A system and method for controlling a mobile platform using a two-foot coordination

Abstract

The application discloses a system and method for controlling a mobile platform by using two feet, comprising a motion capture positioning point, a throttle pedal, a positioner, an upper computer, and a mobile platform; a robot operator wears the motion capture positioning point on the left foot, and steps on the throttle pedal with the right foot; the positioner is placed around the operator to ensure that the motion capture positioning point is within the detection range; motion capture data of the two feet are collected and input into the upper computer; after being solved into a speed instruction, the speed instruction is transmitted to the mobile platform; the operator controls the movement of the robot mobile platform by means of the cooperation of the left and right feet, can control the mobile platform by using two legs, and can adjust the mapping ratio in real time, so that the fast movement and the fine movement are taken into account.

Description

Technical Field

[0001] This invention belongs to the technical field of robotics, specifically relating to a system and method for controlling a mobile platform using both feet in coordination. Background Technology

[0002] With technological advancements, humanoid robots with human-like arms and hands are expected to leverage human-like dexterity in many fields, including home service, industrial production, military, and aerospace, thereby assisting or replacing humans in performing tedious, dangerous, and complex tasks. In particular, they could replace humans in dangerous environments such as space exploration, deep-sea exploration, and disaster relief to complete complex tasks on the front lines. However, due to current technological limitations, humanoid robots cannot yet achieve fully autonomous operation. Planning the tasks and trajectories of humanoid robots through remote control via human-in-the-loop remains the most feasible solution in the short term.

[0003] Based on the upper limbs of humanoid robots, the lower limbs can take various forms depending on the terrain, such as legs, tracks, wheels, etc. In most cases, their movement can be regarded as a planar rigid body with a maximum of 3 degrees of freedom.

[0004] Therefore, to control the movement of a humanoid robot mobile platform on the ground, traditional teleoperation methods typically use joystick control, mapping the angular displacement of the joystick in a certain direction to a velocity command for one of the three degrees of freedom. However, this method occupies both hands, which is only suitable for controlling the mobile platform. Since teleoperation of the humanoid robot's arms and hands also requires real-time control, this method cannot achieve coordinated control of the mobile platform and the arms and hands, thus having certain limitations.

[0005] To solve this problem, the control of the mobile platform is changed to use the legs or feet, so that the mobile platform and the arms and hands can be controlled simultaneously. Existing technologies mainly include omnidirectional treadmills and omnidirectional foot pedals.

[0006] Omnidirectional treadmills can intuitively map the direction of a human operator's running to the speed command of the robot's mobile platform. The disadvantage is that during the mobile operation, the person always needs to stand, and for long-term mobile operations, the person needs to move on the treadmill, which consumes a lot of physical strength.

[0007] The omnidirectional foot pedal is a 3-DOF (degrees of freedom) reset joystick that can be stepped on. The deflection angle of the foot pedal can be mapped to the speed command of the moving platform. It can be operated while seated without the need for the operator to run. The disadvantage is that when performing lateral translation and rotational combined movements, the foot pedal posture is relatively tiring, and it is difficult to adjust the mapping ratio in real time, thus making it difficult to balance rapid and precise movements. Summary of the Invention

[0008] In view of this, the present invention provides a system and method for controlling a mobile platform using both feet, which can control the mobile platform using both legs and can adjust the mapping ratio in real time, thereby taking into account both rapid movement and precise movement.

[0009] The technical solution for implementing the present invention is as follows:

[0010] A system for controlling a mobile platform using both feet includes a motion capture positioning point, an accelerator pedal, a positioning device, a host computer, and a mobile platform;

[0011] The robot operator wears a motion capture positioning point on their left foot and presses the accelerator pedal with their right foot. Positioners are placed around the operator to ensure that the motion capture positioning point is within their detection range. The motion capture data of both feet is collected and input into the host computer, which calculates it into speed commands and then transmits them to the mobile platform. The operator controls the movement of the robot mobile platform by coordinating their left and right feet.

[0012] A method for controlling a mobile platform using both feet includes the following steps:

[0013] Step 1: Use motion capture equipment to collect foot movements to calculate foot pose, using the accelerator pedal as the algorithm activation and proportional mapping device;

[0014] Step 2: Transmit the foot motion data and accelerator pedal depth data to the host computer for motion calculation, which is then converted into speed commands and transmitted to the robot's mobile platform.

[0015] Furthermore, the operator wears a motion capture positioning point on their left foot and uses a locator to collect the spatial pose of the motion capture positioning point, thereby knowing the pose of the left foot on the ground as x, y, θ (x and y are planar position coordinates, and θ is the angle of rotation around the z-axis); the operator presses the accelerator pedal with their right foot to control the accelerator pedal depth k; the pose of the left foot on the ground and the accelerator pedal depth controlled by the right foot are transmitted to the host computer, which maps them into speed commands for the mobile platform, and finally sends the speed commands to the mobile platform of the humanoid robot.

[0016] Furthermore, the mapping method is as follows:

[0017] (1) Set the accelerator pedal depth response threshold to k0. When the accelerator pedal depth k≤k0, the mapping algorithm is invalid; when the accelerator pedal depth k>k0, the mapping algorithm is effective. Record the left foot pose at this time and set it as the initial pose x0, y0, θ0.

[0018] (2) When controlling the robot to move, the left foot slides out in the direction of the desired platform movement, so that the left foot pose deviates from the initial position. The current pose is recorded as x1, y1, θ1.

[0019] (3) Controlling the movement of the mobile platform requires three speed commands, v x vy ω z According to the formula:

[0020] v x = (k-k0)*(x1-x0)

[0021] v y = (k-k0)*(y1-y0)

[0022] ω z = (k-k0)*(θ1-θ0).

[0023] Furthermore, when the mobile platform needs to stop moving, simply release the accelerator pedal; at this point, the mapping algorithm fails, and the speed in all directions is reset to zero.

[0024] Beneficial effects:

[0025] Compared with existing technologies:

[0026] (1) The speed mapping ratio can be easily adjusted by the accelerator pedal, taking into account both fast and fine movement, and releasing the pedal can achieve emergency stop.

[0027] (2) The direction of foot sliding is consistent with the direction of platform speed, which is highly intuitive, can improve operation efficiency, and has low training cost.

[0028] (3) Based on the 3-degree-of-freedom offset of the foot from the initial position as the basic velocity command, the position of the legs and feet can be unrestricted, and a natural and comfortable placement range can be found. Compared with existing technologies, this can effectively reduce fatigue. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the system of the present invention that utilizes the cooperation of both feet to control a mobile platform.

[0030] Figure 2 This is a schematic diagram of the mapping algorithm of the present invention.

[0031] Among them, 1-motion capture positioning point, 2-throttle pedal, 3-positioner, 4-host computer, 5-mobile platform. Detailed Implementation

[0032] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] This invention provides a system for controlling a mobile platform using both feet. For example... Figure 1 The control system consists of a motion capture positioning point 1, an accelerator pedal 2, a positioner 3, a host computer 4, and a mobile platform 5.

[0034] The robot operator wears a motion capture positioning point 1 on his left foot and presses the accelerator pedal 2 with his right foot. The positioning device 3 is placed around the operator to ensure that the positioning point 1 is within its detection range. The collected motion capture data is connected to the host computer 4, calculated into speed commands, and then transmitted to the mobile platform 5. The operator controls the movement of the robot mobile platform by coordinating his left and right feet.

[0035] The specific technical solution of the method of the present invention is as follows:

[0036] The operator wears a motion capture positioning point on their left foot. A locator is used to acquire the spatial pose of this point, thus determining the left foot's pose on the ground: x, y, θ (x and y are planar coordinates, and θ is the angle of rotation around the z-axis). The operator's right foot depresses the accelerator pedal, controlling the pedal depth k. The left foot's pose on the ground and the accelerator pedal depth controlled by the right foot are transmitted to the host computer, which maps them into speed commands for the mobile platform. Finally, the speed commands are sent to the humanoid robot's mobile platform.

[0037] The specific mapping method is as follows: Figure 2 As shown:

[0038] (1) Set the accelerator pedal depth response threshold to k0. When the accelerator pedal depth k≤k0, let k=k0, the mapping algorithm is invalid. When the accelerator pedal depth k>k0, the mapping algorithm takes effect. Record the left foot pose at this time and set it as the initial pose x0, y0, θ0.

[0039] (2) When controlling the robot to move, the left foot slides out in the direction of the desired platform movement, so that the left foot pose deviates from the initial position. The current pose is recorded as x1, y1, θ1.

[0040] (3) Controlling the movement of the mobile platform requires three speed commands, v x v y ω z According to the formula:

[0041] v x = (k-k0)*(X1-X0)

[0042] v y = (k-k0)*(Y1-Y0)

[0043] ω z = (k-k0)*(θ1-θ0)

[0044] Calculate the three speed commands. Determine the response method for the three speed commands based on the specific form of the robot's mobile platform.

[0045] For example, omnidirectional mobile platforms such as Mecanum wheels and legged systems can... y The response is the forward and backward movement speed, v xThe response is the lateral velocity, ω. z The response is the steering speed, and general motion is the combination of these three factors.

[0046] For example, the Ekman steering platform can... y The response is the forward and backward movement speed, for v x No response, ω z The response is the steering mechanism angle.

[0047] Based on the above mapping method, the operator can first lightly press the accelerator pedal beyond the threshold, and then slide the left foot to control the robot's movement. Provided the accelerator pedal exceeds the threshold, and the left foot's position remains unchanged after sliding, the deeper the accelerator pedal is pressed, the faster the platform moves in all directions; conversely, if the accelerator pedal depth remains constant, the farther the left foot slides relative to the initial position, the faster the platform moves. Thus, the moving platform can be controlled by coordinating the left and right feet.

[0048] When the platform needs to stop moving, simply release the accelerator pedal. At this point, the mapping algorithm becomes ineffective, the velocity in all directions is reset to zero, and the left foot can move freely. The next time the accelerator pedal is pressed, a new initial pose of the left foot will be recorded, eliminating the need to find the previous initial position.

[0049] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling a mobile platform using both feet, the method being applied to a system for controlling a mobile platform using both feet, the system comprising a motion capture positioning point, an accelerator pedal, a positioning device, a host computer, and a mobile platform; The robot operator wears a motion capture positioning point on his left foot and presses the accelerator pedal with his right foot. Positioners are placed around the operator to ensure that the motion capture positioning point is within its detection range. The motion capture data of the two feet is collected and input into the host computer, which calculates it into speed commands and then transmits them to the mobile platform. The operator controls the movement of the robot mobile platform by coordinating the left and right feet. Its features are, Includes the following steps: Step 1: Use motion capture equipment to collect foot movements to calculate foot pose, using the accelerator pedal as the algorithm activation and proportional mapping device; Step 2: Transmit the foot motion data and accelerator pedal depth data to the host computer for motion calculation, convert the calculated speed command into a speed command, and then transmit it to the robot's mobile platform. The operator wears a motion capture positioning point on their left foot and uses a locator to collect the spatial pose of the motion capture positioning point, thereby knowing the pose of the left foot on the ground (x, y, θ); the operator presses the accelerator pedal with their right foot to control the accelerator pedal depth (k); the pose of the left foot on the ground and the accelerator pedal depth controlled by the right foot are transmitted to the host computer, which maps them into speed commands for the mobile platform, and finally sends the speed commands to the mobile platform of the humanoid robot. The mapping method is as follows: (1) Set the accelerator pedal depth response threshold to k0. When the accelerator pedal depth k≤k0, the mapping algorithm is invalid; when the accelerator pedal depth k>k0, the mapping algorithm is effective. Record the left foot pose at this time and set it as the initial pose x0, y0, θ0. (2) When controlling the robot to move, the left foot slides out in the direction of the desired platform movement, so that the left foot pose deviates from the initial position. The current pose is recorded as x1, y1, θ1. (3) Controlling the movement of the mobile platform requires three speed commands, v x v y ω z According to the formula: v x =(k-k0)*(x1-x0) v y =(k-k0)*(y1-y0) oh z =(k-k0)*(θ1-θ0).

2. The method as described in claim 1, characterized in that, When the mobile platform needs to stop moving, simply release the accelerator pedal. At this time, the mapping algorithm fails and the speed in all directions is reset to zero.

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