CN111923022A

CN111923022A - Unconstrained mobile soft robot and driving method thereof

Info

Publication number: CN111923022A
Application number: CN202010651297.3A
Authority: CN
Inventors: 祝庆; 许明; 何龙; 陈国金
Original assignee: Hangzhou Dianzi University
Current assignee: Hangzhou Dianzi University
Priority date: 2020-07-08
Filing date: 2020-07-08
Publication date: 2020-11-13
Anticipated expiration: 2040-07-08
Also published as: CN111923022B

Abstract

The invention discloses an unconstrained mobile soft robot and a driving method thereof. The existing soft robot needs to carry elements such as a hydraulic source, a valve body and the like, which increases the weight of the soft robot. The invention includes a front end outer housing, a rear end outer housing, and a driver. The front end outer shell and the rear end outer shell are connected together through two drivers which are arranged side by side. The driver is composed of a stack of M drive units. The driving unit includes a positive electrode, a negative electrode, and an elastic capsule. The positive electrode, the negative electrode and the center parts of the two side surfaces of the elastic capsule body are respectively fixed. The elastic capsule is filled with a liquid dielectric medium. According to the invention, the electrodes in the middle parts of the two sides of the elastic capsule body are applied with voltage to generate static Maxwell stress, and the middle parts of the two side surfaces of the elastic capsule body are extruded, so that the edge of the elastic capsule body is expanded, and the technical effect of driver extension is achieved; the driving method avoids the use of an additional hydraulic source and a plurality of control valves, and reduces the volume of the robot.

Description

Unconstrained mobile soft robot and driving method thereof

Technical Field

The invention belongs to the technical field of soft robots, and particularly relates to an unconstrained mobile soft robot and a driving method thereof.

Background

The use of a robot has become an indispensable product in industrial production and life, and the robot in the traditional sense mainly has a rigid structure, but the rigid structure material thereof causes that the robot cannot adapt to the change of a complex environment, which causes the robot to have the defects of large size, low safety and the like. As people become more and more aware of interactions with unstructured environments, robots must become less rigid and immobilized. The soft robot has good flexibility, can adapt to the external environment through self deformation, can operate in the environment with narrow space, and has wide application prospect in the aspects of rescue and detection. Meanwhile, the soft robot has good biocompatibility, cannot damage biological tissues, and is gradually concerned by medical workers. The software robot is an emerging research field, and related research is still in the initial stage. The existing soft robot usually needs to carry elements such as a hydraulic source, a valve body and the like, so that the weight of the soft robot is greatly increased, and the miniaturization, the light weight and the convenience of the soft robot are not facilitated.

Disclosure of Invention

The invention aims to provide an unconstrained mobile soft robot and a driving method thereof.

The invention relates to an unconstrained mobile soft robot which comprises a front-end outer shell, a rear-end outer shell and a driver. The front end outer shell and the rear end outer shell are connected together through two drivers arranged side by side. Both the front and rear outer housings can only move forward. The driver is in a long strip shape and consists of M driving units which are sequentially stacked. The driving unit includes a positive electrode, a negative electrode, and an elastic capsule. The positive electrode, the negative electrode and the center parts of the two side surfaces of the elastic capsule body are respectively fixed. The elastic capsule is filled with a liquid dielectric medium.

Preferably, the opposite sides of the elastic capsules in two adjacent driving units are both positive electrodes or both negative electrodes.

Preferably, the two sides of the front end outer shell and the rear end outer shell are both provided with one-way bearing wheels.

Preferably, the positive electrodes of the individual drive units within the same driver are connected together as the supply line for the driver. The negative electrodes of all the driving units in the same driver are grounded.

Preferably, the unconstrained mobile soft robot according to the present invention further includes an integrated circuit substrate. The integrated circuit substrate is arranged on the front end outer shell or the rear end outer shell and comprises a controller, a wireless module and a high-voltage generator. The control interface of the high-voltage generator is connected with the controller. Two voltage output interfaces of the high-voltage generator are respectively connected with power supply lines of the two drivers. The controller and the upper computer are in wireless communication through the wireless module.

Preferably, the side surfaces of the positive electrode and the negative electrode are both smaller than one half of the elastic capsule. The positive electrode and the negative electrode are both led out to the edge of the elastic bag body through the conductive strips. The conductive strips on the positive electrode and the negative electrode are oppositely oriented.

Preferably, the material of the elastic capsule is PDMS. The dielectric medium is plant transformer oil.

Preferably, the positive electrode and the negative electrode can deform along with the elastic capsule, and the materials are all ion-conductive polyacrylamide hydrogel.

Preferably, the edges of the opposite sides of the elastic capsules in two adjacent driving units are stuck and fixed together.

The driving method of the unconstrained mobile soft robot comprises a linear driving method and a steering driving method.

The linear driving method is concretely as follows:

step one, applying voltage to the positive electrode and the negative electrode of the two drivers to enable the positive electrode and the negative electrode in the same driving unit to attract each other, extruding the central part of the elastic bag body, enabling the liquid dielectric medium in the elastic bag body to be extruded to the edge of the inner cavity of the elastic bag body, further enabling the edge of the elastic bag body to expand along the axial direction, and enabling the two drivers to extend. The rear housing shell remains stationary and the front housing shell moves forward under the push of the two drives.

And step two, powering off the two drivers, and shortening the two drivers to the initial length. The front housing is now stationary and the rear housing is moved forward by the pull of the two drives.

And step three, repeating the step one and the step two to realize linear driving.

The steering driving method comprises the following steps:

in the first step, of the two drivers, the driver positioned on the left side in the traveling direction is used as a left driver, and the driver positioned on the right side in the traveling direction is used as a right driver.

And step two, if the left side needs to be steered, applying voltage to the right driver to enable the right driver to extend and bend to the left side, and pushing the front end outer shell to steer to the left.

If the steering to the right side is needed, voltage is applied to the left driver, so that the left driver stretches and bends to the right side, and the front end outer shell is pushed to steer to the right.

And step three, powering off both the two drivers, and shortening the extended driver to the initial length. And the rear end outer shell is pulled to turn right.

And step four, repeatedly executing the step two and the step three until the direction is turned to the target direction.

The invention has the beneficial effects that:

1. according to the invention, the electrodes in the middle parts of the two sides of the elastic capsule body are applied with voltage to generate static Maxwell stress, and the middle parts of the two side surfaces of the elastic capsule body are extruded, so that the edge of the elastic capsule body is expanded, and the technical effect of driver extension is achieved; by adopting the driving method, the use of an additional hydraulic source and some control valves is avoided, the volume of the robot is greatly reduced, and the robot can realize no external circuit, namely unconstrained movement.

2. In the invention, the opposite side surfaces of two adjacent elastic capsules are both positive electrodes or both negative electrodes, so that the electrode plates on the opposite side surfaces of two adjacent elastic capsules repel each other, the extrusion force applied to the central parts of the elastic capsules can be further increased, and the driving efficiency of the invention is improved.

3. The whole driver of the invention does not have a rigid body, so that the invention can adapt to more complex external environment, can work in narrow space environment, and can be applied to aspects of rescue, detection and the like.

4. The invention controls the working state of the driver by the characteristics of the one-way bearing wheel, so that the driver can realize the motions of advancing and retreating, turning and the like in a plane.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic diagram of a single actuator in the present invention;

FIG. 3 is a schematic diagram of a single drive unit of the present invention;

fig. 4 is a schematic diagram of a deformation process from power-off to power-on of a single drive unit in the present invention.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

As shown in FIG. 1, an unconstrained mobile soft robot comprises a front-end outer shell 1-1, a rear-end outer shell 1-2, a driver 2, a one-way bearing wheel 3 and an integrated circuit substrate 4. The front end outer shell 1-1 and the rear end outer shell 1-2 are connected together through two drivers 2 arranged side by side and respectively used as the head and the tail of the soft robot. The two sides of the front end outer shell 1-1 and the rear end outer shell 1-2 are both provided with one-way bearing wheels 3. The one-way bearing wheel 3 is obtained by mounting a tire bead on an outer ring of the one-way bearing, and only forward rotation can cause the front end outer shell 1-1 or the rear end outer shell 1-2 to advance but not reverse.

As shown in fig. 2 and 3, the driver 2 has an elongated shape and is formed by stacking M drive units, where M is 19. The drive unit comprises a positive electrode 5, a negative electrode 6 and an elastic capsule 7. The positive electrode 5, the negative electrode 6 and the central parts of the two side surfaces of the elastic capsule body 7 are respectively fixed. The positive electrode 5 and the negative electrode 6 only cover the center of the side of the elastic capsule body 7 and leave a circle around the side of the elastic capsule body 7. The side surfaces of the positive electrode 5 and the negative electrode 6 are less than one half of the elastic capsule 7. The positive electrode 5 and the negative electrode 6 are both led out to the edge of the elastic capsule body 7 through conductive strips. The conductive strips on the positive electrode 5 and the negative electrode 6 are oppositely oriented to avoid the conductive strips on the positive electrode 5 and the negative electrode 6 from attracting each other. The elastic capsule body 7 is made of PDMS (polydimethylsiloxane), so that the elasticity is good and the property is stable; the elastomeric bladder 7 is filled with a liquid dielectric. The dielectric medium is plant transformer oil. The positive electrode and the negative electrode can deform along with the elastic capsule body 7, and ion conductive Polyacrylamide (PAM) hydrogel is adopted as the material.

The edges (circles around) of the opposite sides of the elastic capsules 7 in the two adjacent driving units are stuck and fixed together. The positive electrode 5 and the negative electrode 6 in two adjacent driving units are not fixed with each other and can be contacted or separated. The positions of the positive electrode 5 and the negative electrode 6 in two adjacent driving units are opposite, that is, the opposite sides of the elastic capsules 7 in two adjacent driving units are both the positive electrode 5 or both the negative electrodes. The positive electrodes 5 of the individual drive units within the same driver 2 are connected together as the supply line V for the driver. The negative electrodes 6 of the individual drive units within the same driver 2 are connected together and are connected to the ground of the high voltage generator.

As shown in fig. 4, for one driver 2, by applying voltages to the positive electrode and the negative electrode, an electric field can be induced in the liquid electrolyte, so that an electrostatic maxwell stress which is mutually attracted is generated between the positive electrode and the negative electrode; the positive electrode and the negative electrode that attract each other extrude the central part of the elastic capsule body 7, so that the liquid dielectric medium in the elastic capsule body 7 is extruded to the edge of the inner cavity of the elastic capsule body 7, and then the edge of the elastic capsule body 7 expands along the axial direction to generate axial displacement, and further the whole driver is extended. In addition, since the opposite side surfaces of two adjacent elastic capsules 7 are both positive electrodes 5 or both negative electrodes, the electrode plates on the opposite side surfaces of two adjacent elastic capsules 7 repel each other, further increasing the pressing force applied to the central portion of the elastic capsules 7.

The integrated circuit substrate 4 is mounted on the front end outer shell 1-1 or the rear end outer shell 1-2 and comprises a controller, a wireless module and a high voltage generator. The control interface of the high-voltage generator is connected with the controller. Two voltage output interfaces of the high-voltage generator are respectively connected with power supply lines V of the two drivers. The controller and the upper computer are in wireless communication through the wireless module. The controller is used for controlling the high-voltage generator to work and further controlling the driver 2 to stretch and retract, so that the motion control of the soft robot is realized. The wireless module is used for realizing the communication between the controller and the upper computer and realizing the remote control of the robot. The high voltage generator is used to provide the operating voltage required by the driver 2.

The linear driving method is concretely as follows:

step one, a controller applies voltage to power supply lines of two drivers 2 through a high-voltage generator, so that liquid electrolyte in each elastic capsule body induces an electric field to generate static Maxwell stress; the positive electrode and the negative electrode in the same driving unit are mutually attracted to extrude the central part of the elastic capsule body 7, so that the liquid dielectric medium in the elastic capsule body 7 is extruded to the edge of the inner cavity of the elastic capsule body 7, and the edge of the elastic capsule body 7 expands along the axial direction to generate axial displacement; thereby causing the two actuators 2 to elongate. Since the one-way bearing wheel 3 can only roll forward, the rear outer shell 1-2 is fixed at this time, and the front outer shell 1-1 moves forward under the push of the two drivers 2.

And step two, the controller removes the voltage applied to the two drivers 2 through the high-voltage generator, and the two drivers are both shortened to the initial length under the elastic action of the elastic capsule body. Since the one-way bearing wheel 3 can only roll forward, the front end outer housing 1-1 is fixed, and the rear end outer housing 1-2 moves forward under the push of the two drivers 2.

And step three, repeating the step one and the step two, and then realizing the continuous forward movement of the robot.

The steering driving method comprises the following steps:

And step two, if the left side needs to be steered, the controller applies voltage to the right driver through the high-voltage generator to enable the right driver to extend, and the extended right driver bends towards the left side because the left driver does not extend at the moment, so that the front end outer shell 1-1 is pushed to steer towards the left.

If the steering to the right side is needed, the controller applies voltage to the left driver through the high voltage generator to extend the left driver, and the extended left driver bends to the right side because the right driver does not extend at the moment, so that the front end outer shell 1-1 is pushed to steer to the right side.

And step three, the controller removes the voltage applied to the driver 2 through the high-voltage generator, and the stretched driver is shortened to the initial length under the elastic action of the elastic capsule body. Since the one-way bearing wheel 3 can only roll forward, the front end outer housing 1-1 is fixed, and the rear end outer housing 1-2 is turned toward the target direction under the pulling of the driver.

Claims

1. An unconstrained mobile soft robot comprises a front-end outer shell (1-1), a rear-end outer shell (1-2) and a driver (2); the method is characterized in that: the front end outer shell (1-1) and the rear end outer shell (1-2) are connected together through two drivers (2) arranged side by side; the front end outer shell (1-1) and the rear end outer shell (1-2) can only move forwards; the driver (2) is in a long strip shape and consists of M driving units which are sequentially stacked; the driving unit comprises a positive electrode (5), a negative electrode (6) and an elastic capsule body (7); the positive electrode (5), the negative electrode (6) and the center parts of the two side surfaces of the elastic bag body (7) are respectively fixed; the elastic capsule body (7) is filled with liquid dielectric medium.

2. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the opposite side surfaces of the elastic capsules (7) in the two adjacent driving units are both positive electrodes (5) or both negative electrodes.

3. An unconstrained mobile soft-bodied robot according to claim 1, wherein: and two sides of the front end outer shell (1-1) and the rear end outer shell (1-2) are respectively provided with a one-way bearing wheel (3).

4. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the positive electrodes (5) of the individual drive units in the same driver (2) are connected together as the supply lines for the driver; the negative electrodes (6) of all the driving units in the same driver (2) are all grounded.

5. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the invention relates to an unconstrained mobile soft robot, which also comprises an integrated circuit substrate (4); the integrated circuit substrate (4) is arranged on the front end outer shell (1-1) or the rear end outer shell (1-2) and comprises a controller, a wireless module and a high voltage generator; the control interface of the high-voltage generator is connected with the controller; two voltage output interfaces of the high-voltage generator are respectively connected with power supply lines of the two drivers; the controller and the upper computer are in wireless communication through the wireless module.

6. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the side surfaces of the positive electrode (5) and the negative electrode (6) are both smaller than one half of the elastic capsule body (7); the positive electrode (5) and the negative electrode (6) are both led out to the edge of the elastic bag body (7) through the conductive strips; the conductive strips on the positive electrode (5) and the negative electrode (6) are opposite in direction.

7. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the elastic capsule body (7) is made of PDMS; the dielectric medium is plant transformer oil.

8. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the positive electrode and the negative electrode can deform along with the elastic capsule body (7), and the materials are all ion-conductive polyacrylamide hydrogel.

9. An unconstrained mobile soft-bodied robot according to claim 1, wherein: the edges of the opposite sides of the elastic capsules (7) in the two adjacent driving units are stuck and fixed together.

10. The method as claimed in claim 1, wherein the method comprises the following steps: the method comprises a linear driving method and a steering driving method;

the linear driving method is concretely as follows:

step one, applying voltage to positive electrodes and negative electrodes of two drivers (2) to enable the positive electrodes and the negative electrodes in the same driving unit to attract each other, and extruding the central part of an elastic bag body (7) to enable liquid dielectric medium in the elastic bag body (7) to be extruded to the edge of an inner cavity of the elastic bag body (7), so that the edge of the elastic bag body (7) expands along the axial direction, and the two drivers (2) extend; at the moment, the rear end outer shell (1-2) is kept static, and the front end outer shell (1-1) moves forwards under the pushing of the two drivers (2);

step two, the two drivers (2) are powered off, and the two drivers are shortened to the initial length; at the moment, the front end outer shell (1-1) is static, and the rear end outer shell (1-2) moves forwards under the pulling of the two drivers (2);

step three, repeating the step one and the step two to realize linear driving;

the steering driving method comprises the following steps:

step one, in two drivers, a driver positioned on the left side of the traveling direction is used as a left driver, and a driver positioned on the right side of the traveling direction is used as a right driver;

step two, if the left side needs to be steered, applying voltage to the right driver to enable the right driver to extend and bend to the left side, and pushing the front end outer shell (1-1) to steer to the left;

if the driver needs to turn to the right side, voltage is applied to the left driver, so that the left driver stretches and bends to the right side, and the front end outer shell (1-1) is pushed to turn to the right side;

step three, the two drivers (2) are powered off, and the extended driver is shortened to the initial length; pulling the rear end outer shell (1-2) to turn right;