CN110900620B

CN110900620B - Unconstrained soft robot and driving method thereof

Info

Publication number: CN110900620B
Application number: CN201911087915.XA
Authority: CN
Inventors: 许明; 戎铖; 陈国金
Original assignee: Hangzhou Dianzi University
Current assignee: Hangzhou Dianzi University
Priority date: 2019-11-08
Filing date: 2019-11-08
Publication date: 2021-02-19
Anticipated expiration: 2039-11-08
Also published as: CN110900620A

Abstract

The invention discloses an unconstrained soft robot and a driving method thereof. The soft robot adopts a pneumatic or hydraulic transmission driving mode, depends on a pneumatic or hydraulic tether, and cannot integrate and embed basic components into the robot to realize a bolt-free system, so that the soft robot cannot be applied to the fields of site survey and the like. The invention relates to an unconstrained soft robot which comprises a liquid storage tank, an intermediate execution mechanism, a first soft pump, a second soft pump, a snakeskin-like film and a control tank. The first soft pump and the second soft pump are soft bidirectional pumps. The soft bidirectional pump comprises a top layer, a top electrode pair, a channel layer, a top electrode pair and a bottom layer which are sequentially arranged. The snake skin bionic snake is bionic according to the body structure and the driving mode of the snake, and forward driving can be realized through anisotropic friction of the snake scale structure. The power source of the invention adopts a charge injection type micro soft pump structure, and the soft pump does not generate vibration and can realize silent and vibration-free work.

Description

Unconstrained soft robot and driving method thereof

Technical Field

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

Background

The use of a soft robot has become an indispensable product in industrial production and life, and the robot in the traditional sense is mainly based on a rigid structure, but the rigid structure material thereof causes that the robot cannot adapt to the change of a complex environment, so that the robot has 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. The software robot is an emerging research field, and related research is still in the initial stage. Therefore, the development of the software robot theory and the research of the related technology are of great significance to the development and application of the software robot technology.

Meanwhile, most soft robots are driven by rigid, noisy pumps, with drive components to propel the liquid into the machine. Since such robots need to be connected to heavy pumps via pipes, the autonomy is limited and much heavier. Conventional pumps are mostly heavy rigid systems comprising impellers, bearings and motors, which often require lubrication and generate noise, micro pumps are no exception, and also have the disadvantages of structural rigidity, numerous driving parts, lack of flexibility and scalability. In addition, the existing soft robot adopts a pneumatic or hydraulic transmission driving mode, depends on a pneumatic or hydraulic tether, and cannot integrate and embed basic components into the robot to realize a bolt-free system, so that the soft robot cannot be applied to the fields of site survey and the like.

Disclosure of Invention

The invention aims to overcome the defects that the conventional soft robot needs to be connected with a heavy pump through a pipe, and has limited autonomy and heavy weight.

The invention relates to an unconstrained soft robot which comprises a liquid storage tank, an intermediate execution mechanism, a first soft pump, a second soft pump, a snakeskin-like film and a control tank. A first liquid inlet and outlet and a second liquid inlet and outlet are formed in the top of the liquid storage box. The middle actuating mechanism comprises a first telescopic pipe and a second telescopic pipe. A first liquid through opening is formed in the first telescopic pipe; the second telescopic pipe is provided with a second liquid through hole. One end of the first telescopic pipe and one end of the second telescopic pipe are both fixed with the liquid storage box, and the other ends of the first telescopic pipe and the second telescopic pipe are both fixed with the control box. The first extension tube and the second extension tube are arranged side by side.

The first soft pump and the second soft pump are soft bidirectional pumps. The soft bidirectional pump comprises a top layer, a top electrode pair, a channel layer, a top electrode pair and a bottom layer which are sequentially arranged. The middle part of the channel layer is provided with a strip-shaped channel. The two ends of the top layer are respectively provided with a first flow passage hole and a second flow passage hole. The first flow channel hole and the second flow channel hole are respectively communicated with two ends of the strip-shaped channel on the channel layer. The top electrode pair and the bottom electrode pair have the same structure and are both in a comb-tooth electrode pair shape.

The first channel hole on the top layer of the first soft pump is connected with the first liquid inlet and outlet on the liquid storage box, and the second channel hole is connected with the first liquid through port on the first telescopic pipe. The first flow passage hole on the top layer of the second soft pump is connected with the second liquid inlet and outlet on the liquid storage box, and the second flow passage hole is connected with the second liquid through hole on the second telescopic pipe. The liquid storage tank, the first soft pump, the second soft pump, the first telescopic pipe and the second telescopic pipe are all filled with dielectric liquid.

The two first extension tubes and the second extension tube are both provided with a snakeskin film. The snake skin membrane comprises a main body membrane and a snake-like scale. The outer side surface of the main body membrane is provided with a plurality of snake-like scales. The inner ends of the snake-like scales are fixed with the main body membrane. The orientations of the outer ends of the snake-like scales are consistent. The snake-like scales on the main body membrane are contacted with the ground.

Preferably, the top electrode pair and the bottom electrode pair comprise a first comb-tooth electrode and a second comb-tooth electrode. The first comb electrode comprises a first lead-out piece, a first trunk strip and n first branch strips. The inner end of the first lead-out sheet is connected with one end of the first trunk strip. The n first branch strips are all arranged on the inner side edge of the first main strip and are sequentially arranged along the length direction of the first main strip. The second comb electrode comprises a second lead-out piece, a second main bar and n second branch bars. The inner end of the second lead-out sheet is connected with one end of the second main bar. The n second branch strips are all arranged on the inner side edge of the second main strip and are sequentially arranged along the length direction of the second main strip. The first trunk strip and the second trunk strip are respectively arranged on two sides of the strip-shaped channel. The outer ends of the n first branch bars and the n second branch bars are sequentially and alternately arranged. The n first branch strips and the n second branch strips are grouped in pairs to form n unit electrode pairs. The distance between the first branch bar and the second branch bar in one unit electrode pair is smaller than the distance between two adjacent unit electrode pairs. In the same unit electrode, the first branch strip is positioned on one side of the second branch strip close to the first flow channel hole.

Preferably, the distance between the first branch bar and the second branch bar in one unit electrode pair is 0.5mm, and the distance between two adjacent unit electrode pairs is 1 mm.

Preferably, the top electrode pair and the first comb electrodes in the bottom electrode pair are connected together to serve as a first input pin of the soft bidirectional pump. And the top electrode pair and a second lead-out piece of a second comb electrode in the bottom electrode pair are connected together to be used as a second input pin of the soft bidirectional pump.

Preferably, the control box is internally provided with a controller and a high-voltage generator. Two output pins in the first group of output interfaces of the high-voltage generator are respectively connected with a first input pin and a second input pin of the first soft pump. Two output pins in the second group of output interfaces of the high-voltage generator are respectively connected with the first input pin and the second input pin of the second soft pump. The control interface of the high-voltage generator is connected with the controller. The controller adopts a singlechip.

Preferably, the top of the liquid storage tank is further provided with a vent hole. Driven wheels are supported on two sides of the liquid storage box and the control box.

Preferably, the first soft pump and the second soft pump are respectively arranged on the first extension pipe and the second extension pipe.

Preferably, the thickness of the top layer and the bottom layer is 0.4 mm; the thickness of the channel layer was 0.5 mm. The top and bottom electrode pairs were each 30 μm thick. The top layer, the channel layer and the bottom layer are all organic silicon films. The organic silicon is polydimethylsiloxane. The top layer and the bottom layer are both bonded with the channel layer through a silicone adhesive film. Both the top electrode pair and the bottom electrode pair are made of stretchable silver materials.

Preferably, the snake-like scales are made of plastic sheets. Except the snake-like scales at the head end of the main body membrane, the inner ends of the other snake-like scales are covered by other snake-like scales.

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

The linear forward driving method is specifically as follows:

step one, the first soft pump is electrified in the forward direction, so that the dielectric liquid in the liquid storage tank flows to the first telescopic pipe by the forward pump liquid of the first soft pump, and the first telescopic pipe is extended.

Meanwhile, the second soft pump is electrified reversely and positively, so that the dielectric liquid in the liquid storage tank flows to the second telescopic pipe by the positive pumping of the second soft pump, and the second telescopic pipe is extended.

Under the action of the backward ground-grasping force of the snakeskin film, the first extension tube and the second extension tube push the control box to move forward. The direction from the outer end to the inner end of the snake-like scale is the advancing direction.

And step two, the first soft pump is electrified reversely, so that the dielectric medium liquid in the first telescopic pipe flows to the liquid storage tank by the reverse liquid pumping of the first soft pump, and the first telescopic pipe is shortened.

Meanwhile, the second flexible pump is electrified reversely, so that the dielectric liquid in the second flexible pipe flows to the liquid storage tank by the reverse liquid pumping of the second flexible pump, and the second flexible pipe is shortened.

Under the action of the backward ground-grasping force of the snakeskin film, the first telescopic pipe and the second telescopic pipe pull the liquid storage tank to move forward.

And step three, repeatedly executing the step one and the step two to realize continuous advancing.

The deflection driving method specifically comprises the following steps:

step one, one side of the first telescopic pipe and the second telescopic pipe far away from the deflection direction is used as a working telescopic pipe. The soft pump corresponding to the working telescopic pipe is used as the working soft pump.

And step two, the working soft pump is powered on positively, so that the working soft pump pumps liquid positively, the dielectric liquid in the liquid storage tank flows to the working telescopic pipe, and the working telescopic pipe extends. Under the action of backward ground-grasping force of the snakeskin film, the working telescopic pipe pushes the control box to deflect towards the target direction.

And step three, the working soft pump is reversely electrified, so that the dielectric liquid in the working telescopic pipe flows to the liquid storage tank by reversely pumping the liquid of the working soft pump, and the working telescopic pipe is shortened. Under the action of the backward ground-grasping force of the snakeskin film, the working telescopic pipe pulls the liquid storage tank to deflect towards the target direction.

And step four, repeating the step two and the step three until the deflection reaches the target angle.

The invention has the beneficial effects that:

1. the invention provides a small-sized unconstrained soft robot simulating a snakeskin structure according to the body structure and the driving mode of a snake, and forward driving can be realized through anisotropic friction of a snake scale structure.

2. The invention adopts a charge injection type micro soft pump structure; the soft body pump has no driving component, does not generate vibration, can realize silent and vibration-free work, has good stretchability, is an ideal small-sized and portable soft body micropump, and greatly reduces the mass load of a robot.

3. The middle actuating mechanism, the first soft pump, the second soft pump and the imitation snakeskin film are all flexible, so that the environmental adaptability of the invention is greatly enhanced.

Drawings

FIG. 1 is a schematic view of the overall structure of a hidden imitation snake skin membrane of the present invention;

FIG. 2 is a schematic side view of the present invention;

FIG. 3 is an exploded view of the soft body pump of the present invention;

FIG. 4 is a schematic diagram of the structure of the soft pump of the present invention.

Detailed Description

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

As shown in figures 1 and 2, the unconstrained soft robot comprises a liquid storage tank 1, an intermediate execution mechanism, a first soft pump 5, a second soft pump 8, a snakeskin-like film 12 and a control tank 11. Two ends of the middle actuating mechanism are respectively connected with the liquid storage box 1 and the control box 11. The first soft pump 5 and the second soft pump 8 are both arranged on the middle execution mechanism. The imitation snakeskin membrane 12 is disposed on the intermediate actuator. The top of the liquid storage box 1 is provided with a vent hole 3, a first liquid inlet and outlet 2 and a second liquid inlet and outlet 4. Driven wheels are supported on both sides of the liquid storage tank 1 and the control tank 11. The driven wheel can avoid sliding friction between the liquid storage tank 1 and the control tank 11 and the bottom surface, thereby reducing resistance.

The intermediate actuator comprises a first telescopic tube 6 and a second telescopic tube 9. A first liquid through opening 7 is formed in the first extension tube 6; the second extension tube 9 is provided with a second liquid through opening 10. When the first and second bellows 6 and 9 are filled with liquid, they will expand and when the liquid is withdrawn, they will contract. The two ends of the first extension tube 6 and the second extension tube 9 are both closed, one end of each of the first extension tube and the second extension tube is fixedly bonded with the liquid storage box 1, and the other end of each of the first extension tube and the second extension tube is fixedly bonded with the control box 11. The first extension pipe 6 and the second extension pipe 9 are arranged side by side from left to right. The first soft pump 5 and the second soft pump 8 are respectively arranged on the first extension pipe 6 and the second extension pipe 9. The first soft pump 5 and the second soft pump 8 are fixed at a single point, and the expansion of the first telescopic pipe 6 and the second telescopic pipe 9 is not influenced.

As shown in fig. 3 and 4, the first soft pump 5 and the second soft pump 8 are both soft bidirectional pumps based on charge injection. The soft bidirectional pump is in a strip shape and comprises a top layer 20, a top electrode pair 23, a channel layer 21, a bottom electrode pair 24 and a bottom layer 22 which are sequentially arranged from top to bottom. The thickness of the top layer 20 and the bottom layer 22 are both 0.4 mm; the thickness of the channel layer 21 is 0.5 mm. The top layer 20 and the bottom layer 22 are bonded to the channel layer 21 by a silicone adhesive film.

The top layer 20, the channel layer 21, and the bottom layer 22 are all organic silicon films. The organic silicon is Polydimethylsiloxane (PDMS). The top electrode pair 23 is printed on the inner side of the top layer 20 by 3D printing technology. The bottom electrode pairs 24 are printed on the inside of the bottom layer 22 by 3D printing technology. The top electrode pair 23 and the bottom electrode pair 24 are each 30 μm thick. Both the top electrode pair 23 and the bottom electrode pair 24 are made of stretchable silver material, specifically IMD/IME stretchable conductive silver paste. Since all the components of the soft bi-directional pump are flexible materials, it can freely deform with the intermediate actuator without restricting the actuation of the intermediate actuator. The middle of the channel layer 21 is provided with a stripe-shaped channel 19 by a laser cutting method. The top layer 20 has first and second flow channel holes 13 and 14 formed at both ends thereof, respectively. The first and second flow channel holes 13 and 14 communicate with both ends of the strip channel 19 on the channel layer 21, respectively.

The top electrode pair 23 and the bottom electrode pair 24 have the same structure, are both in a comb-tooth electrode pair shape, and comprise a first comb-tooth electrode and a second comb-tooth electrode. The first comb-tooth electrode includes a first lead-out piece 17, a first trunk bar 25, and n first branch bars 16, where n is 18. The inner end of the first lead-out piece 17 is connected with one end of the first trunk strip 25, and the outer end of the first lead-out piece leads out of the soft bidirectional pump. The n first branch bars 16 are all arranged at the inner side edge of the first main bar 25 and are sequentially arranged along the length direction of the first main bar 25. The second comb-tooth electrode includes a second lead-out piece 18, a second trunk strip 26, and n second branch strips 15. The inner end of the second lead-out piece 18 is connected with one end of the second main strip 26, and the outer end is led out of the soft bidirectional pump. The n second branch strips 15 are all arranged at the inner side edge of the second main strip 26 and are sequentially arranged along the length direction of the second main strip 26.

The first backbone strip 25 and the second backbone strip 26 are disposed on both sides of the strip-shaped channel 19, respectively. The outer ends of the n first branch strips 16 and the n second branch strips 15 are sequentially and alternately arranged to form a comb-tooth electrode pair structure. The n first branch bars 16 and the n second branch bars 15 form a group two by two to form n unit electrode pairs. The distance between the first branch bar 16 and the second branch bar 15 in one unit electrode pair is smaller than the distance between two adjacent unit electrode pairs. As a preferable technical solution, the distance between the first branch bar 16 and the second branch bar 15 in one unit electrode pair is 0.5mm, and the distance between two adjacent unit electrode pairs is 1 mm. In the same unit electrode, the first branch rib 16 is located on the side of the second branch rib 15 close to the first flow channel hole 13.

The top electrode pair 23 and the first lead-out sheet 17 of the first comb electrode in the bottom electrode pair 24 are connected together to be used as a first input pin of the soft bidirectional pump. The top electrode pair 23 and the second lead-out piece 18 of the second comb-teeth electrode in the bottom electrode pair 24 are connected together to be used as a second input pin of the soft bidirectional pump.

When the first comb-tooth electrode is grounded and the second comb-tooth electrode is at a positive voltage, so that the electric field between the unit electrode pair exceeds 5V/mum, electrons on the first branch bars 16 are transferred to the dielectric liquid in the bar-shaped channels 19, so that electrolyte molecules are charged, the electrolyte molecules are then attracted by the second branch bars 15 with opposite charges, and the charged molecules drag other neutral molecules of the dielectric liquid to move together along the paths of the charged molecules, so that the dielectric liquid in the bar-shaped channels 19 flows along the first flow channel holes 13 to the direction of the second flow channel holes 14, and forward continuous liquid pumping is realized.

When the first comb-tooth electrode is electrified with a positive voltage, the second comb-tooth electrode is grounded, so that the electric field between the unit electrode pair exceeds 5V/mum, electrons on the second branch bars 15 are transferred to the dielectric liquid of the bar-shaped channel 19, electrolyte molecules are charged, the electrolyte molecules are then attracted by the oppositely charged first branch bars 16, and the charged molecules drag other neutral molecules of the dielectric liquid to move together along the path of the charged molecules, so that the dielectric liquid in the bar-shaped channel 19 flows along the second channel holes 14 to the direction of the first channel holes 13, and reverse continuous liquid pumping is realized.

The first channel hole 13 of the top layer 20 of the first soft pump 5 is connected with the first liquid inlet/outlet 2 of the liquid storage tank 1 through a hose (not shown in the figure), and the second channel hole 14 is connected with the first liquid inlet/outlet 7 of the first telescopic pipe 6 through a hose. The first flow passage hole 13 of the top layer 20 on the second soft pump 8 is connected with the second liquid inlet and outlet 4 on the liquid storage tank 1 through a hose, and the second flow passage hole 14 is connected with the second liquid inlet and outlet 10 on the second telescopic pipe 9 through a hose. The liquid storage tank 1, the first soft pump 5, the second soft pump 8, the first telescopic pipe 6 and the second telescopic pipe 9 are filled with dielectric liquid. The first flexible pipe 6 and the second flexible pipe 9 can be filled with liquid and drained of liquid by the forward and reverse electrification of the first flexible pump 5 and the second flexible pump 8.

The two first extension tubes 6 and the second extension tube 9 are both provided with a snakeskin film 12. The snake skin membrane 12 comprises a main body membrane and a snake-like scale. The main body film is connected with the corresponding first extension tube 6 or second extension tube 9; the main body membrane is in a loose state and can stretch and contract along with the telescopic pipe. The outer side surface of the main body membrane is provided with a plurality of snake-like scales. The snake-like scales are made of plastic sheets. The snake-like scales are arranged in a snake-scale shape. The inner ends of the snake-like scales are fixed with the main body membrane. The orientations of the outer ends of all the snake-like scales are consistent. The direction from the outer end to the inner end of the snake-like scale is the advancing direction of the unconstrained soft robot. Except the snake-like scales at the head end of the main body membrane, the inner ends of the other snake-like scales are covered by other snake-like scales. The snake-like scales on the main body membrane are contacted with the ground.

The structure of the snake skin film 12 makes it have anisotropic friction force, so that the unconstrained soft robot has small friction force when moving forward (the forward direction is the direction from the outer end to the inner end of the snake-like scale), and has strong ground holding force when moving backward (during friction, the snake-like scale tends to be turned out and cut into the ground, so that the friction force is increased).

The direction of the liquid storage tank 1 towards the control tank 11 is the advancing direction of the unconstrained soft robot. When the first extension tube 6 and the second extension tube 9 are extended, the control box 11 is pushed forward because the resistance of the snake skin film 12 to retreat is larger than the resistance of the snake skin film to advance; when the first extension tube 6 and the second extension tube 9 are shortened, the liquid storage tank 1 is pulled forwards because the resistance of the snake skin film 12 to retreat is larger than the resistance of the snake skin film to advance, and the continuous advance of the robot can be realized by alternately reciprocating.

The control box 11 is internally provided with a controller and a high-voltage generator. The maximum output voltage of the high voltage generator is greater than 5 kV. Two output pins in the first group of output interfaces of the high-voltage generator are respectively connected with a first input pin and a second input pin of the first soft pump 5. Two output pins in the second group of output interfaces of the high-voltage generator are respectively connected with a first input pin and a second input pin of the second soft pump 8. The control interface of the high-voltage generator is connected with the controller. The controller adopts a singlechip.

The linear forward driving method is specifically as follows:

step one, a second input pin of the first soft pump 5 is connected with a positive voltage, and the first input pin is grounded, so that the forward pump liquid of the first soft pump 5 and the dielectric liquid in the liquid storage tank 1 flow to the first extension pipe 6, and the first extension pipe is extended.

Meanwhile, a second input pin of the second soft pump 8 is connected with a positive voltage, and the first input pin is grounded, so that the forward pump liquid of the second soft pump 8 and the dielectric liquid in the liquid storage tank 1 flow to the second telescopic pipe 9, and the second telescopic pipe is extended.

Under the action of the backward ground-grasping force of the snakeskin film 12, the first telescopic pipe and the second telescopic pipe push the control box 11 to move forward.

And step two, a first input pin of the first soft pump 5 is connected with a positive voltage, and a second input pin is grounded, so that the reverse pump liquid of the first soft pump 5 and the dielectric liquid in the first telescopic pipe 6 flow to the liquid storage tank 1, and the first telescopic pipe is shortened.

Meanwhile, a first input pin of the second soft pump 8 is connected with a positive voltage, and a second input pin is grounded, so that the second soft pump 8 pumps liquid in a reverse direction, and the dielectric liquid in the second telescopic pipe 9 flows to the liquid storage tank 1, so that the second telescopic pipe is shortened.

Under the action of the backward ground-grasping force of the snakeskin film 12, the first telescopic pipe and the second telescopic pipe pull the liquid storage tank 1 to move forward.

And step three, repeatedly executing the step one and the step two to enable the unconstrained soft robot to continuously drive forwards.

The deflection driving method specifically comprises the following steps:

step one, one of the first telescopic pipe 6 and the second telescopic pipe 9 far away from one side of the deflection direction is taken as a working telescopic pipe (namely, if left turning is needed, the telescopic pipe on the right side in the advancing direction is taken as the working telescopic pipe). The soft pump corresponding to the working telescopic pipe is used as a working soft pump.

And step two, a second input pin of the working soft pump is connected with a positive voltage, and the working input pin is grounded, so that the working soft pump pumps liquid in the positive direction, and the dielectric liquid in the liquid storage tank flows to the working telescopic pipe, and the working telescopic pipe extends. Under the action of backward ground-grasping force of the snakeskin film, the working telescopic pipe pushes the control box to deflect towards the target direction.

And step three, the working input pin of the working soft pump is connected with positive voltage, and the second input pin is grounded, so that the working soft pump reversely pumps liquid, and the dielectric liquid in the working telescopic pipe flows to the liquid storage tank, and the working telescopic pipe is shortened. Under the action of the backward ground-grasping force of the snakeskin film, the working telescopic pipe pulls the liquid storage tank to deflect towards the target direction.

Claims

1. An unconstrained soft robot comprises a liquid storage tank, a middle execution mechanism, a first soft pump, a second soft pump, a snakeskin film and a control tank; the method is characterized in that: the top of the liquid storage box is provided with a first liquid inlet and outlet and a second liquid inlet and outlet; the middle actuating mechanism comprises a first telescopic pipe and a second telescopic pipe; a first liquid through opening is formed in the first telescopic pipe; a second liquid through hole is formed in the second telescopic pipe; one end of each of the first telescopic pipe and the second telescopic pipe is fixed with the liquid storage box, and the other end of each of the first telescopic pipe and the second telescopic pipe is fixed with the control box; the first extension tube and the second extension tube are arranged side by side;

the first soft pump and the second soft pump are soft bidirectional pumps; the soft bidirectional pump comprises a top layer, a top electrode pair, a channel layer, a bottom electrode pair and a bottom layer which are sequentially arranged; the middle part of the channel layer is provided with a strip-shaped channel; the two ends of the top layer are respectively provided with a first flow passage hole and a second flow passage hole; the first flow channel hole and the second flow channel hole are respectively communicated with two ends of the strip-shaped channel on the channel layer; the top electrode pair and the bottom electrode pair have the same structure and are in the shape of comb-tooth electrode pairs;

a first flow passage hole in the top layer of the first soft pump is connected with a first liquid inlet and outlet on the liquid storage box, and a second flow passage hole is connected with a first liquid through hole on the first telescopic pipe; a first flow passage hole in the top layer of the second soft pump is connected with a second liquid inlet and outlet in the liquid storage box, and a second flow passage hole is connected with a second liquid through hole in the second telescopic pipe; the liquid storage tank, the first soft pump, the second soft pump, the first telescopic pipe and the second telescopic pipe are all filled with dielectric liquid;

the two first telescopic pipes and the second telescopic pipes are both provided with snakeskin films; the snakeskin film comprises a main body film and a snakelike scale; a plurality of snake-like scales are arranged on the outer side surface of the main body membrane; the inner ends of the snake-like scales are fixed with the main body membrane; the orientations of the outer ends of the snake-like scales are consistent; the snake-like scales on the main body membrane are contacted with the ground.

2. An unconstrained soft robot according to claim 1, wherein: the top electrode pair and the bottom electrode both comprise a first comb-tooth electrode and a second comb-tooth electrode; the first comb electrode comprises a first lead-out sheet, a first trunk strip and n first branch strips; the inner end of the first lead-out sheet is connected with one end of the first trunk strip; the n first branch strips are arranged on the inner side edge of the first main strip and are sequentially arranged along the length direction of the first main strip; the second comb teeth electrode comprises a second lead-out sheet, a second main strip and n second branch strips; the inner end of the second lead-out sheet is connected with one end of the second trunk strip; the n second branch strips are arranged on the inner side edge of the second main strip and are sequentially arranged along the length direction of the second main strip; the first trunk strip and the second trunk strip are respectively arranged on two sides of the strip-shaped channel; the outer ends of the n first branch bars and the n second branch bars are sequentially and alternately arranged; the n first branch strips and the n second branch strips are grouped in pairs to form n unit electrode pairs; the distance between the first branch strip and the second branch strip in one unit electrode pair is smaller than the distance between two adjacent unit electrode pairs; in the same unit electrode, the first branch strip is positioned on one side of the second branch strip close to the first flow channel hole.

3. An unconstrained soft robot according to claim 2, wherein: the distance between the first branch strip and the second branch strip in one unit electrode pair is 0.5mm, and the distance between two adjacent unit electrode pairs is 1 mm.

4. An unconstrained soft robot according to claim 2, wherein: the top electrode pair is connected with a first comb electrode in the bottom electrode pair together and serves as a first input pin of the soft bidirectional pump; and the top electrode pair and a second lead-out piece of a second comb electrode in the bottom electrode pair are connected together to be used as a second input pin of the soft bidirectional pump.

5. An unconstrained soft robot according to claim 4, wherein: the control box is internally provided with a controller and a high-voltage generator; two output pins in a first group of output interfaces of the high-voltage generator are respectively connected with a first input pin and a second input pin of the first soft pump; two output pins in a second group of output interfaces of the high-voltage generator are respectively connected with a first input pin and a second input pin of a second soft pump; the control interface of the high-voltage generator is connected with the controller; the controller adopts a singlechip.

6. An unconstrained soft robot according to claim 1, wherein: the top of the liquid storage tank is also provided with a vent hole; driven wheels are supported on two sides of the liquid storage box and the control box.

7. An unconstrained soft robot according to claim 1, wherein: the first soft pump and the second soft pump are respectively arranged on the first telescopic pipe and the second telescopic pipe.

8. An unconstrained soft robot according to claim 1, wherein: the thickness of the top layer and the bottom layer is 0.4 mm; the thickness of the channel layer is 0.5 mm; the thicknesses of the top electrode pair and the bottom electrode pair are both 30 micrometers; the top layer, the channel layer and the bottom layer are all organic silicon films; the organosilicon is polydimethylsiloxane; the top layer and the bottom layer are both bonded with the channel layer through a silicone adhesive film; both the top electrode pair and the bottom electrode pair are made of stretchable silver materials.

9. An unconstrained soft robot according to claim 1, wherein: the snake-like scales are made of plastic sheets; except the snake-like scales at the head end of the main body membrane, the inner ends of the other snake-like scales are covered by other snake-like scales.

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

the linear driving method is concretely as follows:

step one, the first soft pump is electrified in a forward direction, so that the dielectric liquid in the liquid storage tank flows to the first telescopic pipe when the first soft pump pumps liquid in the forward direction, and the first telescopic pipe is extended;

meanwhile, the second soft pump is electrified reversely, so that the dielectric liquid in the liquid storage tank flows to the second telescopic pipe by the forward pump liquid of the second soft pump, and the second telescopic pipe is extended;

under the action of backward ground-grasping force of the snakeskin film, the first extension tube and the second extension tube push the control box to move forward; the direction from the outer end to the inner end of the snake-like scale is the advancing direction;

step two, the first soft pump is electrified reversely, so that the dielectric liquid in the first telescopic pipe and the reverse pump liquid of the first soft pump flow to the liquid storage tank, and the first telescopic pipe is shortened;

meanwhile, the second flexible pump is electrified reversely, so that the dielectric liquid in the second flexible pipe flows to the liquid storage tank by the reverse liquid pumping of the second flexible pump, and the second flexible pipe is shortened;

under the action of the backward ground-grasping force of the snakeskin film, the first telescopic pipe and the second telescopic pipe pull the liquid storage tank to move forward;

step three, repeatedly executing the step one and the step two to realize continuous advancing;

the deflection driving method specifically comprises the following steps:

step one, one of the first telescopic pipe and the second telescopic pipe far away from one side of the deflection direction is taken as a working telescopic pipe; a soft pump corresponding to the working telescopic pipe is used as a working soft pump;

step two, the working soft pump is powered on in the forward direction, so that the dielectric liquid in the working soft pump and the liquid storage tank flows to the working telescopic pipe in the forward direction, and the working telescopic pipe is extended; under the action of backward ground-grasping force of the snakeskin film, the working telescopic pipe pushes the control box to deflect towards the target direction;

step three, the working soft pump is reversely electrified, so that the dielectric liquid in the working telescopic pipe flows to the liquid storage tank by reversely pumping the liquid of the working soft pump, and the working telescopic pipe is shortened; under the action of backward ground-grasping force of the snakeskin film, the working telescopic pipe pulls the liquid storage tank to deflect towards the target direction;