18-axis 6-leg constant tension walking motion control system and method

Abstract

The present invention provides an 18-axis, 6-leg constant-tension walking motion control system and method. The system includes a body, six leg structures, a motion control unit, and a motion controller. The six leg structures include leg structure 1, leg structure 2, leg structure 3, leg structure 4, leg structure 5, and leg structure 6. The six leg structures are identical, and any leg structure includes a hip joint, thigh, knee joint, calf, and foot. The 18-axis, 6-leg constant-tension walking motion control system provided by the present invention has two sets of leg structures, each set of leg structures including three legs arranged in a triangle. Therefore, when one set of leg structures is airborne, the other set of leg structures generates a forward-driving tendency while remaining grounded, thereby achieving triangular stable support and improving walking stability.

Description

Technical Field

[0001] The present invention belongs to the technical field of walking motion control, and in particular relates to an 18-axis 6-leg constant tension walking motion control system and method. Background Art

[0002] With the development of automation technology, various types of robots are being used more and more widely, especially in high-risk and harsh environments, where robots play a huge role.

[0003] During use, due to the harsh working environment and other reasons, conventional robots are only equipped with two legs, which has the problem of low walking stability. Summary of the Invention

[0004] In view of the defects of the existing technology, the present invention provides an 18-axis 6-leg constant tension walking motion control system and method, which can effectively solve the above problems.

[0005] The technical solution adopted in the present invention is as follows:

[0006] The present invention provides an 18-axis 6-leg constant tension walking motion control system, comprising a body, 6 leg structures, a motion control unit, and a motion controller; the 6 leg structures include leg structure No. 1, leg structure No. 2, leg structure No. 3, leg structure No. 4, leg structure No. 5, and leg structure No. 6;

[0007] The fuselage body is a rectangular structure, and the No. 4 leg structure, the No. 2 leg structure, and the No. 6 leg structure are respectively installed at the left front end, the left middle part, and the left rear end of the fuselage body; the No. 1 leg structure, the No. 5 leg structure, and the No. 3 leg structure are respectively installed at the right front end, the right middle part, and the right rear end of the fuselage body;

[0008] The left and right direction of the fuselage body is the Y-axis direction, the front and back direction is the X-axis direction, and the vertical direction is the Z-axis direction, and an XYZ coordinate system is established;

[0009] The six leg structures are all identical, and any leg structure includes a hip joint, a thigh, a knee joint, a calf, and a sole; the hip joint is connected to the body; the top of the thigh is connected to the hip joint, and the bottom of the thigh and the top of the calf are connected via the knee joint; the bottom of the calf is connected to the sole; the hip joint is provided with a hip joint X-axis rotation axis and a hip joint Y-axis rotation axis; the knee joint is provided with a knee joint Y-axis rotation axis; and a three-dimensional force sensor is installed in the sole of the foot;

[0010] Each leg structure is equipped with three motion control units, namely: hip joint X-axis motion control unit, hip joint Y-axis motion control unit and knee joint Y-axis motion control unit;

[0011] The motion controller is connected to the hip joint X-axis rotation axis through the hip joint X-axis motion control unit; the motion controller is connected to the hip joint Y-axis rotation axis through the hip joint Y-axis motion control unit; the motion controller is connected to the knee joint Y-axis rotation axis through the knee joint Y-axis motion control unit;

[0012] An input end of the motion controller is connected to the three-dimensional force sensor.

[0013] Preferably, the three-dimensional force sensor includes a lateral force sensor along the Y-axis direction, a driving force sensor along the X-axis direction, and a vertical ground force sensor along the Z-axis direction.

[0014] Preferably, the hip joint X-axis motion control unit includes: a hip joint X-axis rotation driver, a hip joint X-axis rotation servo motor, a hip joint X-axis PID controller, a hip joint X-axis regulator, a hip joint X-axis position encoder, and a hip joint X-axis speed position given value;

[0015] The motion controller outputs the hip joint X-axis speed position given value to the positive input end of the hip joint X-axis regulator; the output of the lateral force sensor along the Y-axis direction is connected to the negative input end of the hip joint X-axis regulator; the output of the hip joint X-axis position encoder is connected to the negative input end of the hip joint X-axis regulator; the hip joint X-axis regulator outputs a control signal, which passes through the hip joint X-axis PID controller, the hip joint X-axis rotation driver and the hip joint X-axis rotation servo motor in sequence, and acts on the hip joint X-axis rotation axis to achieve control of the hip joint X-axis rotation axis.

[0016] Preferably, the hip joint Y-axis motion control unit includes: a hip joint Y-axis rotation driver, a hip joint Y-axis rotation servo motor, a hip joint Y-axis PID controller, a hip joint Y-axis regulator, a hip joint Y-axis position encoder, and a hip joint Y-axis speed position given value;

[0017] The motion controller outputs the hip joint Y-axis speed position given value to the positive input end of the hip joint Y-axis regulator; the output of the driving force sensor along the X-axis direction is connected to the negative input end of the hip joint Y-axis regulator; the output of the hip joint Y-axis position encoder is connected to the negative input end of the hip joint Y-axis regulator; the hip joint Y-axis regulator outputs a control signal, which passes through the hip joint Y-axis PID controller, the hip joint Y-axis rotation driver and the hip joint Y-axis rotation servo motor in sequence, and acts on the hip joint Y-axis rotation axis to achieve control of the hip joint Y-axis rotation axis.

[0018] Preferably, the knee joint Y-axis motion control unit includes: a knee joint Y-axis rotation driver, a knee joint Y-axis rotation servo motor, a knee joint Y-axis PID controller, a knee joint Y-axis regulator, a knee joint Y-axis position encoder, and a knee joint Y-axis speed and position given value;

[0019] The motion controller outputs the knee joint Y-axis speed position given value to the positive input end of the knee joint Y-axis regulator; the output of the driving force sensor along the X-axis direction and the output of the vertical ground force sensor along the Z-axis direction are both connected to the negative input end of the knee joint Y-axis regulator; the output of the knee joint Y-axis position encoder is connected to the negative input end of the knee joint Y-axis regulator; the knee joint Y-axis regulator outputs a control signal, which passes through the knee joint Y-axis PID controller, the knee joint Y-axis rotation driver and the knee joint Y-axis rotation servo motor in sequence, and acts on the knee joint Y-axis rotation axis to achieve control of the knee joint Y-axis rotation axis.

[0020] Preferably, the fuselage body is equipped with a gyroscope, an acceleration sensor, a camera sensor and a level sensor;

[0021] The motion controller is connected to the gyroscope, the acceleration sensor, the camera sensor and the level sensor respectively.

[0022] The present invention also provides a control method for an 18-axis 6-leg constant tension walking motion control system, comprising the following steps:

[0023] Step 1: After the system is powered on, it will self-check and then return the six legs to their original default positions;

[0024] Step 2: The motion controller collects the Y-axis lateral force, X-axis driving force, and Z-axis vertical ground force of each leg in real time;

[0025] Then, the motion controller sends control instructions to the six legs in an isochronous and synchronous manner according to the current action to be completed; the control instructions include the hip joint X-axis rotation angle, the hip joint Y-axis rotation angle, and the knee joint Y-axis rotation angle;

[0026] Each leg performs corresponding actions according to the control instructions it receives.

[0027] Preferably, in step 2, the walking action is performed using the following method:

[0028] Step 2.1, leg structure No. 1, leg structure No. 2, and leg structure No. 3 form a first group of leg structures; leg structure No. 4, leg structure No. 5, and leg structure No. 6 form a second group of leg structures;

[0029] Step 2.2, two-stage control:

[0030] In the first stage of control, the six legs jointly generate a forward driving force along the X-axis:

[0031] The motion controller uses three-dimensional force sensors installed on each leg to detect in real time the current resultant force of the six legs' driving forces along the X-axis, namely, the foot friction force along the X-axis. Based on the current resultant force, the motion controller adjusts the knee and hip joint angles of each leg in the first leg structure, thereby adjusting the driving force along the X-axis of each leg in the first leg structure. This driving force along the X-axis drives each leg in the first leg structure to lift its foot and take a step forward at a certain stride length and speed.

[0032] In the second stage of control, each leg in the second group of leg structures provides driving force along the X-axis:

[0033] The motion controller adjusts the knee and hip joint angles of each leg in the second leg structure according to the resultant force, thereby adjusting the driving force of each leg in the second leg structure along the X-axis, so that each leg in the second leg structure has a forward driving tendency but does not leave the ground; at this time, leg structures No. 4, No. 5, and No. 6 in the second leg structure form a triangular stable support structure; at this time, each leg in the first leg structure is in a forward-leaping state;

[0034] Step 2.3, two-stage control:

[0035] In the first stage of control, the six legs jointly generate a forward driving force along the X-axis:

[0036] When each leg of the first set of leg structures is detected to have landed, the motion controller uses the three-dimensional force sensors installed on each leg to detect in real time the current resultant force of the six legs' driving forces along the X-axis, i.e., the foot friction force along the X-axis. Based on the current resultant force, the motion controller adjusts the knee and hip joint angles of each leg in the second set of leg structures, thereby adjusting the driving force along the X-axis of each leg in the second set of leg structures. This driving force along the X-axis is used to drive each leg in the second set of leg structures to lift its foot and take a step forward at a certain stride length and speed.

[0037] In the second stage of control, each leg in the first group of leg structures provides driving force along the X-axis:

[0038] The motion controller adjusts the knee and hip joint angles of each leg in the first leg structure according to the resultant force, thereby adjusting the driving force of each leg in the first leg structure along the X-axis, so that each leg in the first leg structure has a forward driving tendency but does not leave the ground; at this time, leg structure No. 1, leg structure No. 2, and leg structure No. 3 in the first leg structure form a triangular stable support structure; at this time, each leg in the second leg structure is in a forward-leaping state;

[0039] Repeat steps 2.2 and 2.3 to achieve walking.

[0040] Preferably, in step 2, the following method is used to perform constant tension walking motion control:

[0041] The system adjusts each leg simultaneously in any permutation and combination. For any leg, the adjustment method is:

[0042] A three-dimensional force sensor installed in the sole of a leg can simultaneously detect the Y-axis lateral force, X-axis driving force and Z-axis vertical ground force of a leg;

[0043] If the leg is not within the constant tension range, adjust its Y-axis lateral force, X-axis driving force, and Z-axis vertical ground force respectively to keep it within the constant tension range;

[0044] Among them: the method for adjusting the lateral force in the Y-axis direction is: adjusting it by the hip joint rotating around the X-axis driver; the method for adjusting the driving force in the X-axis direction is: adjusting the hip joint rotating around the Y-axis driver and the knee joint rotating around the Y-axis driver at the same time; the method for adjusting the vertical ground force in the Z-axis direction is: adjusting it by the knee joint rotating around the Y-axis driver.

[0045] The 18-axis 6-leg constant tension walking motion control system and method provided by the present invention has the following advantages:

[0046] The 18-axis, 6-leg constant-tension walking motion control system provided by the present invention has two groups of leg structures, each of which includes three legs arranged in a triangle. Therefore, when one group of leg structures is in the air, the other group of leg structures produces a forward driving tendency but does not leave the ground, thereby achieving triangular stable support and improving walking stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the structure of the 18-axis 6-leg constant tension walking motion control system provided by the present invention;

[0048] Figure 2 This is a schematic diagram of the 18-axis, 6-leg constant-tension walking motion control system provided by the present invention. DETAILED DESCRIPTION

[0049] In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0050] refer to Figure 1 and Figure 2The present invention provides an 18-axis 6-leg constant tension walking motion control system, comprising a body, 6 leg structures, a motion control unit, and a motion controller; the 6 leg structures include leg structure No. 1, leg structure No. 2, leg structure No. 3, leg structure No. 4, leg structure No. 5, and leg structure No. 6;

[0051] The fuselage body is a rectangular structure, and the No. 4 leg structure, the No. 2 leg structure, and the No. 6 leg structure are respectively installed at the left front end, the left middle part, and the left rear end of the fuselage body; the No. 1 leg structure, the No. 5 leg structure, and the No. 3 leg structure are respectively installed at the right front end, the right middle part, and the right rear end of the fuselage body;

[0052] The left and right direction of the fuselage body is the Y-axis direction, the front and back direction is the X-axis direction, and the vertical direction is the Z-axis direction, and an XYZ coordinate system is established;

[0053] The six leg structures are all identical, and any leg structure includes a hip joint, a thigh, a knee joint, a calf, and a sole; the hip joint is connected to the body; the top of the thigh is connected to the hip joint, and the bottom of the thigh and the top of the calf are connected via the knee joint; the bottom of the calf is connected to the sole; the hip joint is provided with a hip joint X-axis rotation axis and a hip joint Y-axis rotation axis; the knee joint is provided with a knee joint Y-axis rotation axis; and a three-dimensional force sensor is installed in the sole of the foot;

[0054] Each leg structure is equipped with three motion control units, namely: hip joint X-axis motion control unit, hip joint Y-axis motion control unit and knee joint Y-axis motion control unit.

[0055] The motion controller is connected to the hip joint X-axis rotation axis via the hip joint X-axis motion control unit; the motion controller is connected to the hip joint Y-axis rotation axis via the hip joint Y-axis motion control unit; the motion controller is connected to the knee joint Y-axis rotation axis via the knee joint Y-axis motion control unit; the input end of the motion controller is connected to the three-dimensional force sensor. The three-dimensional force sensor includes a lateral force sensor along the Y-axis direction, a driving force sensor along the X-axis direction, and a vertical ground force sensor along the Z-axis direction.

[0056] The specific structures of the hip joint X-axis motion control unit, hip joint Y-axis motion control unit and knee joint Y-axis motion control unit are:

[0057] (1) Hip joint X-axis motion control unit

[0058] In specific implementation, the hip joint X-axis motion control unit includes: a hip joint X-axis rotation driver, a hip joint X-axis rotation servo motor, a hip joint X-axis PID controller, a hip joint X-axis regulator, a hip joint X-axis position encoder, and a hip joint X-axis speed position given value;

[0059] The motion controller outputs the hip joint X-axis speed position given value to the positive input end of the hip joint X-axis regulator; the output of the lateral force sensor along the Y-axis direction is connected to the negative input end of the hip joint X-axis regulator; the output of the hip joint X-axis position encoder is connected to the negative input end of the hip joint X-axis regulator; the hip joint X-axis regulator outputs a control signal, which passes through the hip joint X-axis PID controller, the hip joint X-axis rotation driver and the hip joint X-axis rotation servo motor in sequence, and acts on the hip joint X-axis rotation axis to achieve control of the hip joint X-axis rotation axis.

[0060] (2) Hip joint Y-axis motion control unit

[0061] The hip joint Y-axis motion control unit includes: a hip joint Y-axis rotation driver, a hip joint Y-axis rotation servo motor, a hip joint Y-axis PID controller, a hip joint Y-axis regulator, a hip joint Y-axis position encoder, and a hip joint Y-axis speed position given value;

[0062] The motion controller outputs the hip joint Y-axis speed position given value to the positive input end of the hip joint Y-axis regulator; the output of the driving force sensor along the X-axis direction is connected to the negative input end of the hip joint Y-axis regulator; the output of the hip joint Y-axis position encoder is connected to the negative input end of the hip joint Y-axis regulator; the hip joint Y-axis regulator outputs a control signal, which passes through the hip joint Y-axis PID controller, the hip joint Y-axis rotation driver and the hip joint Y-axis rotation servo motor in sequence, and acts on the hip joint Y-axis rotation axis to achieve control of the hip joint Y-axis rotation axis.

[0063] (3) Knee joint Y-axis motion control unit

[0064] The knee joint Y-axis motion control unit includes: a knee joint Y-axis rotation driver, a knee joint Y-axis rotation servo motor, a knee joint Y-axis PID controller, a knee joint Y-axis regulator, a knee joint Y-axis position encoder, and a knee joint Y-axis speed and position given value;

[0065] The motion controller outputs the knee joint Y-axis speed position given value to the positive input end of the knee joint Y-axis regulator; the output of the driving force sensor along the X-axis direction and the output of the vertical ground force sensor along the Z-axis direction are both connected to the negative input end of the knee joint Y-axis regulator; the output of the knee joint Y-axis position encoder is connected to the negative input end of the knee joint Y-axis regulator; the knee joint Y-axis regulator outputs a control signal, which passes through the knee joint Y-axis PID controller, the knee joint Y-axis rotation driver and the knee joint Y-axis rotation servo motor in sequence, and acts on the knee joint Y-axis rotation axis to achieve control of the knee joint Y-axis rotation axis.

[0066] Furthermore, in the present invention, the body is equipped with a gyroscope, an acceleration sensor, a camera sensor, and a level sensor; the motion controller is connected to the gyroscope, the acceleration sensor, the camera sensor, and the level sensor, respectively. These sensors are directly connected to the motion controller, and the movement of each leg is controlled by a functional expression corresponding to each leg.

[0067] The present invention provides a control method for an 18-axis 6-leg constant tension walking motion control system, comprising the following steps:

[0068] Step 1: After the system is powered on, it will self-check. After the self-check passes, the six legs will return to their original default positions to prepare for exercise.

[0069] Step 2: The motion controller collects the Y-axis lateral force, X-axis driving force, and Z-axis vertical ground force of each leg in real time;

[0070] Then, the motion controller sends control instructions to the six legs in an isochronous and synchronous manner according to the current action to be completed; the control instructions include the X-axis rotation angle of the hip joint, the Y-axis rotation angle of the hip joint, and the Y-axis rotation angle of the knee joint; each leg performs the corresponding action according to the received control instructions.

[0071] Specifically, the following method is used to perform the walking action:

[0072] Step 2.1, leg structure No. 1, leg structure No. 2, and leg structure No. 3 form a first group of leg structures; leg structure No. 4, leg structure No. 5, and leg structure No. 6 form a second group of leg structures;

[0073] Step 2.2, two-stage control:

[0074] In the first stage of control, the six legs jointly generate a forward driving force along the X-axis:

[0075] The motion controller uses three-dimensional force sensors installed on each leg to detect in real time the current resultant force of the six legs' driving forces along the X-axis, namely, the foot friction force along the X-axis. Based on the current resultant force, the motion controller adjusts the knee and hip joint angles of each leg in the first leg structure, thereby adjusting the driving force along the X-axis of each leg in the first leg structure. This driving force along the X-axis drives each leg in the first leg structure to lift its foot and take a step forward at a certain stride length and speed.

[0076] In the second stage of control, each leg in the second group of leg structures provides driving force along the X-axis:

[0077] The motion controller adjusts the knee and hip joint angles of each leg in the second leg structure according to the resultant force, thereby adjusting the driving force of each leg in the second leg structure along the X-axis, so that each leg in the second leg structure has a forward driving tendency but does not leave the ground; at this time, leg structures No. 4, No. 5, and No. 6 in the second leg structure form a triangular stable support structure; at this time, each leg in the first leg structure is in a forward-leaping state;

[0078] Step 2.3, two-stage control:

[0079] In the first stage of control, the six legs jointly generate a forward driving force along the X-axis:

[0080] When each leg of the first set of leg structures is detected to have landed, the motion controller uses the three-dimensional force sensors installed on each leg to detect in real time the current resultant force of the six legs' driving forces along the X-axis, i.e., the foot friction force along the X-axis. Based on the current resultant force, the motion controller adjusts the knee and hip joint angles of each leg in the second set of leg structures, thereby adjusting the driving force along the X-axis of each leg in the second set of leg structures. This driving force along the X-axis is used to drive each leg in the second set of leg structures to lift its foot and take a step forward at a certain stride length and speed.

[0081] In the second stage of control, each leg in the first group of leg structures provides driving force along the X-axis:

[0082] The motion controller adjusts the knee and hip joint angles of each leg in the first leg structure according to the resultant force, thereby adjusting the driving force of each leg in the first leg structure along the X-axis, so that each leg in the first leg structure has a forward driving tendency but does not leave the ground; at this time, leg structure No. 1, leg structure No. 2, and leg structure No. 3 in the first leg structure form a triangular stable support structure; at this time, each leg in the second leg structure is in a forward-leaping state;

[0083] Repeat steps 2.2 and 2.3 to complete the walking action.

[0084] In addition, in the present invention, the following method is used to perform constant tension walking motion control:

[0085] The system adjusts each leg simultaneously in any permutation and combination. For any leg, the adjustment method is:

[0086] A three-dimensional force sensor installed in the sole of a leg can simultaneously detect the Y-axis lateral force, X-axis driving force and Z-axis vertical ground force of a leg;

[0087] If the leg is not within the constant tension range, adjust its Y-axis lateral force, X-axis driving force, and Z-axis vertical ground force respectively to keep it within the constant tension range;

[0088] Among them: the method for adjusting the lateral force in the Y-axis direction is: adjusting it by the hip joint rotating around the X-axis driver; the method for adjusting the driving force in the X-axis direction is: adjusting the hip joint rotating around the Y-axis driver and the knee joint rotating around the Y-axis driver at the same time; the method for adjusting the vertical ground force in the Z-axis direction is: adjusting it by the knee joint rotating around the Y-axis driver.

[0089] An embodiment is described below:

[0090] The system consists of a total of 6 legs, each leg consists of a hip joint (the direction is rotation around the X-axis, driven by a servo motor), a hip joint (the direction is rotation around the Y-axis, driven by a servo motor), a thigh, a knee joint (the direction is rotation around the Y-axis, driven by a servo motor), a calf, and a foot (with an embedded three-dimensional force sensor).

[0091] Hip joints: The system includes 12 hip joints, divided into two groups of six. One group of hip joints (rotates around the X-axis and is driven by a servo motor) is oriented left and right, that is, along the Y-axis. The other group of hip joints (rotates around the Y-axis and is driven by a servo motor) is oriented forward and backward, that is, along the X-axis.

[0092] Knee joint: The system includes 6 knee joints, which are driven by servo motors and automatically adjust the angle dynamically according to demand.

[0093] Sole of foot: A three-dimensional force sensor is embedded in the sole of the foot to detect forces in the X-axis, Y-axis, and Z-axis directions.

[0094] In the present invention, the entire control system is centered on a motion controller. After receiving an instruction, the system simultaneously adjusts the movements of the six legs according to the instruction. The virtual axis gives commands to the six legs simultaneously using different functions in an isochronous and synchronous manner according to the movements that the six legs need to complete. Each leg automatically adjusts the rotation angle of each joint of each leg (driven by a servo motor) based on an acceleration sensor, (front, rear, left, right, up, and down camera sensors), a gyroscope, a level sensor, and a three-dimensional force sensor installed on the sole of each leg (real-time detection of the contact force between the leg and the ground in three directions: x-axis, y-axis, and z-axis).

[0095] Specifically, the six legs move simultaneously, with the hip joints of legs 1#2#3# (the direction is rotation around the Y axis, driven by a servo motor) rotating at the same angle, and the knee joints (the direction is rotation around the Y axis, driven by a servo motor) rotating at the same angle, achieving the effect of taking off.

[0096] While legs 1#2#3# are moving, legs 4#5#6# are also moving at the same time. The hip joints of legs 4#5#6# (the direction is rotation around the Y axis, driven by servo motors) rotate at the same angle, and the knee joints rotate at the same angle. However, in terms of effect, the movements are slower than those of legs 1#2#3#. Moreover, legs 4#5#6# are always in contact with the ground before legs 1#2#3# touch the ground, and the force of the contact is detected by the 3D force sensors installed on the soles of legs 4#5#6#.

[0097] Therefore, the force provided in the direction of movement is divided into two stages. The first stage is the resultant force of the pedaling forces of legs 1#2#3#4#5#6# (that is, the force driving the entire object in the direction of movement along the X-axis). The force on the X-axis of the three-dimensional force sensor embedded in the sole of the foot detects the force of each leg in the direction of movement and provides real-time feedback to the system. The system automatically adjusts to provide a short-term pedaling force when legs 1#2#3# are not off the ground; the second stage is the resultant force of the pedaling forces of legs 4#5#6# (that is, the force driving the entire object in the direction of movement along the X-axis). At this time, legs 1#2#3# are completely off the ground. When legs 4#5#6# reach the predetermined position, legs 1#2#3# are completely on the ground at the same time; then legs 4#5#6# start to take off again, entering a new round of repetitive movements.

[0098] The 18-axis 6-leg constant tension walking motion control system and method provided by the present invention has the following advantages:

[0099] The 18-axis, 6-leg constant-tension walking motion control system provided by the present invention has two groups of leg structures, each of which includes three legs arranged in a triangle. Therefore, when one group of leg structures is in the air, the other group of leg structures produces a forward driving tendency but does not leave the ground, thereby achieving triangular stable support and improving walking stability.

[0100] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for an 18-axis 6-leg constant tension walking motion control system, characterized in that: The 18-axis 6-leg constant tension walking motion control system includes a body, 6 leg structures, a motion control unit and a motion controller; the 6 leg structures include leg structure No. 1, leg structure No. 2, leg structure No. 3, leg structure No. 4, leg structure No. 5 and leg structure No. 6; The fuselage body is a rectangular structure, and the No. 4 leg structure, the No. 2 leg structure, and the No. 6 leg structure are respectively installed at the left front end, the left middle part, and the left rear end of the fuselage body; the No. 1 leg structure, the No. 5 leg structure, and the No. 3 leg structure are respectively installed at the right front end, the right middle part, and the right rear end of the fuselage body; The left and right direction of the fuselage body is the Y-axis direction, the front and back direction is the X-axis direction, and the vertical direction is the Z-axis direction, and an XYZ coordinate system is established; The six leg structures are all identical, and any leg structure includes a hip joint, a thigh, a knee joint, a calf, and a sole; the hip joint is connected to the body; the top of the thigh is connected to the hip joint, and the bottom of the thigh and the top of the calf are connected via the knee joint; the bottom of the calf is connected to the sole; the hip joint is provided with a hip joint X-axis rotation axis and a hip joint Y-axis rotation axis; the knee joint is provided with a knee joint Y-axis rotation axis; and a three-dimensional force sensor is installed in the sole of the foot; Each leg structure is equipped with three motion control units, namely: hip joint X-axis motion control unit, hip joint Y-axis motion control unit and knee joint Y-axis motion control unit; The motion controller is connected to the hip joint X-axis rotation axis through the hip joint X-axis motion control unit; the motion controller is connected to the hip joint Y-axis rotation axis through the hip joint Y-axis motion control unit; the motion controller is connected to the knee joint Y-axis rotation axis through the knee joint Y-axis motion control unit; The input end of the motion controller is connected to the three-dimensional force sensor; The control method includes the following steps: Step 1: After the system is powered on, it will self-check and then return the six legs to their original default positions; Step 2: The motion controller collects the Y-axis lateral force, X-axis driving force, and Z-axis vertical ground force of each leg in real time; Then, the motion controller sends control instructions to the six legs in an isochronous and synchronous manner according to the current action to be completed; the control instructions include the hip joint X-axis rotation angle, the hip joint Y-axis rotation angle, and the knee joint Y-axis rotation angle; Each leg performs corresponding actions according to the control instructions received; In step 2, perform the walking action using the following method: Step 2.1, leg structure No. 1, leg structure No. 2, and leg structure No. 3 form a first group of leg structures; leg structure No. 4, leg structure No. 5, and leg structure No. 6 form a second group of leg structures; Step 2.2, two-stage control: In the first stage of control, the six legs jointly generate a forward driving force along the X-axis: The motion controller uses three-dimensional force sensors installed on each leg to detect in real time the current resultant force of the six legs' driving forces along the X-axis, namely, the foot friction force along the X-axis. Based on the current resultant force, the motion controller adjusts the knee and hip joint angles of each leg in the first leg structure, thereby adjusting the driving force along the X-axis of each leg in the first leg structure. This driving force along the X-axis drives each leg in the first leg structure to lift its foot and take a step forward at a certain stride length and speed. In the second stage of control, each leg in the second group of leg structures provides driving force along the X-axis: The motion controller adjusts the knee and hip joint angles of each leg in the second leg structure according to the resultant force, thereby adjusting the driving force of each leg in the second leg structure along the X-axis, so that each leg in the second leg structure has a forward driving tendency but does not leave the ground; at this time, leg structures No. 4, No. 5, and No. 6 in the second leg structure form a triangular stable support structure; at this time, each leg in the first leg structure is in a forward-leaping state; Step 2.3, two-stage control: In the first stage of control, the six legs jointly generate a forward driving force along the X-axis: When each leg of the first set of leg structures is detected to have landed, the motion controller uses the three-dimensional force sensors installed on each leg to detect in real time the current resultant force of the six legs' driving forces along the X-axis, i.e., the foot friction force along the X-axis. Based on the current resultant force, the motion controller adjusts the knee and hip joint angles of each leg in the second set of leg structures, thereby adjusting the driving force along the X-axis of each leg in the second set of leg structures. This driving force along the X-axis is used to drive each leg in the second set of leg structures to lift its foot and take a step forward at a certain stride length and speed. In the second stage of control, each leg in the first group of leg structures provides driving force along the X-axis: The motion controller adjusts the knee and hip joint angles of each leg in the first leg structure according to the resultant force, thereby adjusting the driving force of each leg in the first leg structure along the X-axis, so that each leg in the first leg structure has a forward driving tendency but does not leave the ground; at this time, leg structure No. 1, leg structure No. 2, and leg structure No. 3 in the first leg structure form a triangular stable support structure; at this time, each leg in the second leg structure is in a forward-leaping state; Repeat steps 2.2 and 2.3 to achieve walking action; In step 2, the following method is used to control the constant tension walking motion: The system adjusts each leg simultaneously in any permutation and combination. For any leg, the adjustment method is: A three-dimensional force sensor installed in the sole of a leg can simultaneously detect the Y-axis lateral force, X-axis driving force and Z-axis vertical ground force of a leg; If the leg is not within the constant tension range, adjust its Y-axis lateral force, X-axis driving force, and Z-axis vertical ground force respectively to keep it within the constant tension range; Among them: the method for adjusting the lateral force in the Y-axis direction is: adjusting it by the hip joint rotating around the X-axis driver; the method for adjusting the driving force in the X-axis direction is: adjusting the hip joint rotating around the Y-axis driver and the knee joint rotating around the Y-axis driver at the same time; the method for adjusting the vertical ground force in the Z-axis direction is: adjusting it by the knee joint rotating around the Y-axis driver.

2. The control method of the 18-axis 6-leg constant tension walking motion control system according to claim 1 is characterized in that: The three-dimensional force sensor includes a lateral force sensor along the Y-axis direction, a driving force sensor along the X-axis direction, and a vertical ground force sensor along the Z-axis direction.

3. The control method of the 18-axis 6-leg constant tension walking motion control system according to claim 2 is characterized in that: The hip joint X-axis motion control unit includes: a hip joint X-axis rotation driver, a hip joint X-axis rotation servo motor, a hip joint X-axis PID controller, a hip joint X-axis regulator, a hip joint X-axis position encoder, and a hip joint X-axis speed position given value; The motion controller outputs the hip joint X-axis speed position given value to the positive input end of the hip joint X-axis regulator; the output of the lateral force sensor along the Y-axis direction is connected to the negative input end of the hip joint X-axis regulator; the output of the hip joint X-axis position encoder is connected to the negative input end of the hip joint X-axis regulator; the hip joint X-axis regulator outputs a control signal, which passes through the hip joint X-axis PID controller, the hip joint X-axis rotation driver and the hip joint X-axis rotation servo motor in sequence, and acts on the hip joint X-axis rotation axis to achieve control of the hip joint X-axis rotation axis.

4. The control method of the 18-axis 6-leg constant tension walking motion control system according to claim 2 is characterized in that: The hip joint Y-axis motion control unit includes: a hip joint Y-axis rotation driver, a hip joint Y-axis rotation servo motor, a hip joint Y-axis PID controller, a hip joint Y-axis regulator, a hip joint Y-axis position encoder, and a hip joint Y-axis speed position given value; The motion controller outputs the hip joint Y-axis speed position given value to the positive input end of the hip joint Y-axis regulator; the output of the driving force sensor along the X-axis direction is connected to the negative input end of the hip joint Y-axis regulator; the output of the hip joint Y-axis position encoder is connected to the negative input end of the hip joint Y-axis regulator; the hip joint Y-axis regulator outputs a control signal, which passes through the hip joint Y-axis PID controller, the hip joint Y-axis rotation driver and the hip joint Y-axis rotation servo motor in sequence, and acts on the hip joint Y-axis rotation axis to achieve control of the hip joint Y-axis rotation axis.

5. The control method of the 18-axis 6-leg constant tension walking motion control system according to claim 2, characterized in that: The knee joint Y-axis motion control unit includes: a knee joint Y-axis rotation driver, a knee joint Y-axis rotation servo motor, a knee joint Y-axis PID controller, a knee joint Y-axis regulator, a knee joint Y-axis position encoder, and a knee joint Y-axis speed and position given value; The motion controller outputs the knee joint Y-axis speed position given value to the positive input end of the knee joint Y-axis regulator; the output of the driving force sensor along the X-axis direction and the output of the vertical ground force sensor along the Z-axis direction are both connected to the negative input end of the knee joint Y-axis regulator; the output of the knee joint Y-axis position encoder is connected to the negative input end of the knee joint Y-axis regulator; the knee joint Y-axis regulator outputs a control signal, which passes through the knee joint Y-axis PID controller, the knee joint Y-axis rotation driver and the knee joint Y-axis rotation servo motor in sequence, and acts on the knee joint Y-axis rotation axis to achieve control of the knee joint Y-axis rotation axis.

6. The control method of the 18-axis 6-leg constant tension walking motion control system according to claim 1 is characterized in that: The fuselage body is equipped with a gyroscope, an acceleration sensor, a camera sensor and a level sensor; The motion controller is connected to the gyroscope, the acceleration sensor, the camera sensor and the level sensor respectively.

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