Walking mechanism and walking control method of tracked robot

Abstract

A walking mechanism of a crawler-type robot comprises a vehicle body and crawler-type walking mechanisms arranged on the two sides of the vehicle body, each crawler-type walking mechanism comprises a crawler belt, a wheel set and a swing arm assembly, and each wheel set comprises a driving wheel, a tensioning wheel, a towing wheel and a loading wheel; each loading wheel is connected with the vehicle body through a swing arm assembly, each swing arm assembly comprises a swing arm and a loading wheel control oil cylinder, one end of each swing arm is fixedly connected with a supporting shaft of the corresponding loading wheel, the other end of each swing arm is hinged to the vehicle body, one end of each loading wheel control oil cylinder is hinged to the vehicle body, and the other end of each loading wheel control oil cylinder is hinged to the middle section of the corresponding swing arm. The tensioning wheel is rotationally connected with the vehicle body through a tensioning wheel control oil cylinder, the loading wheel control oil cylinder and the tensioning wheel control oil cylinder are connected with a hydraulic control system through hydraulic oil pipes, the loading wheel and the tensioning wheel are displaced under the control of the hydraulic control system, and the walking posture of the tracked robot is changed.

Description

Technical Field

[0001] The present invention relates to the field of robot walking mechanisms, in particular to a walking mechanism and a walking control method of a crawler robot. Background Art

[0002] With the rapid development of social economy, mobile robots have been widely used in industry, agriculture and military fields. Tracked robots have become indispensable technical equipment in these fields due to their excellent terrain adaptability, good passing performance and high load capacity. However, tracked robots still have some shortcomings in practical applications and need to be improved.

[0003] The driving performance of a tracked robot is closely related to the coupling relationship between the track and the ground. The larger the contact area between the track and the ground, the greater the driving resistance, resulting in a decrease in the robot's acceleration ability and maximum speed. At the same time, the resistance during turning increases, the flexibility decreases, and the fuel or energy consumption also increases. However, increasing the contact area is conducive to improving the robot's carrying capacity and passing performance in complex terrain, so there are contradictory demands, and how to balance them becomes a technical difficulty.

[0004] CN216185575U discloses a crawler-type walking mechanism, which can achieve "load shock absorption through the cooperation of the supporting wheel group and the shock absorber with the suspension frame. The crawler is set on the outer periphery of the supporting wheel group, the driving wheel, the towing wheel group and the tensioning wheel, and is supported in a parallelogram shape, so that the crawler is more stable when walking. When encountering harsh terrain, there will be two extreme postures of forward tilt and backward overturning. Since the crawler in the shape of a parallelogram has a strong ability to pass through the terrain, when the body suddenly hits the bottom, the shock absorber can well resist the impact force and ensure safety, while improving the obstacle crossing ability and increasing the passability." This crawler-type walking mechanism, only through the movement of the tensioning wheel, makes the crawler present two extreme postures of forward tilt and backward overturning. The adjustment range of the crawler shape is limited, and only two postures of forward tilt and backward overturning are supported. It is impossible to achieve a large change in shape and it is difficult to meet the needs of diversified applications. The cooperation of the shock absorber and the suspension frame can only passively achieve the load shock absorption effect, and the shape of the crawler cannot be changed by active adjustment, thereby limiting the flexibility and adaptability of the robot. Summary of the invention

[0005] In order to solve the problems of the prior art, the present invention provides a walking mechanism of a tracked robot, wherein the road wheel group and the tensioner wheel of the walking mechanism of the tracked robot can move under the control of a hydraulic control system to actively change the shape of the track; the power assembly can move under the control of the hydraulic control system to actively change the center of mass of the tracked robot; the hydraulic control system can identify the operating state of the tracked robot and control the movement of the road wheel group, the tensioner wheel and the power assembly; when the tracked robot turns and runs at high speed, the walking posture of the walking mechanism is changed to improve the flexibility of the tracked robot, and the power performance such as acceleration and maximum speed and driving stability.

[0006] The technical solution of the present invention is achieved in this way: A walking mechanism of a crawler robot, comprising a vehicle body and a crawler walking mechanism arranged on both sides of the vehicle body, the crawler walking mechanism comprising a crawler, a wheel group, and a swing arm assembly, the wheel group comprising a driving wheel, a tensioning wheel, a traction wheel, and a road wheel, the driving wheel being arranged at the front end of the vehicle body and connected to a driving motor through a reduction mechanism, the driving motor being electrically connected to an energy storage battery, the tensioning wheel being arranged at the rear end of the vehicle body, a speed sensor being installed on the tensioning wheel, a plurality of traction wheels being arranged sequentially between the driving wheel and the tensioning wheel, and a plurality of road wheels being arranged sequentially below the vehicle body; each The road wheels are connected to the vehicle body through a swing arm assembly respectively, and the swing arm assembly includes a swing arm and a road wheel control cylinder. One end of the swing arm is fixedly connected to the supporting shaft of the road wheel, and the other end is hinged to the vehicle body. One end of the road wheel control cylinder is hinged to the vehicle body, and the other end is hinged to the middle section of the swing arm; the tensioner is rotatably connected to the vehicle body through the tensioner control cylinder, and the road wheel control cylinder and the tensioner control cylinder are both connected to the hydraulic control system through hydraulic oil pipes. Under the control of the hydraulic control system, the road wheels and the tensioner are displaced to change the walking posture of the crawler robot.

[0007] Preferably, the hydraulic control system includes a controller, a servo valve group, a hydraulic oil tank, and a hydraulic oil pipe. The controller is connected to the servo valve group and the oil pump in the hydraulic oil tank through wires. The hydraulic oil tank is connected to the road wheel control cylinder and the tensioner wheel control cylinder through the servo valve group and the hydraulic oil pipe respectively. The controller is connected to the speed sensor through wires.

[0008] Preferably, the energy storage battery and the generator are electrically connected to form a power assembly, and the power assembly is slidably engaged on a slide rail provided in the vehicle body through a slide seat provided thereon, and the power assembly is fixedly connected to a piston rod of a power assembly control cylinder provided in the vehicle body, and the power assembly control cylinder is connected to a hydraulic control system through a hydraulic oil pipe, so that the power assembly is axially displaced under the control of the hydraulic control system to change the center of mass position of the crawler robot.

[0009] Preferably, the tensioner wheel control cylinder is provided with a support seat for supporting the tensioner wheel axle, and the support seat is slidably fitted in a guide rail arranged on the outside of the vehicle body. A speed sensor is arranged on the support seat, and the speed sensor cooperates with the tensioner wheel axle to collect the running speed of the crawler walking mechanism.

[0010] A method for controlling a walking mechanism of a crawler robot comprises the following steps: S1: Set the speed difference threshold A of the tracks on both sides and the normal speed threshold B of the tracks in the controller; S2: Identify the running speed of the crawlers on both sides of the vehicle body through the speed sensors of the crawlers on both sides of the vehicle body; S3: Determine the running state of the crawler robot and change the walking posture and center of mass position of the crawler robot: When the measured running speed difference of the crawlers on both sides is less than the speed difference threshold A, and the running speeds of the crawlers on both sides of the vehicle body are less than the speed threshold B, the crawler robot is in a low-speed driving state, and the controller controls the walking posture and center of mass position of the crawler robot to maintain the initial state; When it is measured that the running directions of the tracks on both sides are opposite, the tracked robot is in the center turning state, and the controller controls the front road wheel control cylinder of the walking mechanism on one side of the tracked robot to contract and the rear road wheel control cylinder to extend, and the front road wheel control cylinder of the walking mechanism on the other side to extend and the rear road wheel control cylinder to contract, and the tension wheel active cylinders on both sides to extend, so that the tension wheel tightens the track, and the power assembly control cylinder drives the power assembly to move backward, so that the center of mass position of the tracked robot moves backward; When the running speed difference of the crawlers on both sides is measured to be greater than the speed difference threshold value A, the crawler robot is in a turning driving state, and the controller controls the front road wheel control cylinder of the walking mechanism on both sides of the crawler robot to contract, and the rear road wheel control cylinder to extend, and the tension wheel control cylinder to extend, so that the tension wheel tightens the crawler, and the power assembly control cylinder drives the power assembly to move backward, so that the center of mass position of the crawler robot moves backward; When the running speed difference of the crawlers on both sides is measured to be less than the speed difference threshold value A, and the running speeds of the crawlers on both sides of the vehicle body are greater than the speed threshold value B, the crawler robot is in a high-speed driving state, and the controller controls the front road wheel control cylinder of the walking mechanism on both sides of the crawler robot to contract, the rear road wheel control cylinder to extend, and the tension wheel control cylinder to extend, so that the tension wheel tightens the crawler track, and the power assembly control cylinder drives the power assembly to move the center of mass of the crawler robot backward; S4: After the state change of the crawler robot is completed, the controller controls the crawler robot to return to the state before the state change.

[0011] In summary, the present invention has the following advantages: 1. Actively change the walking posture of the walking mechanism according to the different operating states of the crawler robot; When driving at a low speed, the crawler robot maintains its initial state to ensure the load-bearing capacity and passability of the crawler robot; when turning at the center, the front road wheel control cylinder of the walking mechanism on one side of the crawler robot contracts, and the rear road wheel control cylinder extends, and the front road wheel control cylinder of the walking mechanism on the other side extends, and the rear road wheel control cylinder contracts, the tensioner control cylinder extends, and the powertrain control cylinder moves the center of mass of the vehicle backward, reducing the resistance of the vehicle when turning and enhancing the steering flexibility of the vehicle; when turning, the walking mechanisms on both sides of the crawler robot The front road wheel control cylinder of the mechanism contracts, the rear road wheel control cylinder extends, the tensioner control cylinder extends, and the powertrain control cylinder moves the vehicle's center of mass backward, reducing the resistance of the vehicle when turning and enhancing the vehicle's steering flexibility; when driving at high speed, the front road wheel control cylinder of the walking mechanism on both sides of the crawler robot contracts, the rear road wheel control cylinder extends, the tensioner control cylinder extends, and the powertrain control cylinder moves the vehicle's center of mass backward, reducing the crawler robot's driving resistance, increasing the grip of the rear road wheels, and enhancing the vehicle's dynamic performance.

[0012] 2. The hydraulic control system uses speed sensors installed on both sides of the vehicle body to identify the running speed of the tracks on both sides of the vehicle body, judge the running status of the crawler robot, and adjust the walking posture of the walking mechanism and the center of mass position of the crawler robot in real time. It does not require manual control, is easy to operate, and has a high degree of automation.

[0013] 3. The power assembly is connected to a power assembly control cylinder. When the crawler robot is running, the power assembly control cylinder drives the power assembly to slide along the axial direction of the vehicle body, thereby changing the center of mass position of the crawler robot, thereby enhancing the running stability of the crawler robot. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is the initial state of the walking posture of the present invention; Figure 2 It is the changed state of the walking posture of the present invention; Figure 3 It is a schematic flow chart of the control method of the present invention; Figure 4 is a schematic diagram of the effect of improving the power performance of an embodiment of the present invention; Figure 5 It is the relationship diagram between steering resistance torque and track ground contact length. DETAILED DESCRIPTION

[0015] See also Figures 1 to 3, a walking mechanism of a crawler robot, comprising a vehicle body 1, and a crawler walking mechanism arranged on both sides of the vehicle body, the crawler walking mechanism comprising a wheel group, a crawler 10 arranged on the periphery of the wheel group, and a swing arm assembly, the wheel group comprising a driving wheel 4, a tensioning wheel 6, a traction wheel 5, and a load wheel 3 rotatably connected to the vehicle body 1, the driving wheel 4 is arranged at the front end of the vehicle body 1, connected to the driving motor through a reduction mechanism, the driving motor is electrically connected to an energy storage battery, the tensioning wheel 6 is arranged at the rear end of the vehicle body, a speed sensor 12 is installed on the tensioning wheel 6, the traction wheel 5 is multiple, and is sequentially arranged between the driving wheel 4 and the tensioning wheel 6, the load wheel 3 is multiple, and is sequentially arranged below the vehicle body, in this embodiment, the number of traction wheels 5 of the walking mechanism of the crawler robot on one side of the vehicle body 1 is 3, and the number of load wheels 3 is 7; Each road wheel 3 is connected to the vehicle body through a swing arm assembly, and the swing arm assembly includes a swing arm 7 and a road wheel control cylinder 8. One end of the swing arm 7 is fixedly connected to the support shaft of the road wheel 3, and the other end is hinged to the vehicle body 1. One end of the road wheel control cylinder 8 is hinged to the vehicle body, and the other end is hinged to the middle section of the swing arm 7. The swing arm 7 is located in front of the road wheel control cylinder 8. The tensioner wheel 6 is rotatably connected to the vehicle body 1 through the tensioner wheel control cylinder 9. The tensioner wheel control cylinder 9 is provided with a support seat for supporting the wheel axle of the tensioner wheel 6. The support seat is slidably matched in the guide rail provided on the outside of the vehicle body 1. A speed sensor is provided on the support seat. The speed sensor cooperates with the wheel axle of the tensioner wheel 6 to collect the running speed of the crawler-type walking mechanism. The tensioner wheel control cylinder 9 can move axially along the vehicle body 1 to maintain the tension state of the crawler track, thereby avoiding the crawler track slippage caused by loose crawler track or uneven tension. The road wheel control cylinder 8 and the tension wheel control cylinder 9 are connected to the hydraulic control system through the hydraulic oil pipe 15, and the road wheel 3 and the tension wheel 6 are displaced under the control of the hydraulic control system to change the walking posture of the crawler robot; The hydraulic control system includes a controller 11, a servo valve group 13, a hydraulic oil tank 14, and a hydraulic oil pipe 15. The controller 11 is connected to the servo valve group 13 and the oil pump in the hydraulic oil tank 14 through a wire. The hydraulic oil tank 14 is connected to the road wheel control cylinder 8 and the tensioner wheel control cylinder 9 through the servo valve group 13 and the hydraulic oil pipe 15 respectively. The controller 11 is connected to the speed sensor 12 through a wire. The energy storage battery and the generator are electrically connected to form a power assembly 16. The power assembly 16 is slidably fitted on a slide rail provided in the vehicle body 1 through a slide seat provided thereon. The power assembly 16 is fixedly connected to a piston rod of a power assembly control cylinder 17 provided in the vehicle body 1. The power assembly control cylinder 17 is connected to a hydraulic control system through a hydraulic oil pipe 15. Under the control of the hydraulic control system, the power assembly 16 is axially displaced to change the center of mass position of the crawler robot.

[0016] The control method of the walking mechanism of the crawler robot comprises the following steps: S1: Set the speed difference threshold A of the tracks on both sides and the normal speed threshold B of the tracks in the controller; S2: Identify the running speed of the crawlers on both sides of the vehicle body through the speed sensors of the crawlers on both sides of the vehicle body; S3: Determine the running state of the crawler robot and change the walking posture and center of mass position of the crawler robot: When the measured running speed difference of the crawlers on both sides is less than the speed difference threshold A, and the running speeds of the crawlers on both sides of the vehicle body are less than the speed threshold B, the crawler robot is in a low-speed driving state, and the controller controls the walking posture and center of mass position of the crawler robot to maintain the initial state; When it is measured that the running directions of the crawlers on both sides are opposite, the crawler robot is in the center turning state, and the controller controls the front road wheel control cylinder 18 of the walking mechanism on one side of the crawler robot to contract and the rear road wheel control cylinder 19 to extend, and the front road wheel control cylinder 18 of the walking mechanism on the other side to extend and the rear road wheel control cylinder 19 to contract, and the tensioner active cylinders 9 on both sides to extend, so that the tensioner 6 tightens the crawler 10, and the power assembly control cylinder 17 drives the power assembly 16 to move backward, so that the center of mass position of the crawler robot moves backward; When the running speed difference of the crawlers on both sides is measured to be greater than the speed difference threshold value A, the crawler robot is in a turning driving state, and the controller controls the front road wheel control cylinder 18 of the walking mechanism on both sides of the crawler robot to contract, and the rear road wheel control cylinder 19 to extend, and the tensioner control cylinder 9 to extend, so that the tensioner 6 tightens the crawler 10, and the power assembly control cylinder 17 drives the power assembly 16 to move backward, so that the center of mass position of the crawler robot moves backward; When the running speed difference of the crawlers on both sides is measured to be less than the speed difference threshold value A, and the running speeds of the crawlers on both sides of the vehicle body are greater than the speed threshold value B, the crawler robot is in a high-speed driving state, and the controller controls the front road wheel control cylinder 18 of the walking mechanism on both sides of the crawler robot to contract, the rear road wheel control cylinder 19 to extend, and the tensioner control cylinder 9 to extend, so that the tensioner 6 tightens the crawler 10, and the power assembly control cylinder 17 drives the power assembly 16 to move the center of mass of the crawler robot backward; S4: After the state change of the crawler robot is completed, the controller controls the crawler robot to return to the state before the state change.

[0017] Working principle: In this embodiment, the front two road wheels 3 of the vehicle body 1 are the front road wheels 18, and the rear two road wheels 3 of the vehicle body 1 are the rear road wheels 19. In the turning driving state and the high-speed driving state, the road wheel control cylinder 8 connected to the front road wheel 18 contracts, thereby driving the front road wheel 18 to be lifted off the ground, and the road wheel control cylinder 8 connected to the rear road wheel 19 extends, increasing the grip of the rear road wheel 19, and the power assembly 16 moves to the rear side of the vehicle body 1, moving the center of mass of the crawler robot backward; Before the front road wheel 18 is lifted off the ground, the contact length between the crawler track 10 and the ground is 4000 mm. After the front road wheel 18 is lifted off the ground, the contact length between the crawler track 10 and the ground is 2900 mm.

[0018] To verify the beneficial effects of this embodiment, Figure 4 As shown, acceleration tests were performed on the contact lengths of the track 10 with the ground of 2900mm and 4000mm, and a comparison was made to obtain the speed-time curves of the two, wherein the red line represents the contact length of the track 10 with the ground of 2900mm, and the blue line represents the contact length of the track 10 with the ground of 4000mm. It can be seen that at nearly 7 seconds, the contact length of the track 10 with the ground of 2900mm is about 8% faster than the contact length of the track 10 with the ground of 4000mm, and the speed difference between the two gradually increases.

[0019] like Figure 5 As shown, when all other conditions are the same except for the different ground contact lengths, the tracked robot performs center steering, and the contact length of the track 10 with the ground is 2900 mm, compared with the contact length of the track 10 with the ground being 4000 mm, and the center steering resistance torque is 27.5% smaller.

[0020] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modification made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A walking mechanism of a crawler robot, comprising a body (1) and crawler walking mechanisms arranged on both sides of the body, characterized in that: The crawler-type walking mechanism comprises a crawler (10), a wheel group, and a swing arm assembly. The wheel group comprises a driving wheel (4), a tensioning wheel (6), a traction wheel (5), and a road wheel (3). The driving wheel (4) is arranged at the front end of the vehicle body (1) and is connected to a driving motor via a reduction mechanism. The driving motor is electrically connected to an energy storage battery. The tensioning wheel (6) is arranged at the rear end of the vehicle body. A speed sensor (12) is installed on the tensioning wheel (6). There are a plurality of traction wheels (5) which are arranged in sequence between the driving wheel (4) and the tensioning wheel (6). There are a plurality of road wheels (3) which are arranged in sequence below the vehicle body. Each road wheel (3) is connected to the vehicle body via a swing arm assembly. The swing arm assembly comprises a swing arm (7) and a road wheel control cylinder (8); one end of the swing arm (7) is fixedly connected to the support shaft of the road wheel (3), and the other end is hinged to the vehicle body (1); one end of the road wheel control cylinder (8) is hinged to the vehicle body, and the other end is hinged to the middle section of the swing arm (7); the tensioner (6) is rotatably connected to the vehicle body (1) via the tensioner control cylinder (9); the road wheel control cylinder (8) and the tensioner control cylinder (9) are both connected to a hydraulic control system via a hydraulic oil pipe (15); under the control of the hydraulic control system, the road wheel (3) and the tensioner (6) are displaced to change the walking posture of the crawler robot.

2. The walking mechanism of the crawler robot according to claim 1, characterized in that: The hydraulic control system comprises a controller (11), a servo valve group (13), a hydraulic oil tank (14), and a hydraulic oil pipe (15). The controller (11) is connected to the servo valve group (13) and an oil pump in the hydraulic oil tank (14) via a wire. The hydraulic oil tank (14) is connected to the road wheel control cylinder (8) and the tensioner wheel control cylinder (9) via the servo valve group (13) and the hydraulic oil pipe (15). The controller (11) is connected to the speed sensor (12) via a wire.

3. The walking mechanism of the crawler robot according to claim 1, characterized in that: The energy storage battery and the generator are electrically connected to form a power assembly (16); the power assembly (16) is slidably engaged on a slide rail provided in the vehicle body (1) via a slide seat provided thereon; the power assembly (16) is fixedly connected to a piston rod of a power assembly control cylinder (17) provided in the vehicle body (1); the power assembly control cylinder (17) is connected to a hydraulic control system via a hydraulic oil pipe (15); and under the control of the hydraulic control system, the power assembly (16) is axially displaced to change the center of mass position of the crawler robot.

4. The walking mechanism of the crawler robot according to claim 1, characterized in that: The tensioner wheel control oil cylinder (9) is provided with a support seat for supporting the wheel axle of the tensioner wheel (6), the support seat slidably engaged in a guide rail provided on the outside of the vehicle body (1), and a speed sensor is provided on the support seat, the speed sensor cooperates with the wheel axle of the tensioner wheel (6) to collect the running speed of the crawler walking mechanism.

5. The control method of the walking mechanism of a crawler robot according to claim 1, characterized in that: The following steps are involved: S1: Set the speed difference threshold A of the tracks on both sides and the normal speed threshold B of the tracks in the controller; S2: Identify the running speed of the crawlers on both sides of the vehicle body through the speed sensors of the crawlers on both sides of the vehicle body; S3: Determine the running state of the crawler robot and change the walking posture and center of mass position of the crawler robot: When the measured running speed difference of the crawlers on both sides is less than the speed difference threshold A, and the running speeds of the crawlers on both sides of the vehicle body are less than the speed threshold B, the crawler robot is in a low-speed driving state, and the controller controls the walking posture and center of mass position of the crawler robot to maintain the initial state; When it is measured that the running directions of the crawlers on both sides are opposite, the crawler robot is in a center turning state, and the controller controls the road wheel control cylinder (18) at the front of the walking mechanism on one side of the crawler robot to contract and the road wheel control cylinder (19) at the rear to extend, and the road wheel control cylinder (18) at the front of the walking mechanism on the other side to extend and the road wheel control cylinder (19) at the rear to contract, and the tension wheel active cylinders (9) on both sides to extend, so that the tension wheel (6) tightens the crawler (10), and the power assembly control cylinder (17) drives the power assembly (16) to move backward, so that the center of mass position of the crawler robot moves backward; When the measured running speed difference of the crawlers on both sides is greater than the speed difference threshold value A, the crawler robot is in a turning driving state, and the controller controls the front road wheel control cylinder (18) of the walking mechanism on both sides of the crawler robot to contract, and the rear road wheel control cylinder (19) to extend, and the tension wheel control cylinder (9) to extend, so that the tension wheel (6) tightens the crawler (10), and the power assembly control cylinder (17) drives the power assembly (16) to move backward, so that the center of mass position of the crawler robot moves backward; When the measured running speed difference of the crawlers on both sides is less than the speed difference threshold value A, and the running speeds of the crawlers on both sides of the vehicle body are greater than the speed threshold value B, the crawler robot is in a high-speed driving state, and the controller controls the front road wheel control cylinder (18) of the walking mechanism on both sides of the crawler robot to contract, the rear road wheel control cylinder (19) to extend, and the tension wheel control cylinder (9) to extend, so that the tension wheel (6) tightens the crawler (10), and the power assembly control cylinder (17) drives the power assembly (16) to move the center of mass of the crawler robot backward; S4: After the state change of the crawler robot is completed, the controller controls the crawler robot to return to the state before the state change.

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