A inchworm-like robot with a large working space and a series-parallel hybrid mechanism

Abstract

The present invention provides a large-working-space inchworm-like robot with a serial-parallel hybrid mechanism, which solves the shortcomings of the existing high requirements on the robot's structural design and motion gait control, and brings difficulties to the continuous or further miniaturization of the robot. The present invention provides a new type of serial-parallel hybrid mechanism type inchworm-like robot, which adopts a 5-degree-of-freedom serial-parallel mechanism as a driving mechanism, wherein the parallel mechanism has the ability to rotate on a hemispherical surface; the robot has high maneuverability, can simultaneously realize the "Ω" motion and deflection motion of the inchworm, can not only move on cracked surfaces and rough surfaces, but also cross some lower obstacles; it has the advantages of strong controllability and large load capacity of the parallel mechanism, and the advantage of a large working space of the serial mechanism.

Description

Technical Field

[0001] The invention belongs to the technical field of robots, and in particular relates to an inchworm-like robot with a large working space and a series-parallel hybrid mechanism. Background Art

[0002] Highly maneuverable small robots have a wide range of application needs in post-disaster search, endoscopic surgery, oil and gas pipeline inspections and other fields.

[0003] The peristaltic movement of the inchworm is faster than the forward movement of earthworms through radial extension and contraction of body segments. The feet at the head and tail enable the inchworm to move on plant branches, cracked surfaces and rough surfaces, and to cross some low obstacles. At the same time, the high maneuverability and flexibility of the inchworm's movement can also help it cope with some complex and harsh environments with ease. As a bionic prototype, the inchworm has been widely studied.

[0004] At present, in order to simulate the movement mode of the inchworm, many technical solutions have been proposed, such as the W-Climbot robot composed of five serial mechanism modules and two suction modules installed at both ends, and the inchworm-like robot composed of parallel mechanism retractable actuators used for blade maintenance of offshore wind power generation systems. Most of these inchworm-like robots are composed of serial mechanisms or parallel mechanisms.

[0005] Chinese patent CN107830307B proposes a highly maneuverable inchworm-like creeping robot composed of four drive mechanisms connected in series and in series with a tail. The patent proposes a robot trunk design with multiple redundant degrees of freedom, which enables the robot to achieve multiple motion modes such as telescoping, deflection, and pitching, and has good controllability and motion flexibility. The modular design enables the robot to have expandable degrees of freedom and improves environmental adaptability; the multi-segment multi-drive mechanism design method can improve the robustness of the robot when any of the drive mechanisms fails; however, when the robot of this structure performs inchworm-like Ω motion, the drive motor of the drive segment connected to the tail is required to have a larger drive torque than other segments, which puts high demands on the robot's structural design and motion gait control, and also brings difficulties to the continuous or further miniaturization of the robot. If it cannot be miniaturized, it will also encounter certain difficulties in actual situations such as disaster relief, medical rehabilitation, and equipment maintenance. Summary of the invention

[0006] The purpose of the present invention is to solve the shortcomings of the existing high requirements on robot structure design and motion gait control, which bring difficulties to the continuous or further miniaturization of robots, and provide a large working space series-parallel hybrid mechanism inchworm-like robot.

[0007] The concept of the present invention is:

[0008] Most of the current inchworm-like robots are composed of serial mechanisms or parallel mechanisms, which have limitations in terms of structural rigidity, position accuracy or workspace size. To simulate the body structure and movement mode of the inchworm, the serial mechanism is used to expand the workspace, while the parallel mechanism is used to improve the mobility and control stability of the mechanism. Based on this, the present invention provides an inchworm-like robot with a serial-parallel hybrid mechanism that is easy to miniaturize and has high mobility, which can reduce the torque requirements of the motor of the parallel drive structure.

[0009] To achieve the above purpose, the technical solution provided by the present invention is:

[0010] A large working space serial-parallel hybrid mechanism anti-inchworm robot, comprising a head, a trunk and a tail connected in sequence; the special features thereof are:

[0011] The internal skeletons of the head and tail are both L-shaped structures. The head includes an outer shell and an L-shaped support and counterweight frame, and the tail includes an outer shell, a power supply, a controller, and an L-shaped support and counterweight frame. The L-shaped support and counterweight frames of the head and tail are symmetrically arranged. The bottom surfaces of the outer shells of the head and tail are variable anchoring structures.

[0012] The inside of the trunk is a driving mechanism composed of a mixed parallel mechanism and a series mechanism from the tail to the head, and the outside is a flexible sleeve-type skin (that is, the flexible sleeve-type skin is covered on the outside of the driving mechanism), and the two ends of the flexible sleeve-type skin are respectively connected to the outer shells of the head and the tail;

[0013] The parallel mechanism is a 3-DOF mechanism, including a Y-shaped base, a Y-shaped motion platform, and three sets of kinematic chain components arranged in parallel between the Y-shaped base and the Y-shaped motion platform (relatively speaking, the three kinematic chain components are symmetrically arranged);

[0014] The Y-shaped base is fixedly connected to the tail (i.e., the Y-shaped base is mounted on the L-shaped counterweight support frame of the tail), and includes a first Y-shaped body and three arms arranged thereon; the planes where the three arms are located intersect on the same straight line, the straight line is perpendicular to the first Y-shaped body, and the three planes form an angle of 120° between each other; wherein, one arm is located directly above the ground plane, and the other two arms are located on both sides below the arm at an angle of 120° to the arm;

[0015] The Y-shaped motion platform includes a second Y-shaped body and three pin hole seats arranged thereon; the planes where the three pin hole seats are located intersect on the same straight line, the straight line is perpendicular to the second Y-shaped body, and the three planes form an angle of 120° between each other; the three pin hole seats are arranged one by one corresponding to the three arm rods;

[0016] Each group of the kinematic chain components includes a driving motor and four connecting rods; wherein the four connecting rods are connected in sequence to form three groups of rotating pairs, and the rotating axes of the three groups of rotating pairs intersect at one point; the outer end of the connecting rod located at the head is connected to one of the pin hole seats on the Y-shaped motion platform through a rotating pair; the driving motor is installed on one of the arm rods of the Y-shaped base, and its output shaft is connected to the connecting rod located at the tail; the rotating axis of the rotating pair at the outer end of the head connecting rod, the rotating axis of the rotating pair between the four connecting rods, and the output shaft of the driving motor are perpendicular to each other; the connecting rod at the tail is driven to rotate by the driving motor, thereby driving the kinematic chain to rotate relative to the Y-shaped base, thereby controlling the Y-shaped operating platform to perform pitch, roll, translation and telescopic movements;

[0017] The series mechanism comprises a first straight connecting rod and a second straight connecting rod of two unequal lengths;

[0018] Among them, the tail end of the first straight link is fixedly connected to the Y-shaped motion platform, the head end is connected to the tail end of the second straight link through a rotating pair, the head end of the second straight link is connected to the head through a rotating pair, and driving motors are installed at both rotating pairs, so that the two straight links can rotate around the rotating pair, thereby lifting the trunk and head upward; it can be understood that the head end of the first straight link is installed with a driving motor to control the second straight link to rotate around the rotating pair, and the head end of the second straight link is also installed with a driving motor to control the head to rotate around the rotating pair.

[0019] Further, the straight line where the planes where the three arms are located intersect passes through the geometric center of the first Y-shaped body;

[0020] The three arms are provided with mounting holes for mounting the parallel mechanism driving motor and through holes for passing the output shaft of the parallel mechanism driving motor, and the centers of the through holes on the three arms are on the same circumference.

[0021] Furthermore, the straight line where the planes where the three pin hole seats are located intersect passes through the geometric center of the second Y-shaped body, and the centers of the pin holes on the three pin hole seats are on the same circumference.

[0022] Furthermore, in order to facilitate the passage of wires and save space, a first circular hole is provided at the geometric center of the first Y-shaped body; a second circular hole is provided at the geometric center of the second Y-shaped body; the middle parts of the first straight link and the second straight link are both hollowed out. This hollow design not only reduces the mass of the entire trunk, but also allows the center of gravity of the robot structure to shift to the tail as much as possible, thereby enhancing the stability of the robot's movement. It is also more in line with the movement law of the inchworm in nature that uses its thick tail to anchor itself to the ground or clamp itself on a branch.

[0023] Furthermore, the rotating pair of the series mechanism includes a U-shaped structure and a short chain rod, that is, this structure is used as a rotating pair between the first straight link and the second straight link, and between the second straight link and the head; the structure of the rotating pair is simple and reliable, and the rotation is smooth.

[0024] The U-shaped structure is arranged at the head end of the straight connecting rod (referring to the first straight connecting rod and the second straight connecting rod), and a first through hole is arranged on the side wall thereof;

[0025] A second through hole coaxial with the first through hole and having a shape matching the output shaft mechanism of the drive motor is provided on the tail end of the short connecting rod; the head end of the short connecting rod is connected to the tail end or head end of the second straight connecting rod (the head end of the short connecting rod between the two straight connecting rods is fixedly connected to the second straight connecting rod, and the head end of the short connecting rod between the second straight connecting rod and the head end is fixedly connected to the L-shaped counterweight support frame of the head end);

[0026] The output shaft of the driving motor passes through the first through hole and the second through hole and is fixedly connected to the short link rod, and is used to drive the short link rod to rotate relative to the first straight link rod or the second straight link rod.

[0027] Furthermore, the revolving pairs between the four connecting rods in the parallel mechanism are connected by pins.

[0028] Furthermore, the variable anchoring structure specifically refers to: the middle part of the bottom surface of the shell of the head and the tail is selected with a friction pad or a suction cup according to the application environment, and the two ends (i.e., the head and tail sections) are arc-shaped main body structures without friction pads or suction cups. The design of this part makes the friction force with the contact surface as small as possible when the head and the tail are in a tilted state, thereby increasing the difference in friction force between the head and the tail and the contact surface when the robot performs certain movements, achieving the effect of variable friction; the area of ​​the friction pad can be increased or decreased according to the holding force required for the movement of the robot.

[0029] Further, in an initial state, the length of the second straight connecting rod is equal to the sum of the axial lengths of the first straight connecting rod and the parallel mechanism.

[0030] Furthermore, the overall mass of the tail is greater than the overall mass of the head, that is, the mass of the tail L-shaped support frame can be greater than the mass of the head L-shaped support frame, which mainly allows the center of gravity of the entire structure to be as close to the tail as possible when the robot completes a motion state such as raising its head, so that it has better stability and does not fall forward. The head and tail shells are symmetrical in structure and can completely wrap the L-shaped support frame, power supply and controller, thereby saving the internal space of the robot.

[0031] Furthermore, the parallel mechanism is made of aviation aluminum; compared with most metal materials, this material is lighter and can provide sufficient structural strength and motion accuracy when the robot needs to complete motion gaits such as raising its head;

[0032] The two straight connecting rods and the shells of the head and tail are all made of polylactic acid (biodegradable material polylactic acid), which is a polyester polymer that has good tensile strength and heat resistance while being light and safe, and thus has better mechanical and physical properties;

[0033] The flexible sleeve skin is bonded to the outer shells of the head and tail with AB glue. The flexible sleeve skin can expand and contract like a spring, wrapping the entire robot connecting rod and driving part inside. The skin makes the robot look similar to the body of an inchworm while protecting the interior of the robot from the influence of external environment such as fluid and dust.

[0034] The friction pad is made of silicone and is used to provide sufficiently large friction during the movement of the robot, thereby enhancing the movement effect of the robot on a rough surface.

[0035] The suction cup is a vacuum suction cup or an electromagnetic suction cup; when the robot moves on a smooth contact surface (such as glass, etc.), the vacuum suction cup can be used; when the robot moves on a metal surface, the electromagnetic suction cup can be used.

[0036] The advantages of the present invention are:

[0037] 1. The present invention provides a novel hybrid serial-parallel mechanism type inchworm-like robot. The robot adopts a 5-DOF serial-parallel mechanism as a driving mechanism, wherein the parallel mechanism has a hemispherical rotation capability through the design of three transmission chains. The robot has high mobility and can simultaneously realize the "Ω" motion and deflection motion modes of the inchworm. It can not only move on cracked surfaces and rough surfaces, but also cross some lower obstacles. It has the advantages of strong controllability and large load capacity of the parallel mechanism, and the advantage of large working space of the serial mechanism.

[0038] 2. The robot of the present invention not only reduces the size of the entire mechanism, but also makes structural adjustments to the connecting rods in the motion chain. The entire motion chain is constructed by four rotating matching connecting rods, and the rotating sub-axes between the four connecting rods intersect at one point. The rotating sub-axes at the outer end of the head connecting rod, the rotating sub-axes between the four connecting rods, and the output shaft of the driving motor are perpendicular to each other, which not only expands the motion range of the mechanism, but also the connecting rods at the head and tail ends are connected to the second connecting rod through a rotating pair, which also leaves a margin for telescopic motion, greatly improving the motion flexibility of the entire motion chain, and having low requirements for synchronization between the connecting rods and low requirements for processing and manufacturing precision, which is easy to implement; a circular ring (i.e., a middle through hole) structure design is added to the middle of the "Y"-shaped structure of the base and the motion platform to facilitate the passage of the power supply and controller wires through it and save space.

[0039] 4. The tail of the robot of the present invention includes a power supply and a controller module, so the robot can be automatically controlled.

[0040] 5. The bottom of the robot's head and tail shells are both variable anchoring structures. Friction pads or suction cups can be selected according to the application scenario, allowing the robot to move on different types of surfaces, with high movement form diversity and high softness.

[0041] 6. The straight connecting rod adopts a hollow middle design, which reduces the mass of this part and reduces the torque required to lift this part, so that a drive motor with smaller volume and torque can be selected.

[0042] 7. The flexible sleeve-like skin on the outside of the robot's trunk can protect the internal driving parts from the influence of external environments such as fluids and dust.

[0043] 8. The robot has a wide range of applications. It can be used for post-disaster rescue work in natural disasters such as earthquakes, landslides, fires, and floods, and to assist in finding people trapped in debris and obstacles; it can be used in medical surgical endoscopic surgery, body diagnosis, and stone removal, to inspect smaller pipes such as the esophagus and intestines, to help transport different types of small units, and to remove blood plaques and stones from different parts of the body; it can be used in pipeline inspection and maintenance scenarios in the oil and gas industry, and can move and climb in pipelines to inspect U, V, L and other types of joint pipelines; it can be used in the aerospace field for space exploration and alien detection, to go deep into alien rocks or beneath the surface for search and exploration. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the inchworm-like robot with a series-parallel hybrid mechanism of the present invention.

[0045] Figure 2 A cross-sectional view of the internal components of the robot's drive mechanism.

[0046] Figure 3 This is a schematic diagram of the exploded structure of the head and tail parts of the robot.

[0047] Figure 4 This is a schematic diagram of the exploded structure of the parallel mechanism part of the robot.

[0048] Figure 5 This is the overall schematic structure diagram of the parallel mechanism part of the robot.

[0049] Figure 6 This is a schematic diagram of the exploded structure of the robot's serial mechanism.

[0050] Figure 7 It is a structural diagram of the robot "Ω" motion state example.

[0051] Figure 8 Schematic diagram of the structure of an example of the robot cantilever motion state.

[0052] Fig. 9 It is a structural diagram of an example of the robot's deflection motion state. DETAILED DESCRIPTION

[0053] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0054] Specific directional terms are used in the following description for convenience only and are referenced to the corresponding drawings. They are not to be construed as limitations of the present invention. When the defined direction of the drawings changes, the directions indicated by these terms should be interpreted as corresponding different directions.

[0055] The inchworm-like robot with a series-parallel hybrid mechanism provided by the present invention is as follows: Figure 1 and Figure 2 As shown in the figure, its main structure consists of a head 1, a tail 2 and a trunk 3. The head includes a shell and an L-shaped support and counterweight frame, and the tail includes a shell, a power supply, a controller and an L-shaped support and counterweight frame, which are responsible for the autonomous control of the robot. The trunk consists of a parallel drive mechanism 3A, a series drive mechanism 3B and 3C, and a flexible sleeve skin 3D. The flexible skin will shrink when squeezed, which not only makes the trunk of the robot similar to an inchworm, but also protects the internal drive part from the influence of external environment such as fluid and dust.

[0056] The head and tail structure is as follows Figure 3 As shown, the bottom surface is a variable anchoring structure, and a friction pad of a certain cross-sectional area and made of silicone material is attached to the middle 1A and 2A of the bottom surface to contact the rough surface. There is a section 1B, 1C, 2B and 2C without a friction pad at both ends of the bottom surface of the head and tail; the area of ​​the friction pad at the middle 1A and 2A of the bottom surface can be increased or decreased according to the holding force required for the movement of the robot, and of course, the corresponding material can be selected according to the needs. When the robot moves on a smooth contact surface (such as glass, etc.), the friction pad can be replaced by a vacuum suction cup; when the robot moves on a metal surface, the friction pad can be replaced by an electromagnetic suction cup. Among them, the mass of the tail counterweight is greater than the mass of the head counterweight.

[0057] The detailed structure diagram of the parallel mechanism is given by Figure 4 and Figure 5As shown. The parallel mechanism includes a Y-shaped base, a Y-shaped motion platform and three groups of motion chain components arranged between the base and the motion platform. The Y-shaped base 3A1 includes a first Y-shaped body and three arms arranged thereon; the planes where the three arms are located intersect on the same straight line, which is perpendicular to the first Y-shaped body and passes through the geometric center of the first Y-shaped body; the three planes are at an angle of 120° between each other; among them, one arm is located directly above the ground plane, and the other two arms are at an angle of 120° to the arm and are located on both sides below it; the three arms are provided with mounting holes for installing the parallel mechanism drive motor and through holes for passing the output shaft of the parallel mechanism drive motor, and the centers of the through holes on the three arms are on the same circumference; a first circular hole is provided at the geometric center of the first Y-shaped body, and the area of ​​the first circular hole is large enough to allow the wires of the power supply and the controller to pass through it. The Y-shaped motion platform includes a second Y-shaped body and three pin hole seats arranged thereon; the planes where the three pin hole seats are located intersect on the same straight line, which is perpendicular to the second Y-shaped body and passes through the geometric center of the second Y-shaped body, and the three planes are at an angle of 120° between each other, and the centers of the pin holes on the three pin hole seats are on the same circumference; the three pin hole seats are arranged in a one-to-one correspondence with the three arm rods; a second circular hole is arranged at the geometric center of the second Y-shaped body, and the area of ​​the second circular hole is large enough to allow the wires of the power supply and the controller to pass through it. Figure 4 The suffixes a, b, and c in the labels correspond to three identical kinematic chain components in the parallel mechanism, respectively; each kinematic chain structure includes a drive motor and four connecting rods. The following description takes the structure of one set of kinematic chain components as an example, omitting the suffixes.

[0058] The driving motor 3A3 is fixed to the Y-shaped base 3A1 by two screws, and the output shaft passes through the coaxial through hole of the arm in the base 3A1. The through hole on the side of the connecting rod 3A4 has the same cross-sectional shape as the output shaft of the driving motor, and the output shaft of the driving motor passes through the through hole on the side of the connecting rod 3A4 and is fixedly connected to the connecting rod 3A4. When the output shaft of the driving motor rotates, it can drive the connecting rod 3A4 to rotate relative to the Y-shaped base 3A1, and then drive the entire kinematic chain assembly to rotate relative to the Y-shaped base 3A1.

[0059] The connecting rods 3A4 and 3A5, the connecting rods 3A5 and 3A6, the connecting rods 3A6 and 3A7, and the connecting rod 3A7 and the Y-type motion platform 3A2 are all connected by a revolute pair. The two connecting rods that need to be connected by a revolute pair each have a pin hole at one end, and a pin passes through the pin hole, so that the two connecting rods are connected at one end and can rotate and cooperate to form a revolute pair. The three groups of revolute pair shafts between the four connecting rods intersect at one point. For the revolute pair shaft at the outer end of the head connecting rod, the revolute pair shafts between the four connecting rods, and the output shaft of the driving motor, the adjacent shafts are perpendicular to each other; the driving motor drives the connecting rod at the tail to rotate, and then drives the motion chain to rotate relative to the Y-type base, and then controls the Y-type operating platform to perform pitch, roll and translation telescopic movements.

[0060] The detailed structure diagram of the series mechanism is given by Figure 6 As shown. The series mechanism consists of two straight connecting rods of unequal lengths and two driving motors. In the initial state, the length of the second straight connecting rod is equal to the sum of the axial lengths of the first straight connecting rod and the parallel mechanism. One end of the first straight connecting rod 3B1 is a circular ring structure, which is fixed to the Y-shaped motion platform 3A2 by three screws. The driving motor 3B2 is fixed to the other end of the first straight connecting rod 3B1 by two screws, and the output shaft passes through the through hole on the side of the U-shaped structure of the first straight connecting rod 3B1. The through hole on the side of the first short connecting rod 3B3 has the same cross-sectional shape as the output shaft of the driving motor. The output shaft of the driving motor passes through the through hole on the side of the first short connecting rod 3B3 and is fixedly connected to it. At the same time, the first short connecting rod 3B3 is fixed to the second straight connecting rod 3C1 by screws. The connection method of the second straight connecting rod 3C1, the driving motor 3C2, and the second short connecting rod 3C3 is the same as the connection method of the first straight connecting rod 3B1, the driving motor 3B2, and the first short connecting rod 3B3; the head end of the second short connecting rod 3C3 is fixed to the head 1 by screws.

[0061] Figure 7 The structural diagram of the robot's "Ω" motion state example is given. In the initial state, the robot's head, tail and trunk are all in a straight state, with the head and tail fixed on the horizontal plane, and the trunk not in contact with the horizontal plane. The robot relies on the drive motor of the parallel mechanism to slightly lift the tail for a distance, while the head is kept anchored by the static friction between the bottom friction pad and the horizontal plane. Under the joint action of all drive motors, the robot lifts the trunk to the "Ω" shape, and then puts the tail on the horizontal plane, so that the friction pad at the bottom of the tail is in full contact with the horizontal plane, thus achieving the "Ω" motion state.

[0062] Figure 8The structural diagram of the robot cantilever motion state example is given. Based on the "Ω" motion state, the tail is anchored on the horizontal plane through the bottom friction pad, and the robot lifts the trunk through the driving motor of the trunk straight link, so that the two straight links are in a straight line with the head, thus achieving the cantilever motion state.

[0063] Fig. 9 The structural schematic diagram of the robot's deflection motion state example is given. Deflection motion can occur when the robot is in the straight state, "Ω" state, and cantilever state. Here, the straight state is used as an example. The tail of the robot is in contact with the horizontal plane through the bottom friction pad to maintain the anchor state, while the head is separated from the horizontal plane. The driving motor of the parallel mechanism performs deflection motion to change the direction of the head, and then the head is lowered until it is completely in contact with the horizontal plane, thereby achieving the deflection motion state.

[0064] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should be included in the protection scope of the present invention.

Claims

1. A large working space serial-parallel hybrid mechanism inchworm robot, comprising a head, a trunk and a tail connected in sequence; characterized in that: The internal frames of the head and tail are both L-shaped structures, and the bottom surfaces of the shells are provided with variable anchoring structures; The inside of the trunk is a driving mechanism composed of a mixed parallel mechanism and a series mechanism from the tail to the head, and the outside is a flexible sleeve-type skin, and the two ends of the flexible sleeve-type skin are respectively connected to the outer shells of the head and the tail; The parallel mechanism is a 3-DOF mechanism, comprising a Y-shaped base, a Y-shaped motion platform, and three sets of kinematic chain components arranged in parallel between the Y-shaped base and the Y-shaped motion platform; The Y-shaped base is fixedly connected to the tail, and includes a first Y-shaped body and three arm rods arranged thereon; the planes where the three arm rods are located intersect on the same straight line, the straight line is perpendicular to the first Y-shaped body, and the three planes form an angle of 120° between each other; The Y-shaped motion platform includes a second Y-shaped body and three pin hole seats arranged thereon; the planes where the three pin hole seats are located intersect on the same straight line, the straight line is perpendicular to the second Y-shaped body, and the three planes form an angle of 120° between each other; Each group of the kinematic chain components includes a driving motor and four connecting rods; wherein the four connecting rods are connected in sequence to form three groups of rotating pairs, and the rotating axes of the three groups of rotating pairs intersect at one point; the outer end of the connecting rod located at the head is connected to one of the pin hole seats on the Y-shaped motion platform through a rotating pair; the driving motor is installed on one of the arm rods of the Y-shaped base, and its output shaft is connected to the connecting rod located at the tail; the rotating axis of the rotating pair at the outer end of the head connecting rod, the rotating axis of the rotating pair between the four connecting rods, and the output shaft of the driving motor are perpendicular to each other; the connecting rod at the tail is driven to rotate by the driving motor, and then the kinematic chain is driven to rotate relative to the Y-shaped base, and the Y-shaped motion platform is controlled to perform pitch, roll, translation and telescopic movements; The series mechanism comprises a first straight connecting rod and a second straight connecting rod of two unequal lengths; Among them, the tail end of the first straight link is fixedly connected to the Y-shaped motion platform, the head end is connected to the tail end of the second straight link through a rotating pair, the head end of the second straight link is connected to the head through a rotating pair, and driving motors are installed at both rotating pairs, so that the two straight links can rotate around the rotating pairs, thereby lifting the trunk and head upward.

2. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 1, characterized in that: The straight line where the planes where the three arms are located intersect passes through the geometric center of the first Y-shaped body; The three arms are provided with mounting holes for mounting the parallel mechanism driving motor and through holes for passing the output shaft of the parallel mechanism driving motor, and the centers of the through holes on the three arms are on the same circumference.

3. The inchworm-like robot with a large working space serial-parallel hybrid mechanism according to claim 1 or 2, characterized in that: The straight line where the planes where the three pin hole seats are located intersect passes through the geometric center of the second Y-shaped body, and the centers of the pin holes on the three pin hole seats are on the same circumference.

4. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 3, characterized in that: A first circular hole is provided at the geometric center of the first Y-shaped body; A second circular hole is provided at the geometric center of the second Y-shaped body; The middle parts of the first straight link and the second straight link are both hollowed out.

5. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 4, characterized in that: The revolving pair of the series mechanism includes a U-shaped structure and a short chain rod; The U-shaped structure is arranged at the head end of the straight connecting rod, and a first through hole is arranged on the side wall thereof; A second through hole coaxial with the first through hole and having a shape matching the output shaft mechanism of the drive motor is provided on the tail end of the short connecting rod; the head end of the short connecting rod is connected to the tail end or head end of the second straight connecting rod; The output shaft of the driving motor passes through the first through hole and the second through hole and is connected to the short link rod, so as to drive the short link rod to rotate relative to the first straight link rod or the second straight link rod.

6. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 5, characterized in that: The revolving pairs among the four connecting rods in the parallel mechanism are connected by pins.

7. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 6, characterized in that: The variable anchoring structure specifically refers to: the middle of the bottom surface of the head and tail shells are selected with friction pads or suction cups according to the application environment, and the two ends are arc-shaped body structures without friction pads or suction cups.

8. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 7, characterized in that: In an initial state, the length of the second straight link is equal to the sum of the axial lengths of the first straight link and the parallel mechanism.

9. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 8, characterized in that: The overall mass of the tail is greater than the overall mass of the head.

10. The large working space serial-parallel hybrid mechanism inchworm-like robot according to claim 9, characterized in that: The parallel mechanism is made of aviation aluminum; The two straight connecting rods and the shells of the head and tail are all made of polylactic acid; The flexible sleeve-type skin is bonded to the outer shells of the head and tail by using AB glue; The friction pad is made of silicone; The suction cup is a vacuum suction cup or an electromagnetic suction cup.

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