A bionic snake-like search and rescue robot based on tactile drive

Abstract

The present invention discloses a bionic snake-like search and rescue robot based on tactile drive, comprising: a snake-like robot body, the snake-like robot body comprising a plurality of motion units, two adjacent motion units being connected end to end and arranged orthogonally, each motion unit comprising a motor, a U-shaped connector and a strain gauge for tactile sensing; a snake-like robot driving system, the snake-like robot driving system comprising a host computer, a PID controller and a mode controller, the mode controller being connected to the host computer and the snake-like robot body respectively and transmitting the deformation signal generated by the strain gauge to the host computer; the host computer being used to process the data transmitted by the snake-like robot body and drive the operation of the motor through the PID controller. The present invention equips the bionic snake-like search and rescue robot with a tactile sensor to identify the environmental terrain, better control the torque of the snake-like robot, adjust the posture of the snake-like robot, and realize accurate search and rescue in an unknown environment.

Description

Technical Field

[0001] The invention belongs to the technical field of search and rescue robots, and in particular relates to a bionic snake-like search and rescue robot based on tactile drive. Background Art

[0002] Natural disasters and man-made disasters occur from time to time. The large-scale collapse of buildings, aftershocks of earthquakes, gas leaks in mines, etc. caused by disasters seriously hinder the effective implementation of rescue work. Search and rescue robots can provide rescue personnel with post-disaster ruins search and auxiliary rescue services. Bionic search and rescue robots have been effectively applied at home and abroad. However, most search and rescue robots only work on the ground and cannot go deep into the narrow gaps of ruins. They also lack autonomy and flexibility in movement, and the search range is very limited, which greatly reduces the rescue efficiency. At present, bionic snake-like robots have broad application prospects in search and rescue robots. If the bionic snake-like robot is added with tactile torque control, the snake-like robot can go deep into the narrow gaps of ruins to search for trapped people, and at the same time perform some environmental detection and data transmission work, and provide some necessary materials for the trapped people, this can better play the role of bionic snake-like robots in post-disaster rescue. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the above-mentioned prior art and to provide a bionic snake-like search and rescue robot based on tactile drive. By equipping the bionic snake-like search and rescue robot with a tactile sensor to identify the terrain of the environment, the torque of the snake-like robot can be better controlled, the posture of the snake-like robot can be adjusted, and accurate search and rescue in unknown environments can be achieved.

[0004] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is to provide a bionic snake-like search and rescue robot based on tactile drive, including: a snake-like robot body, the snake-like robot body including a plurality of motion units, two adjacent motion units are connected end to end and are orthogonally arranged, each of the motion units includes a motor, a U-shaped connector and a strain gauge for tactile sensing; a snake-like robot driving system, the snake-like robot driving system includes a host computer, a PID controller and a mode controller, the mode controller is respectively connected to the host computer and the snake-like robot body and transmits the deformation signal generated by the strain gauge to the host computer; the host computer is used to process the data transmitted by the snake-like robot body and drive the operation of the motor through the PID controller; the PID controller includes a torque module control loop composed of a position PID control module, a speed PID control module and a torque PID control module, the torque generated by the position PID control module and the torque generated by the speed PID control module are transmitted to the torque PID control module together with the torque preset by the host computer, and the torque required by the snake-like robot body is output after recalculation by the torque PID control module to drive the motor to operate.

[0005] Furthermore, the mode controller is connected to the host computer via RS485 serial communication to receive and process control instructions transmitted by the host computer.

[0006] Furthermore, the mode controller is connected to the snake-like robot body via a UART bus, and is used to send the control command to each of the motors to control the movement direction of the snake-like robot.

[0007] Furthermore, the U-shaped connector in each of the motion units includes a first U-shaped connector and a second U-shaped connector, the first U-shaped connector is connected to the steering wheel of the motor by screws, and the second U-shaped connector is arranged on the opposite side of the first U-shaped connector and is hingedly connected to the motor.

[0008] Furthermore, the first U-shaped connector and the second U-shaped connector in each of the motion units may be combined into an annular buckle, and the annular buckle is used to clamp adjacent motion units.

[0009] Furthermore, the tail of the snake-like robot body is equipped with a thin hose that can transport nutrient solution and oxygen.

[0010] Furthermore, a camera module is provided on the head of the snake-like robot body, and the camera module is used to collect images during the search and rescue process and transmit the images back to a host computer.

[0011] Furthermore, a microphone is provided on the snake-like robot body and the microphone is used to collect sounds during the search and rescue process and transmit the sounds back to the host computer.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] 1. Based on the snake-like robot, the present invention improves its mechanical structure and adds flexible torque control based on tactile perception, so that it can meet the movement requirements of narrow slit search and better play the search and rescue function of the snake-like robot.

[0014] 2. The present invention equips the snake-like search and rescue robot with visual, auditory and tactile sensors to transmit the image and sound data in the accident ruins to the outside world in real time, realize the internal search of the collapsed ruins, greatly ensure the life safety of the rescue team members, and improve the efficiency and accuracy of on-site rescue.

[0015] 3. The present invention carries a thin hose at the tail of the snake-like robot. After searching for the injured person, the robot can replenish drinking water and liquid food in the thin hose and return to the injured person for food supply, thereby providing time guarantee for further rescue work.

[0016] The present invention is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the snake-like robot body in the present invention.

[0018] Figure 2 It is a schematic diagram of the structural explosion of the snake-like robot body motion unit in the present invention.

[0019] Figure 3 It is a schematic diagram of the structure of the snake-like robot body motion unit in the present invention.

[0020] Figure 4 This is the torque module control loop in the present invention.

[0021] Figure 5 This is a control flow chart of the snake-like robot during movement in the present invention.

[0022] Figure 6 It is a simulation of the creeping gait of the snake-like robot body in the present invention.

[0023] Description of reference numerals:

[0024] 1—motor; 2—first U-shaped connecting piece; 3—second U-shaped connecting piece;

[0025] 4—Thin hose. DETAILED DESCRIPTION

[0026] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0029] In order to enable the search and rescue robot to have the ability to explore narrow gaps and move flexibly, the present invention provides a bionic snake-like search and rescue robot based on tactile drive, which can realize its flexible torque control through a tactile sensor, and the bionic snake-like search and rescue robot comprises:

[0030] The snake robot body, such as Figure 1 As shown, the snake-like robot body includes a plurality of motion units, and the number of the motion units of the snake-like robot can be adjusted according to actual needs. The snake-like robot body selected in this embodiment includes ten motion units, and two adjacent motion units are connected end to end and are orthogonally arranged. This structural design can make each motion unit not interfere with each other and independently complete their own instructions. Each of the motion units includes a motor 1, a U-shaped connector for connecting two adjacent motion units, and a strain gauge for tactile sensing, and the strain gauge is arranged on the surface of the motor 1, wherein the motor 1 is an XH540 servo. The application of the servo on the snake-like robot can ensure that the snake-like robot adapts to and maintains motion in the working environment. The tactile sensor uses strain gauges because they are small in size, high in precision, and have linear characteristics. They can measure the strain of an object. They are resistors whose resistance is proportional to the applied strain. Since the resistance change caused by the strain gauge when it is deformed is very small, the resistance change signal when the strain gauge is deformed during operation usually needs to be converted into an electrical signal through a bridge for transmission. When the strain gauge is added to the robot, the external force can be calculated based on the change in its resistance value and output to the mode controller, so that the snake-like robot body can sense the position of the contact point, the size and direction of the contact force, and adjust the posture of the snake-like robot in real time according to the relevant environmental information, thereby realizing adaptive motion.

[0031] A snake-like robot driving system, the snake-like robot driving system includes a host computer, a PID controller and a mode controller, the mode controller is connected to the host computer and the snake-like robot body respectively and transmits the deformation signal generated by the strain gauge to the host computer, the strain gauge and the mode controller are connected through a DuPont line, the strain gauge converts the resistance value when deformation occurs into an electrical signal and transmits it to the mode controller, the mode controller then transmits the electrical signal to the host computer through the serial port, and after processing by the host computer, the pressure data collected by the strain gauge can be directly displayed, and then the position of the snake-like robot body can be determined; the host computer is used to process the data transmitted by the snake-like robot body and drive the operation of the motor 1 through the PID controller, and the host computer obtains the location of the snake-like robot body After the position is determined and data analysis is performed, a control instruction is input into the host computer in order to expect the snake-like robot body to move according to the control instruction, and the control instruction is transmitted to the PID controller via the mode controller; as known in the art, the PID controller is a driving component on the motor 1, which controls the torque, speed and position of the motor shaft by adjusting the provided current and voltage, and the PID controller includes a torque module control loop composed of a position PID control module, a speed PID control module and a torque PID control module. The torque generated by the position PID control module and the torque generated by the speed PID control module are transmitted to the torque PID control module together with the torque preset by the host computer, and the torque required by the snake-like robot body is output after recalculation by the torque PID control module to drive the motor 1 to run;

[0032] Specifically, Figure 4 As shown, where θ d Set the target position of the snake robot, θ m is the current position of the snake robot, and the target position θ d With the current position θ m Inputting PID position control can generate a torque; Set a target speed for the snake robot, is the current speed of the snake robot, and the target speed is and the current speed The input speed PID control module can also generate a torque; the torque generated by the position PID control module and the torque generated by the speed PID control module are combined with the torque τ preset by the host computer. d Transmitted to PID torque control together with the current torque τ m After comparison, the torque required by the snake-like robot body is recalculated;

[0033] Specifically, the mode controller is connected to the host computer via RS485 serial communication, receives and processes the control instructions transmitted by the host computer; the mode controller is connected to the snake-like robot body via a UART bus, and is used to send the control command to each motor (1) to control the movement direction of the snake-like robot. The user inputs the control instruction in the host computer, hoping that the snake-like robot can move according to the control instruction, and the control instruction is transmitted to the mode controller via RS485 serial communication. After receiving the control instruction, the mode controller determines the direction in which the snake-like robot body is about to move, converts the control instruction into corresponding motion parameters and generates a corresponding motion trajectory. The mode controller sends the control instruction to each motor 1 via the UART bus to expect the snake-like robot body to move according to the control instruction.

[0034] like Figure 2 , Figure 3 As shown, the U-shaped connector in each of the motion units of the snake-like robot body includes a first U-shaped connector 2 and a second U-shaped connector 3, wherein the first U-shaped connector 2 is connected to the steering wheel of the motor 1 by screws, and the second U-shaped connector 3 is arranged on the opposite side of the first U-shaped connector 2 and is hingedly connected to the motor 1. Figure 3 As shown, the first U-shaped connector 2 and the second U-shaped connector 3 in each of the motion units can be combined into an annular buckle, and the connection between the first U-shaped connector 2 and the second U-shaped connector 3 can be fixed by screws. The annular buckle is used to clamp adjacent motion units, and the annular buckle clamps the motor 1 of the adjacent motion unit. Such a movable connection method can make the snake-like robot move flexibly and better complete the movement behaviors of crawling and rolling.

[0035] like Figure 1 As shown, the tail of the snake-like robot body is equipped with a thin hose 4 that can transport nutrient solution and oxygen. When the bionic snake-like search and rescue robot senses that there are injured people, it can recall the snake-like robot body and replenish a certain amount of nutrient solution or oxygen in the carried thin hose 4, and then send it to the injured person through the snake-like robot body again, providing time guarantee for further rescue work.

[0036] The head of the snake-like robot body is provided with a camera module, and the camera module is used to collect images during the search and rescue process and transmit the images back to the host computer. In this embodiment, a USB2.0 industrial camera is used to connect the camera to the host computer through a serial port, and the Python programming software Pycharm is used to perform visual programming on it, so that the camera can be called and turned on, and the image can be processed, and the collected visual information is transmitted to the host computer for display. A microphone is provided on the snake-like robot body and the microphone is used to collect sounds during the search and rescue process and transmit the sounds back to the host computer. A speaker is provided on the host computer, and the sound reception of the microphone on the snake-like robot body can be detected by adjusting the sound control panel of the host computer. The camera and the microphone are connected to the host computer by wires, and the wired connection can make the signal transmission smooth in special environments to ensure transmission efficiency.

[0037] The snake-like robot provided by the present invention develops a creeping gait based on the movement characteristics of biological snakes, so that the snake-like robot body can move forward or backward. At the same time, based on the characteristics of the mechanical structure of the snake-like robot in which the movement joints are orthogonally arranged, a spiral rolling motion is developed, so that the snake-like robot body can complete tree climbing or pole climbing.

[0038] Among them, the creeping gait planning is as follows:

[0039] The reason why the snake-like robot can achieve creeping is that the friction coefficient of the snake body forward is smaller than the friction coefficient backward. Therefore, in gait planning, it is assumed that the friction coefficient of the snake-like robot backward is much larger than the friction coefficient forward. Based on this assumption, the creeping process of the snake-like robot is simulated by the propulsion of a triangular waveform.

[0040] like Figure 6 As shown in the figure, the joints of the snake robot are simplified into n planar linkage mechanisms with a length of L. The initial state is assumed to be a straight line. The creeping process can be divided into the following three stages:

[0041] 1. Wave crest generation stage: By controlling the rotation of motor 1 at driving joints 1, 2, and 3, driving joint 2 is arched to form a wave crest. Since the friction coefficient of the snake-like robot body is relatively large, the tail of the snake-like robot body moves forward when arching. Figure 6 As shown in b. Assuming that the angle between the rod and the x-axis is α, then the forward displacement of the tail is S = 2L (1-cosα);

[0042] 2. Wave crest transition stage: By controlling the rotation of motor 1 driving joints 1, 2, 3, and 4, the wave crest transitions from joint 2 to joint 3, such as Figure 6The bc stage is the process of pushing the snake-like robot body forward; the cd stage is the process of pulling the tail of the snake-like robot body forward, at which time the snake-like robot body will move forward a certain distance;

[0043] 3. Wave crest transfer stage: Repeat the above process until the snake robot reaches Figure 6 The state of e in the middle finally returns to a straight line, thus completing the peristalsis process.

[0044] Among them, the spiral rolling gait is as follows:

[0045] The orthogonal distribution of the movement joints of the snake-like robot body enables the snake-like robot body to have the three-dimensional movement ability to climb trees with a spiral rolling gait. To allow the snake-like robot body to climb trees or poles with a spiral rolling gait, it is necessary to ensure that the friction between the climbed object and the snake-like robot body is large enough, and it is necessary to understand the angles that each joint of the snake-like robot needs to rotate at different times during the spiral rolling movement. The method of using a mathematical continuum model for analysis and then applying the results to a mechanical discrete snake-like robot model to achieve the tree climbing or pole climbing movement of the snake-like robot is derived. The formula is: When the snake-like robot climbs a tree in a spiral rolling gait, it is always in a state of being wrapped around the tree with equal pitch. After the snake-like robot body hugs the tree tightly, its odd-numbered joints and even-numbered joints rotate to corresponding angles respectively, allowing the snake-like robot body to climb the tree in a spiral rolling gait.

[0046] The working principle of the present invention is:

[0047] During the movement of the snake-like robot body, the strain gauge deforms to generate a corresponding resistance value change signal, which is converted into an electrical signal and transmitted to the mode controller. The mode controller feeds the signal back to the host computer, which can directly read the collected pressure data after data processing. A trigger value is set in the control program of the host computer. When the pressure data exceeds this trigger value, the program instruction for the motor to move in the opposite direction is executed. The instruction is transmitted to each motor 1 through the mode controller, thereby adjusting the posture of the snake-like robot body in the hope that the snake-like robot can adjust its posture.

[0048] like Figure 5As shown, the host computer in the present invention adopts a control system with a three-layer structure of an instruction layer, a planning layer and a behavior layer. The instruction layer is responsible for processing movement modes, such as the gait, speed, and steering of the snake movement, and sending control information to the mode controller. The instructions are converted into motion parameters by the mode controller to generate a COM trajectory, which is then sent back to the planning layer of the host computer. The planning layer calculates the angle trajectory through inverse kinematics and sends the information to the behavior layer. Finally, the behavior layer converts the required angle position into a torque value through a PID controller, drives the motor 1 to move, and enables the snake-like robot body to complete the corresponding gait adjustment.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A bionic snake-like search and rescue robot based on tactile drive, It is characterized in that include: A snake-like robot body, the snake-like robot body comprising a plurality of motion units, two adjacent motion units being connected end to end and arranged orthogonally, each of the motion units comprising a motor (1), a U-shaped connector and a strain gauge for tactile sensing; A snake-like robot driving system, the snake-like robot driving system comprising a host computer, a PID controller and a mode controller, the mode controller being connected to the host computer and the snake-like robot body respectively and transmitting the deformation signal generated by the strain gauge to the host computer; the host computer being used to process the data transmitted by the snake-like robot body and drive the operation of the motor (1) through the PID controller; the PID controller comprising a torque module control loop consisting of a position PID control module, a speed PID control module and a torque PID control module, the torque generated by the position PID control module and the torque generated by the speed PID control module being transmitted to the torque PID control module together with the torque preset by the host computer, and the torque required by the snake-like robot body is output after recalculation by the torque PID control module to drive the motor (1) to operate.

2. The bionic snake-like search and rescue robot according to claim 1, It is characterized in that The mode controller is connected to the host computer via RS485 serial communication, and receives and processes control instructions transmitted by the host computer.

3. The bionic snake-like search and rescue robot according to claim 2, It is characterized in that The mode controller is connected to the snake-like robot body via a UART bus and is used to send the control instruction to each motor (1) to control the movement direction of the snake-like robot.

4. The bionic snake-like search and rescue robot according to claim 1, It is characterized in that The U-shaped connecting member in each of the motion units comprises a first U-shaped connecting member (2) and a second U-shaped connecting member (3); the first U-shaped connecting member (2) is connected to the steering wheel of the motor (1) by screws; the second U-shaped connecting member (3) is arranged on the opposite side of the first U-shaped connecting member (2) and is hingedly connected to the motor (1).

5. The bionic snake-like search and rescue robot according to claim 4, It is characterized in that The first U-shaped connecting piece (2) and the second U-shaped connecting piece (3) in each of the motion units can be combined into an annular buckle, and the annular buckle is used to clamp adjacent motion units.

6. The bionic snake-like search and rescue robot according to claim 1, It is characterized in that The tail of the snake-shaped robot body is equipped with a thin hose (4) that can transport nutrient solution and oxygen.

7. The bionic snake-like search and rescue robot according to claim 6, It is characterized in that The head of the snake-like robot body is provided with a camera module, and the camera module is used to collect images during the search and rescue process and transmit the images back to the host computer.

8. The bionic snake-like search and rescue robot according to claim 7, It is characterized in that The snake-like robot body is provided with a microphone and the microphone is used to collect sounds during the search and rescue process and transmit the sounds back to the host computer.

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