Walking mechanism and walking control method of a tracked robot

Abstract

A walking mechanism of a tracked robot, comprising a vehicle body, and a tracked walking mechanism arranged on both sides of the vehicle body, the tracked walking mechanism comprising a track, a wheel set, a swing arm assembly, the wheel set comprising a driving wheel, a tensioning wheel, a trailing wheel, and a load wheel; each load wheel is connected to the vehicle body through a swing arm assembly, the swing arm assembly comprising a swing arm and a load wheel control cylinder, one end of the swing arm is fixedly connected to a supporting shaft of the load wheel, the other end is hingedly connected to the vehicle body, one end of the load wheel control cylinder is hingedly connected to the vehicle body, and the other end is hingedly connected to a middle section of the swing arm; the tensioning wheel is rotatably connected to the vehicle body through a tensioning wheel control cylinder, the load wheel control cylinder and the tensioning wheel control cylinder are connected to a hydraulic control system through hydraulic oil pipes, and the load wheel and the tensioning wheel are displaced under the control of the hydraulic control system to change the walking posture of the tracked robot.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robot walking mechanisms, in particular to a walking mechanism and a walking control method of a tracked robot. BACKGROUND

[0002] With the rapid development of social economy, mobile robots have been widely used in industrial, agricultural 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, there are still some deficiencies in the practical application of tracked robots, which 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 greater the contact area between the track and the ground, the greater the driving resistance, which leads to reduced acceleration ability and maximum speed of the robot, increased resistance during turning, decreased flexibility, and increased fuel or energy consumption. However, increasing the contact area is beneficial to improving the load capacity and passing performance of the robot in complex terrain, so there is a contradictory demand, and how to balance becomes a technical difficulty.

[0004] CN216185575U discloses a tracked walking mechanism that can achieve "load damping effect through the cooperation of the supporting wheel set, shock absorber and suspension bracket, the track is set on the outer periphery of the supporting wheel set, driving wheel, trailing wheel set and tensioning wheel, supporting a parallelogram shape, making the track more stable when walking, when encountering harsh terrain, there are two extreme postures of forward inclination and backward coverage, due to the strong terrain passing ability of the parallelogram-shaped track, when the machine body hits the bottom, the shock absorber can well resist the impact force, ensuring safety, and improving the obstacle crossing ability and passing performance." This tracked walking mechanism only adjusts the shape of the track through the movement of the tensioning wheel, and the track presents two extreme postures of forward inclination and backward coverage, the adjustment range of the track shape is limited, only supports two postures of forward inclination and backward coverage, and cannot realize large-scale shape change, which is difficult to meet the diversified application requirements. The cooperation of the shock absorber and the suspension bracket can only passively realize the load damping effect, and cannot change the shape of the track through active adjustment, thereby limiting the flexibility and adaptability of the robot. SUMMARY

[0005] To solve the problems of the prior art, the application provides a walking mechanism of a tracked robot, the walking mechanism of the tracked robot, a group of load wheels and a tensioner can move under the control of a hydraulic control system, and the shape of a track is actively changed; a power assembly can move under the control of the hydraulic control system, and the center of mass of the tracked robot is actively changed; the hydraulic control system can identify the running state of the tracked robot, and control the movement of the group of load wheels, the tensioner and the power assembly; when the tracked robot turns and runs at a high speed, the walking posture of the walking mechanism is changed, the flexibility of the tracked robot is improved, and the dynamic performance and driving stability such as acceleration and maximum speed are improved.

[0006] The technical scheme of the application is implemented as follows:

[0007] The walking mechanism of the tracked robot comprises a vehicle body and tracked walking mechanisms arranged on both sides of the vehicle body, the tracked walking mechanism comprises a track, a group of wheels and a swing arm assembly, the group of wheels comprises a driving wheel, a tensioner, a plurality of drag wheels and a plurality of load wheels, the driving wheel is arranged at the front end of the vehicle body and is connected to a driving motor through a speed reduction mechanism, the driving motor is electrically connected to an energy storage battery, the tensioner is arranged at the rear end of the vehicle body, a speed sensor is arranged on the tensioner, the plurality of drag wheels are arranged between the driving wheel and the tensioner in sequence, and the plurality of load wheels are arranged below the vehicle body in sequence; each load wheel is connected to the vehicle body through a swing arm assembly, the swing arm assembly comprises a swing arm and a load wheel control oil cylinder, one end of the swing arm is fixedly connected to a supporting shaft of the load wheel, the other end of the swing arm is hingedly connected to the vehicle body, one end of the load wheel control oil cylinder is hingedly connected to the vehicle body, and the other end of the load wheel control oil cylinder is hingedly connected to the middle segment of the swing arm; the tensioner is rotatably connected to the vehicle body through a tensioner control oil cylinder, and the load wheel control oil cylinder and the tensioner control oil cylinder are connected to a hydraulic control system through hydraulic oil pipes, so that the load wheels and the tensioner are displaced under the control of the hydraulic control system, and the walking posture of the tracked robot is changed.

[0008] Preferably, the hydraulic control system comprises a controller, a servo valve group, a hydraulic oil tank and an oil pump in the hydraulic oil tank, the controller is connected to the servo valve group and the oil pump through wires, the hydraulic oil tank is connected to the load wheel control oil cylinder and the tensioner control oil cylinder through the servo valve group and the hydraulic oil pipes, and the controller is connected to the speed sensor through wires.

[0009] Preferably, the energy storage battery and a generator are electrically connected to form a power assembly, the power assembly is slidably fitted on a slide rail arranged in the vehicle body through a slide base arranged on the power assembly, the power assembly is fixedly connected to a piston rod of a power assembly control oil cylinder arranged in the vehicle body, and the power assembly control oil cylinder is connected to the hydraulic control system through a hydraulic oil pipe, so that the power assembly is axially displaced under the control of the hydraulic control system, and the center of mass of the tracked robot is changed.

[0010] Preferably, the tensioning wheel control cylinder is provided with a support seat for supporting the tensioning wheel wheel shaft, which is slidingly fitted in a guide rail provided outside the vehicle body, and a speed sensor is provided on the support seat, which is fitted with the wheel shaft of the tensioning wheel and collects the running speed of the crawler track.

[0011] The control method of the walking mechanism of the crawler robot comprises the following steps:

[0012] S1: setting the speed difference threshold A of the two sides of the crawler belt and the crawler belt regular speed threshold B in the controller;

[0013] S2: identifying the running speed of the two sides of the crawler belt through the speed sensor of the two sides of the crawler belt of the vehicle body;

[0014] S3: judging the running state of the crawler robot and changing the walking posture and the center of mass position of the crawler robot:

[0015] When the running speed difference of the two sides of the crawler belt is less than the speed difference threshold A, and the running speed of the two sides of the vehicle body is less than the speed threshold B, the crawler robot is in a low-speed driving state, and the controller controls the walking posture and the center of mass position of the crawler robot to remain in the initial state;

[0016] When the running directions of the two sides of the crawler belt are opposite, the crawler robot is in a central turning state, the controller controls the front negative weight wheel control cylinder of one side of the walking mechanism to contract, the rear negative weight wheel control cylinder to elongate, the front negative weight wheel control cylinder of the other side of the walking mechanism to elongate, the rear negative weight wheel control cylinder to contract, the two sides of the tensioning wheel driving cylinder to elongate, so that the tensioning wheel tightens the crawler belt, 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;

[0017] When the running speed difference of the two sides of the crawler belt is greater than the speed difference threshold A, the crawler robot is in a turning driving state, the controller controls the front negative weight wheel control cylinder of the two sides of the walking mechanism to contract, the rear negative weight wheel control cylinder to elongate, the tensioning wheel control cylinder to elongate, so that the tensioning wheel tightens the crawler belt, 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;

[0018] When the running speed difference of the two sides of the crawler belt is less than the speed difference threshold A, and the running speed of the two sides of the vehicle body is greater than the speed threshold B, the crawler robot is in a high-speed driving state, the controller controls the front negative weight wheel control cylinder of the two sides of the walking mechanism to contract, the rear negative weight wheel control cylinder to elongate, the tensioning wheel control cylinder to elongate, so that the tensioning wheel tightens the crawler belt, and the power assembly control cylinder drives the power assembly, so that the center of mass position of the crawler robot moves backward;

[0019] S4: After the state change of the tracked robot ends, the controller controls the tracked robot to return to the state before the state change.

[0020] In summary, the present application has the following advantages:

[0021] 1. According to the different running states of the tracked robot, the walking posture of the walking mechanism is actively changed;

[0022] When driving at low speed, the tracked robot maintains the initial state to ensure the load capacity and passability of the tracked robot; when turning at the center, the front load wheel control cylinder of the walking mechanism on one side is retracted, the rear load wheel control cylinder is elongated, the front load wheel control cylinder of the walking mechanism on the other side is elongated, the rear load wheel control cylinder is retracted, the tensioner control cylinder is elongated, and the power assembly control cylinder moves the vehicle center of mass backward to reduce the resistance when the vehicle turns and enhance the turning flexibility of the vehicle; when driving at the center, the front load wheel control cylinder of the walking mechanism on both sides is retracted, the rear load wheel control cylinder is elongated, the tensioner control cylinder is elongated, and the power assembly control cylinder moves the vehicle center of mass backward to reduce the resistance when the vehicle turns and enhance the turning flexibility of the vehicle; when driving at high speed, the front load wheel control cylinder of the walking mechanism on both sides is retracted, the rear load wheel control cylinder is elongated, the tensioner control cylinder is elongated, and the power assembly control cylinder moves the vehicle center of mass backward to reduce the driving resistance of the tracked robot, increase the grip of the rear load wheel, and enhance the power performance of the vehicle.

[0023] 2. The hydraulic control system identifies the running speed of the tracks on both sides of the vehicle body through the speed sensors arranged on both sides of the vehicle body, judges the running state of the tracked robot, and adjusts the walking posture of the walking mechanism and the center of mass of the tracked robot in real time, without manual control, simple operation, and high automation.

[0024] 3. The power assembly is connected with a power assembly control cylinder, which drives the power assembly to slide along the vehicle body axis during the running of the tracked robot, changes the center of mass of the tracked robot, and enhances the running stability of the tracked robot. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is the initial state of the walking posture of the present application;

[0026] Figure 2 is the changed state of the walking posture of the present application;

[0027] Figure 3 is the control method flowchart of the present application;

[0028] Figure 4 is the power performance improvement effect diagram of the embodiment of the present application;

[0029] Figure 5 is a turning resistance torque and track ground length relationship diagram. DETAILED DESCRIPTION

[0030] Referring to Figures 1 to 3 A walking mechanism of a tracked robot, comprising a vehicle body 1 and a tracked walking mechanism arranged on both sides of the vehicle body, the tracked walking mechanism comprising a wheel set, a track 10 arranged on the outer periphery of the wheel set, and a swing arm assembly, the wheel set comprising a driving wheel 4 rotatably connected to the vehicle body 1, a tensioner 6, a plurality of tow wheels 5, and a plurality of load wheels 3, the driving wheel 4 being arranged at the front end of the vehicle body 1 and connected to a driving motor through a speed reduction mechanism, the driving motor being electrically connected to an energy storage battery, the tensioner 6 being arranged at the rear end of the vehicle body 1, a speed sensor 12 being arranged on the tensioner 6, the plurality of tow wheels 5 being arranged between the driving wheel 4 and the tensioner 6 in sequence, and the plurality of load wheels 3 being arranged below the vehicle body in sequence, in this embodiment, the number of tow wheels 5 of the walking mechanism of the tracked robot on one side of the vehicle body 1 is 3, and the number of load wheels 3 is 7;

[0031] Each load wheel 3 is connected to the vehicle body through a swing arm assembly, the swing arm assembly comprising a swing arm 7 and a load wheel control cylinder 8, one end of the swing arm 7 being fixedly connected to the support shaft of the load wheel 3, and the other end being hingedly connected to the vehicle body 1, one end of the load wheel control cylinder 8 being hingedly connected to the vehicle body, and the other end being hingedly connected to the middle section of the swing arm 7, the swing arm 7 being located in front of the load wheel control cylinder 8;

[0032] The tensioner 6 is rotatably connected to the vehicle body 1 through a tensioner control cylinder 9, the tensioner control cylinder 9 being provided with a support seat for supporting the wheel shaft of the tensioner 6, the support seat being slidingly fitted in a guide rail arranged on the outer side of the vehicle body 1, the support seat being provided with a speed sensor, the speed sensor being matched with the wheel shaft of the tensioner 6 to collect the running speed of the tracked walking mechanism, and the tensioner control cylinder 9 being axially movable along the vehicle body 1 to maintain the tensioning state of the track and avoid the track slipping due to slackness or uneven tension;

[0033] The load wheel control cylinder 8 and the tensioner control cylinder 9 are connected to a hydraulic control system through a hydraulic oil pipe 15, and the load wheel 3 and the tensioner 6 are displaced under the control of the hydraulic control system to change the walking posture of the tracked robot;

[0034] 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 being connected to the servo valve group 13 and an oil pump in the hydraulic oil tank 14 through wires, the hydraulic oil tank 14 being connected to the load wheel control cylinder 8 and the tensioner control cylinder 9 through the servo valve group 13 and the hydraulic oil pipe 15, and the controller 11 being connected to the speed sensor 12 through wires.

[0035] The energy storage battery is electrically connected with the generator to form a power assembly 16, the power assembly 16 is slidably matched on a slide rail arranged in the vehicle body 1 through a slide arranged on the power assembly 16, the power assembly 16 is fixedly connected with a power assembly control oil cylinder 17 arranged in the vehicle body 1 through a piston rod, the power assembly control oil cylinder 17 is connected with a hydraulic control system through a hydraulic oil pipe 15, and the power assembly 16 is axially displaced under the control of the hydraulic control system to change the centroid position of the tracked robot.

[0036] The control method of the tracked robot comprises the following steps:

[0037] S1: setting a speed difference threshold A of the two sides of the tracked robot and a speed threshold B of the tracked robot in a controller;

[0038] S2: identifying the running speed of the two sides of the tracked robot through a speed sensor arranged on the two sides of the tracked robot;

[0039] S3: judging the running state of the tracked robot and changing the walking posture and the centroid position of the tracked robot:

[0040] When the running speed difference of the two sides of the tracked robot is less than the speed difference threshold A and the running speed of the two sides of the tracked robot is less than the speed threshold B, the tracked robot is in a low-speed running state, and the controller controls the walking posture and the centroid position of the tracked robot to keep the initial state;

[0041] When the running directions of the two sides of the tracked robot are opposite, the tracked robot is in a central turning state, the controller controls the front negative load wheel control oil cylinder 18 of one walking mechanism of the tracked robot to contract, the rear negative load wheel control oil cylinder 19 of one walking mechanism of the tracked robot to elongate, the front negative load wheel control oil cylinder 18 of the other walking mechanism of the tracked robot to elongate, the rear negative load wheel control oil cylinder 19 of the other walking mechanism of the tracked robot to contract, the two sides of the tensioning wheel driving oil cylinder 9 to elongate, the tensioning wheel 6 to tighten the track 10, and the power assembly control oil cylinder 17 to drive the power assembly 16 to move backward, so that the centroid position of the tracked robot moves backward;

[0042] When the running speed difference of the two sides of the tracked robot is greater than the speed difference threshold A, the tracked robot is in a turning running state, the controller controls the front negative load wheel control oil cylinder 18 of the two sides of the tracked robot to contract, the rear negative load wheel control oil cylinder 19 of the two sides of the tracked robot to elongate, the tensioning wheel control oil cylinder 9 to elongate, the tensioning wheel 6 to tighten the track 10, and the power assembly control oil cylinder 17 to drive the power assembly 16 to move backward, so that the centroid position of the tracked robot moves backward;

[0043] When the speed difference of the two sides of the track is less than the speed difference threshold A, and the running speed of the two sides of the track is greater than the speed threshold B, the track robot is in a high-speed running state, and the controller controls the front bogie control cylinder 18 of the track robot to retract, the rear bogie control cylinder 19 to extend, and the tensioning wheel control cylinder 9 to extend, so that the tensioning wheel 6 tightens the track 10, and the power assembly control cylinder 17 drives the power assembly 16, so that the center of mass of the track robot moves backward.

[0044] S4: After the state of the track robot changes, the controller controls the track robot to return to the state before the state changes.

[0045] Working principle:

[0046] In this embodiment, the front two bogies 3 of the vehicle body 1 are front bogies 18, and the rear two bogies 3 of the vehicle body 1 are rear bogies 19. In the steering running state and the high-speed running state, the front bogie control cylinder 8 connected to the front bogie 18 retracts, thereby driving the front bogie 18 to lift off the ground. The rear bogie control cylinder 8 connected to the rear bogie 19 extends, increasing the grip of the rear bogie 19. The power assembly 16 moves to the rear side of the vehicle body 1, moving the center of mass of the track robot backward.

[0047] Before the front bogie 18 lifts off the ground, the contact length of the track 10 with the ground is 4000mm. After the front bogie 18 lifts off the ground, the contact length of the track 10 with the ground is 2900mm.

[0048] To verify the beneficial effects of this embodiment, as shown in Figure 4 The acceleration tests of the contact length of the track 10 with the ground being 2900mm and the contact length of the track 10 with the ground being 4000mm are compared, and the speed-time curves of the two are obtained. The red line represents the contact length of the track 10 with the ground being 2900mm, and the blue line represents the contact length of the track 10 with the ground being 4000mm. Therefore, at about 7 seconds, the contact length of the track 10 with the ground being 2900mm is about 8% faster than the contact length of the track 10 with the ground being 4000mm, and the speed difference between the two gradually increases.

[0049] As shown in Figure 5 Under the condition that the contact length of the track 10 with the ground is different, and the remaining conditions are the same, the track robot performs center steering. The contact length of the track 10 with the ground being 2900mm is 27.5% smaller than the contact length of the track 10 with the ground being 4000mm in terms of center steering torque.

[0050] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modification made by those skilled in the art without departing from the spirit of the present application falls within the scope of protection of the present application.

Claims

1. A control method of a walking mechanism of a tracked robot, the tracked robot comprising a vehicle body (1), and a tracked walking mechanism arranged on both sides of the vehicle body, the tracked walking mechanism comprising a track (10), a wheel set, a swing arm assembly, the wheel set comprising a driving wheel (4), a tension wheel (6), a drag wheel (5), and a load wheel (3), the driving wheel (4) being arranged at a front end of the vehicle body (1), connected to a driving motor through a speed reduction mechanism, the driving motor being electrically connected to an energy storage battery, the energy storage battery being electrically connected to a generator to form a power assembly (16), the power assembly (16) being fixedly connected to a piston rod of a power assembly control cylinder (17) arranged in the vehicle body (1), the tension wheel (6) being arranged at a rear end of the vehicle body, a speed sensor (12) being arranged on the tension wheel (6), the drag wheel (5) being a plurality of, arranged between the driving wheel (4) and the tension wheel (6) in sequence, the load wheel (3) being a plurality of, arranged below the vehicle body in sequence, each load wheel (3) being connected to the vehicle body through a swing arm assembly, the swing arm assembly comprising a swing arm (7) and a load wheel control cylinder (8), one end of the swing arm (7) being fixedly connected to a support shaft of the load wheel (3), the other end being hingedly connected to the vehicle body (1), one end of the load wheel control cylinder (8) being hingedly connected to the vehicle body, the other end being hingedly connected to a middle section of the swing arm (7), the tension wheel (6) being rotatably connected to the vehicle body (1) through a tension wheel control cylinder (9), the load wheel control cylinder (8) and the tension wheel control cylinder (9) being connected to a hydraulic control system through a hydraulic oil pipe (15), the hydraulic control system comprising a controller (11), under the control of the hydraulic control system, the load wheel (3) and the tension wheel (6) are displaced to change the walking posture of the tracked robot; characterized in that: The method comprises the following steps: S1: setting a speed difference threshold A of the two sides of the track and a track normal speed threshold B in the controller; S2: identifying the running speed of the two sides of the track through the speed sensor of the two sides of the track; S3: judging the running state of the tracked robot and changing the walking posture and the center of mass position of the tracked robot: When the running speed difference of the two sides of the track is less than the speed difference threshold A and the running speed of the two sides of the track is less than the speed threshold B, the tracked robot is in a low-speed running state, and the controller controls the walking posture and the center of mass position of the tracked robot to remain in the initial state; When the running directions of the two sides of the track are opposite, the tracked robot is in a central turning state, the controller controls the front load wheel control cylinder (18) of one walking mechanism to contract, the rear load wheel control cylinder (19) to elongate, the front load wheel control cylinder (18) of the other walking mechanism to elongate, the rear load wheel control cylinder (19) to contract, the two sides of the tensioning wheel control cylinder (9) to elongate, the tensioning wheel (6) to tighten the track (10), and the power assembly control cylinder (17) to drive the power assembly (16) to move backward, so that the center of mass position of the tracked robot moves backward; When the running speed difference of the two sides of the track is greater than the speed difference threshold A, the tracked robot is in a turning running state, the controller controls the front load wheel control cylinder (18) of the two sides of the walking mechanism to contract, the rear load wheel control cylinder (19) to elongate, the tensioning wheel control cylinder (9) to elongate, the tensioning wheel (6) to tighten the track (10), and the power assembly control cylinder (17) to drive the power assembly (16) to move backward, so that the center of mass position of the tracked robot moves backward; When the running speed difference of the two sides of the track is less than the speed difference threshold A and the running speed of the two sides of the track is greater than the speed threshold B, the tracked robot is in a high-speed running state, the controller controls the front load wheel control cylinder (18) of the two sides of the walking mechanism to contract, the rear load wheel control cylinder (19) to elongate, the tensioning wheel control cylinder (9) to elongate, the tensioning wheel (6) to tighten the track (10), and the power assembly control cylinder (17) to drive the power assembly (16), so that the center of mass position of the tracked robot moves backward; S4: after the state of the tracked robot changes, the controller controls the tracked robot to return to the state before the state changes.

2. The method of controlling the traveling mechanism of the track robot according to claim 1, characterized by: 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 with the servo valve group (13) and an oil pump in the hydraulic oil tank (14) through wires, the hydraulic oil tank (14) is connected with the load wheel control cylinder (8) and the tensioning wheel control cylinder (9) through the servo valve group (13) and the hydraulic oil pipe (15), and the controller (11) is connected with the speed sensor (12) through wires.

3. The method of claim 1, wherein: The power assembly (16) is slidably fitted on the slide rail arranged in the vehicle body (1) through the slide arranged thereon, the power assembly control oil cylinder (17) is connected with the hydraulic control system through the hydraulic oil pipe (15), and the power assembly (16) is axially displaced under the control of the hydraulic control system, so that the centroid position of the tracked robot is changed.

4. The method of controlling the traveling mechanism of the track robot according to claim 1, characterized by: The supporting seat for supporting the wheel shaft of the tensioning wheel (6) is arranged on the tensioning wheel control oil cylinder (9) and is slidably fitted in the guide rail arranged outside the vehicle body (1), and the speed sensor is arranged on the supporting seat and cooperates with the wheel shaft of the tensioning wheel (6) to collect the running speed of the tracked walking mechanism.

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