A hybrid drive power-assisted exoskeleton device and method

Abstract

The present invention discloses a hybrid drive power-assisted exoskeleton device and method, which relates to the technical field of power-assisted robots, including a hip joint module and a sensor assembly, wherein the hip joint module is rotatably connected to both sides of the back body, the hip joint module is connected to a pneumatic artificial muscle and a joint motor, and the pneumatic artificial muscle and the joint motor are connected to a control assembly; the sensor assembly includes a pressure sensor, an inclination sensor, and a gyroscope, wherein the pressure sensor is used to obtain the state of the pneumatic artificial muscle, and the inclination sensor and the gyroscope are used to detect the inclination angle, so that the control assembly controls the pneumatic artificial muscle or the joint motor to work according to the inclination angle of the human body. The present invention adopts pneumatic drive when extracting and putting down objects, and adopts motor drive during walking and carrying objects, so as to improve the object carrying efficiency and extend the service life of the device.

Description

Technical Field

[0001] The present invention relates to the technical field of power-assisted robots, and in particular to a hybrid-driven power-assisted exoskeleton device and method. Background Art

[0002] At present, most of the power-assisted exoskeletons are single-driven, such as only choosing motor drive, hydraulic drive or pneumatic muscle drive. The application scenarios and power-assisted range of single drive are limited, and the exoskeleton-assisted operation cannot be fully and efficiently completed. When only pneumatic muscle drive is used, since the pneumatic system requires a continuous supply of air, if the air supply is insufficient, it may affect the normal operation of the exoskeleton; the precision control of air drive is relatively difficult, which will cause the movement during the handling process to be imprecise; in addition, the response speed of air drive is slow, which will affect the performance of some handling tasks that require quick response. When only driven by a motor, the motor has high energy consumption in some cases, especially when continuous high-power output is required, the battery life may be short, and frequent charging or battery replacement is required, affecting convenience, etc.

[0003] Since the working principles and response characteristics of motors and pneumatic artificial muscles are different, more complex regulation is required to coordinate the actions of the two to ensure the stability and safety of the system. The reliability of electric and pneumatic systems is different, and the failure of any part may affect the overall performance. Therefore, it is difficult to mix motors and pneumatic artificial muscles to drive the power assist device. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a hybrid drive assisted exoskeleton device and method, which adopts pneumatic drive when picking up and putting down objects, and adopts motor drive during walking and carrying objects, so as to improve the object carrying efficiency and extend the service life of the device.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] In a first aspect, an embodiment of the present invention provides a hybrid drive power-assisted exoskeleton device, comprising:

[0007] A hip joint module is rotatably connected to both sides of the back body, the hip joint module is connected to the pneumatic artificial muscle and the joint motor, and the pneumatic artificial muscle and the joint motor are connected to the control component;

[0008] The sensor component includes a pressure sensor, an inclination sensor, and a gyroscope. The pressure sensor is used to obtain the state of the pneumatic artificial muscle, and the inclination sensor and the gyroscope are used to detect the inclination angle so that the control component can control the pneumatic artificial muscle or joint motor to work according to the inclination angle of the human body.

[0009] As a further implementation, the control component includes an MCU microcontroller and a PLC controller. The MCU microcontroller is used to receive detection signals from a gyroscope and an inclination sensor and transmit the signals to the PLC controller. The PLC controller is used to control the pneumatic artificial muscle.

[0010] As a further implementation, the back body is connected to an arm strap, and the arm strap is equipped with a position sensor; the position sensor is used to detect and measure the position of an object.

[0011] As a further implementation, the sensor assembly further includes an angular velocity sensor, and the angular velocity sensor is used to detect the angular velocity of the hip joint module.

[0012] As a further implementation, the joint motor is installed with a motor encoder, and the motor encoder is used to obtain the position and speed of the joint motor.

[0013] In a second aspect, an embodiment of the present invention further provides a control method for a hybrid drive power-assisted exoskeleton device, comprising:

[0014] Whether the tilt angle is within a threshold range is determined based on the detection signals of the gyroscope and the inclination sensor. When the tilt angle is within the threshold range, it is considered as a squatting and lifting or squatting and lowering action, and the pneumatic artificial muscle drives the hip joint module to move; when the tilt angle is not within the threshold range, it is considered as a moving action for carrying an object, and the joint motor drives the hip joint module to move.

[0015] As a further implementation manner, a position sensor is used in advance to detect and measure the position of the object.

[0016] As a further implementation method, the joint motor adopts PID control to generate a control signal according to the target position and the current position; the pneumatic artificial muscle adopts MPC model predictive control to generate an air pressure control signal according to the target state and the current state.

[0017] As a further implementation, the joint motor and the pneumatic artificial muscle move in a coordinated manner, and the coordinated movement control process is as follows:

[0018] The Kalman filter algorithm is used to fuse the data of the angular velocity sensor and the pressure sensor to estimate the current state of the hip joint module;

[0019] The position, velocity, and force states provided by the Kalman filter are used as feedback signals to calculate the error between the current state and the final state of task completion; the pneumatic artificial muscle parameters and joint motor parameters are adjusted in real time according to the current error.

[0020] As a further implementation, the threshold range of the tilt angle is 15 to 35 degrees.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) The present invention adopts a redundant design and installs an inclination sensor and a gyroscope at the same time to detect angle signals. Even if one of the sensors fails, it will not affect the operation, ensuring that the device can operate normally when the hybrid drive switches the drive mode, thereby improving the reliability and fault tolerance of the device. When the hybrid drive assists in carrying, pneumatic drive is selected for lifting and lowering objects. The pneumatic drive has greater explosive power, which can solve the problem of high energy consumption when only the motor drive is used, and reduce the number of replacement or charging times. The motor drive is selected for the walking and moving process, which can solve the problem of the pneumatic drive's imprecise movements during the carrying process.

[0023] (2) The present invention fuses the detection data of the angular velocity sensor and the pressure sensor to estimate the current state of the hip joint module; and uses the position, velocity, and force states provided by the Kalman filter as feedback signals to calculate the error between the current state and the final task completion state, and then adjusts the pneumatic valve opening of the pneumatic artificial muscle and the current, speed, and position of the motor in real time according to the current error to ensure that the movements of the joint motor and the pneumatic artificial muscle are coordinated and consistent, thereby improving the perception accuracy of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0025] Figure 1 is a schematic structural diagram of a hybrid drive power-assisted exoskeleton device according to one or more embodiments of the present invention;

[0026] Figure 2 is a control flow chart of a hybrid drive power-assisted exoskeleton device according to one or more embodiments of the present invention.

[0027] Among them, 1. shoulder strap, 2. back body, 3. arm strap, 4. position sensor, 5. battery, 6. pneumatic artificial muscle, 7. tilt sensor, 8. pressure sensor, 9. angular velocity sensor, 10. hip joint module, 11. gyroscope, 12. strap, 13. support arm. DETAILED DESCRIPTION

[0028] It should be noted that the following detailed descriptions are illustrative and intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0029] Embodiment 1:

[0030] This embodiment provides a hybrid drive power-assisted exoskeleton device, such as Figure 1 and Figure 2 As shown, it includes a back body 2, a hip joint module 10, a pneumatic artificial muscle 6, a joint motor, a sensor assembly, a control assembly, etc. The back body 2 is in the form of a backpack, and the back body 2 is equipped with two shoulder straps 1 for the operator to wear; the back body 2 is also connected to two arm straps 3, and the ends of the arm straps 3 are provided with loops for the operator to wear on the arms. The hip joint modules 10 are symmetrically arranged on both sides of the back body 2 and are rotatably connected to the back body 2; the hip joint modules 10 are connected to the support arms 13 through the straps 12, and the support arms 13 have a clamping portion, which is clamped with the operator's legs through the clamping portion.

[0031] The hip joint module 10 is connected to the pneumatic artificial muscle 6 arranged in the back body 2, and the hip joint module 10 is installed with a joint motor. The pneumatic artificial muscle 6 and the joint motor constitute a hybrid driving mode; the actions of lifting and lowering objects are driven by pneumatic drive, and the process of walking and carrying objects is driven by joint motor drive. By reasonably planning different actions and using different driving modes, accurate and efficient transportation of objects can be achieved, and the service life of the device can be extended.

[0032] There are two pneumatic artificial muscles 6, which are symmetrically arranged relative to the midline of the back body 2. The pneumatic artificial muscles 6 are of an existing structure, which are composed of an elastic rubber tube and a braided mesh sleeve; the pneumatic artificial muscles 6 are connected to a rope and pulley system, the rope is composed of nylon material, and is used to transmit the contraction force of the pneumatic artificial muscles 6 to the hip joint module 10, and the pulley system is used to change the direction of the force, so that the force is more effectively transmitted to the hip joint module 10, and the hip joint module 10 is driven to assist.

[0033] A battery 5 is also installed inside the back body 2, and the motor is connected to the battery 5 and the sensor assembly through a wire. In this embodiment, the battery 5 is a lithium battery 5, which is installed at the waist position and is light in weight.

[0034] In this embodiment, the sensor assembly includes a pressure sensor 8, a tilt sensor 7, a gyroscope 11, a position sensor 4, and an angular velocity sensor 9. The control assembly includes an MCU microcontroller and a PLC controller. The position sensor 4 is used to detect and measure the position of an object. The angular velocity sensor 9, the tilt sensor 7, and the gyroscope 11 are mainly used to detect the state of the human body. The tilt sensor 7 and the gyroscope 11 are designed to be redundant. When the hybrid drive switches the driving mode, the sensor and the controller need to be intact. The tilt sensor 7 and the gyroscope 11 are installed at the same time in this embodiment, mainly to detect the tilt angle of the body. Even if one of the sensors fails, it will not affect the work.

[0035] Specifically, the gyroscope 11 outputs the angular velocity around each axis in real time, and calculates the angle change by integration:

[0036] ;

[0037] in, θ ( t ) is the angle at time t, θ (0) is the initial angle, ω ( t ’ ) is at time t ’ The angular velocity measured at the moment.

[0038] The tilt sensor 7 calculates the tilt angle in the following way:

[0039] ;

[0040] in, h bend Indicates the height of a person when bending over. d Indicates the horizontal distance when a person bends.

[0041] A threshold range of the tilt angle is preset, and before the tilt angle reaches the threshold range, the joint motor is used for driving, i.e. walking and carrying objects; when the tilt angle is within the threshold range, pneumatic drive is used, i.e. lifting and lowering objects.

[0042] In this embodiment, the threshold range is 15-35 degrees. When carrying objects, the ideal bending angle should be as small as possible to reduce the burden on the waist. Specifically:

[0043] Ideal state: Keep your back as straight as possible, and the bending angle of the waist should not exceed 15~20°.

[0044] Maximum safe angle: If you have to bend over, the bending angle of the waist should not exceed 30~40°.

[0045] Therefore, the advantage of selecting a threshold in the range of 15 to 35 degrees in this embodiment is that the driving mode can be switched at 15 degrees, which improves the smoothness of the work. The range is expanded to 35 degrees because the extreme angle when carrying objects must be taken into consideration.

[0046] The pressure sensor 8 is used to obtain the state of the pneumatic artificial muscle 6, and the angular velocity sensor 9 is used to detect the angle of the joint motor. The MCU microcontroller is used to receive the signals detected by the position sensor 4, the angular velocity sensor 9, the inclination sensor 7 and the gyroscope 11, and transmit the signals to the PLC controller, which controls the exoskeleton device to switch the drive mode in time. The torque calculator transmits the torque information to the joint motor, and the joint motor adjusts the speed to carry and move. The joint motor is equipped with a motor encoder, which is used to obtain the position and speed of the joint motor.

[0047] Embodiment 2:

[0048] The present embodiment provides a control method for a hybrid-driven assisted exoskeleton device. Based on the hybrid-driven assisted exoskeleton device described in Embodiment 1, it is determined whether the tilt angle is within a threshold range according to the detection signals of the gyroscope 11 and the tilt sensor 7. When the tilt angle is within the threshold range, it is considered as a squatting and lifting action or a squatting and lowering action, and the pneumatic artificial muscle 6 drives the hip joint module 10 to move; when the tilt angle is not within the threshold range, it is considered as a moving action for carrying an object, and the joint motor drives the hip joint module 10 to move.

[0049] The specific steps are as follows:

[0050] S1: Preparation, including charging the battery and inflating the pneumatic artificial muscle 6; the operator wears the exoskeleton device.

[0051] S2: The position sensor 4 at the arm detects and measures the position of the object.

[0052] S3: The operator leans and squats to lift the object, while the gyroscope 11 and the inclination sensor 7 perform detection and transmit the detection signal to the MCU microcontroller. The MCU microcontroller processes the signal and transmits it to the PLC controller. The PLC controller controls the exoskeleton to adopt pneumatic drive according to the predetermined signal. At this time, the pneumatic artificial muscle 6 assists the operator through the pulley and rope system inside the hip joint module 10.

[0053] Among them, the pressure sensor 8 collects the state of the pneumatic artificial muscle 6 in real time. In addition, the Kalman filter algorithm is used to fuse the data of the angular velocity sensor 9 and the pressure sensor 8 to estimate the current state of the hip joint module 10. According to the position, speed, and force states provided by the Kalman filter as feedback signals, the error between the current state and the final task completion state is calculated, and then the pneumatic valve opening of the pneumatic artificial muscle 6 and the current, speed, and position of the motor are adjusted in real time according to the current error to ensure that the joint motor and the pneumatic artificial muscle 6 move in a coordinated manner and improve the perception accuracy of the device.

[0054] S4: The operator lifts the object and moves it. At this time, the gyroscope 11 and the tilt sensor 7 detect that the human body is in the non-threshold range, and transmit the signal to the control component to control the exoskeleton to use the joint motor to drive the hip joint module 10 to complete the power assistance.

[0055] Among them, the motor encoder obtains the position and speed data of the joint motor in real time.

[0056] S5: Similar to S2 and S3, the operator squats and tilts his body to put down the object. At this time, the gyroscope 11 and the tilt sensor 7 detect signals and transmit them to the control component, which controls the exoskeleton to use pneumatic drive to provide power assistance.

[0057] S6: Repeat steps S2-S5 to complete the process of transporting other objects.

[0058] In this embodiment, the joint motor is controlled using a PID control algorithm to generate a control signal according to the target position and the current position. The pneumatic artificial muscle 6 is controlled using an MPC model predictive control algorithm to generate an air pressure control signal according to the target state and the current state.

[0059] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method for a hybrid drive power-assisted exoskeleton device, characterized in that: The device comprises: A hip joint module is rotatably connected to both sides of the back body, the hip joint module is connected to the pneumatic artificial muscle and the joint motor, and the pneumatic artificial muscle and the joint motor are connected to the control component; The sensor assembly includes a pressure sensor, an inclination sensor, and a gyroscope. The pressure sensor is used to obtain the state of the pneumatic artificial muscle. The inclination sensor and the gyroscope are used to detect the inclination angle so that the control assembly can control the pneumatic artificial muscle or joint motor to work according to the inclination angle of the human body. The control method comprises: Whether the tilt angle is within a threshold range is determined based on the detection signals of the gyroscope and the inclination sensor. When the tilt angle is within the threshold range, it is considered as a squatting and lifting or squatting and lowering action, and the pneumatic artificial muscle drives the hip joint module to move; when the tilt angle is not within the threshold range, it is considered as a moving action for carrying an object, and the joint motor drives the hip joint module to move.

2. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The control component includes an MCU microcontroller and a PLC controller. The MCU microcontroller is used to receive detection signals from a gyroscope and an inclination sensor and transmit the signals to the PLC controller. The PLC controller is used to control the pneumatic artificial muscle.

3. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The back body is connected to an arm strap, and a position sensor is installed on the arm strap; the position sensor is used to detect and measure the position of an object.

4. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The sensor assembly also includes an angular velocity sensor, which is used to detect the angular velocity of the hip joint module.

5. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The joint motor is equipped with a motor encoder, and the motor encoder is used to obtain the position and speed of the joint motor.

6. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: Position sensors are previously used to detect and measure the position of objects.

7. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The joint motor adopts PID control to generate a control signal according to the target position and the current position; the pneumatic artificial muscle adopts MPC model predictive control to generate an air pressure control signal according to the target state and the current state.

8. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The joint motor and the pneumatic artificial muscle move in a coordinated manner, and the coordinated movement control process is as follows: The Kalman filter algorithm is used to fuse the data of the angular velocity sensor and the pressure sensor to estimate the current state of the hip joint module; The position, velocity, and force states provided by the Kalman filter are used as feedback signals to calculate the error between the current state and the final state of task completion; the pneumatic artificial muscle parameters and joint motor parameters are adjusted in real time according to the current error.

9. The control method of a hybrid drive power-assisted exoskeleton device according to claim 1, characterized in that: The threshold range of the tilt angle is 15-35°.

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