=1, 2, 3, 4 is proportional to the size of the wheelbase D, to ensure the uniform change of steering control; In the four-wheel speed cooperative control module, the overall expected and actual speeds of the car are known to be v _d , v respectively, and the curvature radius of the walking track is R, which can be decomposed into the first, second, third and fourth wheel components (5 -1, 5-2, 5-3, 5-4) the expected speeds are respectively

When k=-1, it represents turning left, and when k=1, it represents turning right; simultaneously it can be known that the first, second, third and fourth wheel assemblies (5-1, 5-2, 5-3, 5-4) The actual speeds are v ₁ , v ₂ , v ₃ , v ₄ respectively, and the difference between the actual speed of each wheel assembly and the expected speed is not consistent. In order to ensure the coordinated control of the four-wheel drive, the design of the four-wheel speed Co-controller is

Among them, v′ _id , i=1, 2, 3, 4 is the new expected speed of each wheel assembly generated for cooperative control, c ₁ is the overall speed coordination factor, c ₂ is its own expected speed tracking factor, the more c ₁ The faster the maximum speed coordination is, the larger the c ₂ is, the faster the expected speed of the speed tracking itself will be. 3. A foldable and reconfigurable all-terrain car with variable wheelbase as claimed in claim 1, characterized in that: its posture adjustment assembly (1) consists of a vehicle transverse axis (6), a vehicle body posture control motor (7 ), driven gear (8), driving gear (9), first and second conductive slip ring assemblies (10-1, 10-2); wherein, the first conductive slip ring assembly consists of the first conductive outer ring ( 13-1), the first conductive inner ring (14-1), the first fixed seat (15-1), the second conductive slip ring assembly is composed of the second conductive outer ring (13-2), the second conductive inner ring (14-2), the second fixed seat (15-2); the first and second conductive inner rings (14-1, 14-2) are fixedly connected with the vehicle transverse shaft (6), and are respectively connected with the first, The second conductive outer ring (13-1, 13-2) is connected through a rotating pair; the first and second conductive outer rings (13-1, 13-2) are connected to the first and second fixed seats (15-1, 15 -2) Fixed connection, while the first and second fixing bases (15-1, 15-2) are fixedly connected with the second main board (12-2); the body attitude control motor (7) is also fixed on the second main board (12-2), its output shaft is connected with the driving gear (9), and the power is transmitted to the cross shaft (6) through the driven gear (8) meshed with the driving gear (9), so that the second The angle between the main board (12-2) and the second and fourth side plates (11-2, 11-4), to realize the first and fourth wheel assembly (5-1, 5-4) and the second, Wheelbase adjustment between the third wheel assembly (5-2, 5-3); through the first and second conductive slip ring assemblies (10-1, 10-2), the first and second main boards (12 -1, 12-2), the elements between the first, second, third and fourth side plates (11-1, 11-2, 11-3, 11- 4) The components on the board maintain a good electrical connection. 4. A foldable and reconfigurable all-terrain trolley with variable wheelbase as claimed in claim 1, characterized in that: it can work in the working mode of continuously variable wheelbase, and does not distinguish between front and back and front and rear sides; The car body is completely symmetrical about the neutral plane of the bottom support plate (3-1) and the top support plate (3-2); The car body posture control motor (7) in the control posture adjustment assembly (1) realizes the first and second main boards (12-1, 12-2) and the first, second, third and fourth side boards (11-2) 1, 11-2, 11-3, 11-4) between the active flip, so that the car has the ability to overcome obstacles.

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