Low-degree-of-freedom cable-strut hybrid robot for spraying operation

Abstract

The invention discloses a low-degree-of-freedom cable-strut hybrid robot for spraying operation. The low-degree-of-freedom cable-strut hybrid robot comprises a bottom plate, a platform base and a flexible cable driving mechanism are arranged on the bottom plate, an actuator module is arranged on the platform base, the actuator module comprises at least one set of low-degree-of-freedom parallel mechanism, and the flexible cable driving mechanism outputs multiple sets of flexible cables to the actuator module. According to the invention, the working space and the loading capacity of the robot are increased by adopting a cable-rod parallel connection mode, so that the robot can adapt to various irregular workpieces, and the interference of the rope and the interference between the rope and the workpieces can be avoided by the winding device. The characteristics of high rigidity and high precision of a parallel platform are reserved, the characteristics of large load ratio, large working space and simple structure of rope driving are also reserved, the load ratio can be increased, the upper platform can move more flexibly, and the upper platform can cross a narrow gap interval and can be fully utilized in a narrow space; therefore, accurate control over the end effector is achieved, and telescopic tension is effectively controlled.

Description

Technical Field

[0001] The invention relates to the field of robots with low degrees of freedom, in particular to a cable-rod hybrid robot with low degrees of freedom for spraying operations. Background Art

[0002] As an important representative of the development of artificial intelligence technology, robots play an important role in both industry and life. Among them, rigid parallel robots have been receiving attention recently due to their advantages such as no cumulative error, good dynamic response, and large carrying capacity. However, their structure is too complex, and interference between different branches is likely to occur, which limits the range of motion of the mechanism. In addition, their spatial motion ability is poor, and they are more likely to have singular configurations, which ultimately leads to sudden changes in the freedom and force of the mechanism, causing abnormal movement or even damage to the mechanism. In addition, the rigid rod itself has a large mass, so that the maximum speed of the end of the mechanism during movement cannot meet the requirements of high-speed movement. At the same time, rigid robots also have safety issues in interaction with operators and working environment.

[0003] With the development of robots, soft robots can achieve complex deformation and obstacle avoidance movements, and adapt to the environment through their own deformation. In the field of security or military reconnaissance, a small and stealthy robot is needed to perform monitoring tasks; in the field of high-altitude operations, a light-weight, flexible and safe robot is needed to assist or replace humans; in rescue and search, when facing a variety of uncertain environments, a small and flexible robot is needed to search and rescue lives in ruins. For example, the Chinese invention patent with application number CN202211022783.4: a plant-like growth soft robot that can achieve stiffness and steering decoupling. The robot can achieve real-time active steering of the plant-like soft growth robot, and can also achieve stiffness and steering decoupling to improve the end load capacity. For example, the Chinese invention patent with application number CN202110676165.0: a pneumatically driven snake-like soft robot. The snake-like soft robot has a simple structure and is easy to make, and can achieve spatial bending motion with two degrees of freedom: left and right yaw and up and down pitch. However, due to the material and structural characteristics of soft robots, they have low stability and repeatability when performing precise tasks, while also greatly reducing their own stiffness.

[0004] Therefore, the present invention proposes a parallel mechanism driven by a hybrid of ropes and rigid rods, which can use gravity, buoyancy or elastic force to maintain all rope tensions. Generally, gravity and buoyancy are naturally generated, while elastic force is usually provided by passive limbs. Most passive limbs provide rope tension in the robot by placing telescopic rods and springs between the moving platform and the base platform. The cable-rod hybrid structure can not only overcome the problems of large mass, high inertia and rod interference of pure rigid rod mechanisms, but also improve the stiffness problem of pure flexible rope mechanisms. At the same time, a configuration with fewer degrees of freedom is adopted to simplify its kinematic and dynamic models, reduce the control difficulty, and reduce the coupling between different branches. It can meet most industrial operations while reducing the complexity of the mechanism and production costs. Summary of the invention

[0005] The present invention provides a cable-rod hybrid robot with few degrees of freedom for spraying operations, so as to solve the problems of easy interference, low rigidity and low load-bearing capacity existing in the prior art.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A low-degree-of-freedom cable-rod hybrid robot for spraying operations, comprising a base plate, a platform base (2) being provided on the base plate, an actuator module (1) being provided on the platform base (2), and a flexible cable driving mechanism (3) being provided on the base plate;

[0008] The actuator module (1) comprises at least one group of low-degree-of-freedom parallel mechanisms, wherein the low-degree-of-freedom parallel mechanisms comprise an upper platform (13), a lower platform (11), and a PP branch (14), an RSR branch (12), a first URU branch (15), and a second URU branch (16) connected between the upper and lower platforms, wherein the PP branch (14) is located at the center of the upper and lower platforms, and the RSR branch (12), the first URU branch (15), and the second URU branch (16) are distributed around the PP branch (12);

[0009] When the actuator module (1) includes only one set of parallel mechanisms with a small degree of freedom, the lower platform (11) in the parallel mechanism with a small degree of freedom is fixed to the platform base (2);

[0010] When the actuator module (1) includes a plurality of groups of small-degree-of-freedom parallel mechanisms, the groups of small-degree-of-freedom parallel mechanisms are distributed in a straight line, and the lower platform of one group of small-degree-of-freedom parallel mechanisms among adjacent small-degree-of-freedom parallel mechanisms serves as the upper platform of another group of small-degree-of-freedom parallel mechanisms, and the lower platform of the first small-degree-of-freedom parallel mechanism is fixed on the platform base (2);

[0011] The flexible cable driving mechanism (3) outputs a plurality of flexible cables to the actuator module (1); when the actuator module (1) includes only one group of parallel mechanisms with fewer degrees of freedom, each group of flexible cables passes through the lower platform (11) of the parallel mechanism with fewer degrees of freedom and is then fixedly connected to the upper platform (13); when the actuator module (1) includes multiple groups of parallel mechanisms with fewer degrees of freedom, each group of flexible cables passes through the remaining upper and lower platforms except the upper platform of the last parallel mechanism with fewer degrees of freedom and is then fixedly connected to the upper platform of the last parallel mechanism with fewer degrees of freedom.

[0012] Furthermore, in the low-freedom parallel mechanism, the PP branch (14) comprises an S ball joint A (141), a sleeve (142), a light rod (143), an S ball joint B (144), and a spring (145); one axial end of the sleeve (142) is a barrel opening, and the other axial end is a closed end; the light rod (143) is partially slidably installed in the sleeve (142) to form a sliding pair; one end of the light rod (143) passes through the barrel opening of the sleeve (142), and the light rod (143) is located in the sleeve (142). ) one end outside the tube mouth is connected to the upper platform (13) through the S ball joint B (144), and the closed end of the sleeve (142) is connected to the lower platform (11) through the S ball joint A (141); the spring (145) is sleeved on the portion of the light rod (143) located outside the tube mouth of the sleeve (142), one end of the spring (145) passes through the tube mouth of the sleeve (142) and is fixed in the sleeve (142), and the other end of the spring (145) is fixed to the portion of the light rod (143) located outside the tube mouth of the sleeve (142).

[0013] Furthermore, in the low-degree-of-freedom parallel mechanism, the RSR branch (12) includes an R rotating joint A (121), an S ball joint C (122), a connecting rod A (123), an R rotating joint B (124), and a connecting rod B (125); one end of the connecting rod B (125) is connected to the lower platform (11) through the R rotating joint A (121), the other end of the connecting rod B (125) is connected to one end of the connecting rod A (123) through the S ball joint C (122), and the other end of the connecting rod A (123) is connected to the upper platform (13) through the R rotating joint B (124).

[0014] Furthermore, in the low-degree-of-freedom parallel mechanism, the first URU branch (15) and the second URU branch (16) have the same structure, both including a U-rotation joint A (151), an R-rotation joint C (152), a connecting rod C (153), a U-rotation joint B (154), and a connecting rod D (155); one end of the connecting rod D (155) is connected to the lower platform (11) via the U-rotation joint A (151), the other end of the connecting rod D (155) is connected to one end of the connecting rod C (153) via the R-rotation joint C (152), and the other end of the connecting rod C (153) is connected to the upper platform (13) via the U-rotation joint B (154).

[0015] Furthermore, the flexible cable driving mechanism (3) comprises a plurality of groups of winding shafts (35) rotatably mounted on the base plate, each group of winding shafts (35) is driven by a winding motor (33) to rotate, each group of winding shafts (35) is wound with a flexible cable, and the flexible cables on each group of winding shafts (35) are output to the actuator module (1).

[0016] Furthermore, when the actuator module (1) includes only one set of low-degree-of-freedom parallel mechanisms, the lower platform (11) in the low-degree-of-freedom parallel mechanisms is provided with threading holes at positions for the flexible cables to pass through, and porcelain eyes are installed in the threading holes. After the flexible cables pass through the porcelain eyes, they are connected to the upper platform (13).

[0017] When the actuator module (1) comprises a plurality of groups of parallel mechanisms with a small degree of freedom, except for the upper platform of the last parallel mechanism with a small degree of freedom, the remaining upper and lower platforms are provided with through holes at positions for flexible cables to pass through, and ceramic eyes are installed in the through holes respectively. After the flexible cables pass through the ceramic eyes of the remaining upper and lower platforms except for the upper platform of the last parallel mechanism with a small degree of freedom, they are fixedly connected to the upper platform of the last parallel mechanism with a small degree of freedom.

[0018] Furthermore, chamfers are formed on both axial ends of the central through hole of the porcelain eye.

[0019] The present invention designs a hybrid robot with a low degree of freedom and a cable rod for spraying operations. On the basis of the traditional rigid link mechanism, a flexible cable and a rigid link are introduced to form a hybrid structure. The system stability is improved by the support of the rod, so that it has a large working space while having low weight and inertia, reducing the control difficulty, and making it fully utilized in a small space. It has two rotational degrees of freedom and one translational degree of freedom, and the movement is completely decoupled. During movement, the shape of the robot will not change significantly, the space utilization rate is high, it is not easy to be damaged during work, and a high rigidity is maintained. Therefore, the performance of the robot during spraying operations will be better than that of traditional flexible cable parallel robots.

[0020] The present invention not only retains the high rigidity and high precision characteristics of the parallel platform, making it more stable when crossing narrow terrain, but also retains the characteristics of the flexible cable drive, such as large load ratio, large working space and simple structure. The low-freedom parallel mechanism of the present invention adopts multiple links and multiple joints to connect the upper and lower platforms. The use of multiple links for connection can increase the movement space of the upper platform and achieve movement in a large angle range, so that the robot has higher flexibility during the spraying operation. While maintaining high rigidity, the flexible cable drive is used, and the motors can be arranged on the outside of the parallel platform and arranged in a centralized manner to increase the load ratio and make the force on the parallel platform more reasonable, thereby achieving accurate control of the end effector and effectively controlling the telescopic tension.

[0021] The present invention increases the working space of the robot through a parallel platform and controls the position and posture of the end effector in real time, which not only increases the working space of the equipment but also improves the accuracy and efficiency of the operation. It adopts a cable-rod hybrid structure, which improves the dexterity of the equipment while adjusting the tension of the rope in real time, thereby controlling the end more accurately.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] 1. The present invention is mainly divided into a low-degree-of-freedom parallel mechanism and a flexible cable drive mechanism. By combining different numbers of low-degree-of-freedom parallel mechanisms, a chain-type flexible cable parallel drive operation is formed.

[0024] 2. The present invention adopts a hybrid structure of ropes and connecting rods, which is much smaller in volume than a pure rigid structure and maintains a high load ratio. At the same time, the use of rope drive effectively reduces the number of driving connecting rods, thereby reducing the singular configuration of the robot and increasing the working space at the end.

[0025] 3. The low-degree-of-freedom parallel mechanism of the present invention adopts a rigid-flexible coupling structure. Each parallel platform adopts a rotating joint and a ball joint at the middle joint instead of the traditional moving joint connection, which not only increases the rigidity of the system, but also improves the flexibility of the entire parallel platform. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic structural diagram of a cable-rod hybrid robot with few degrees of freedom for spraying operations according to an embodiment of the present invention.

[0027] Figure 2 Schematic diagram of an actuator module according to an embodiment of the present invention.

[0028] Figure 3 Schematic diagram of RSR branching according to an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of a URU branch according to an embodiment of the present invention.

[0030] Figure 5 This is a schematic diagram of the PP branch of an embodiment of the present invention.

[0031] Figure 6 Schematic diagram of the upper platform according to an embodiment of the present invention.

[0032] Figure 7 Schematic diagram of a platform according to an embodiment of the present invention.

[0033] Figure 8 Schematic diagram of the R rotation joint according to an embodiment of the present invention.

[0034] Fig. 9 Schematic diagram of the joint cylinder according to an embodiment of the present invention.

[0035] Fig.10 Schematic diagram of a porcelain eye module according to an embodiment of the present invention.

[0036] Fig.11 Schematic diagram of a platform base according to an embodiment of the present invention.

[0037] Fig.12 Schematic diagram of a winding device according to an embodiment of the present invention.

[0038] Fig.13 Schematic diagram of a multi-stage series low-degree-of-freedom cable-rod hybrid robot according to an embodiment of the present invention.

[0039] Fig.14 The figure is a schematic diagram of the working process of an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the solutions of the present invention, the following will describe the implementation methods of the present invention in detail in conjunction with the accompanying drawings and embodiments, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve corresponding technical effects can be fully understood and implemented accordingly. The embodiments of the present invention and the various features in the embodiments can be combined with each other without conflict, and the technical solutions formed are all within the protection scope of the present invention.

[0041] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0042] It should be noted that the terms "include" and "have" in the specification and claims of the present invention and the above drawings and any modifications thereof are intended to cover non-exclusive inclusions.

[0043] like Figure 1-Figure 13 As shown, this embodiment discloses a cable-rod hybrid robot with few degrees of freedom for spraying operation, including a bottom plate, on which a platform base 2 is provided, such as Fig.11 As shown, a through hole is provided in the middle of the platform base 2. An actuator module 1 is provided on the platform base 2, and a flexible cable driving mechanism 3 is also provided on the bottom plate.

[0044] like Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7As shown, in this embodiment, the actuator module 1 includes at least one group of low-degree-of-freedom parallel mechanisms. Each group of low-degree-of-freedom parallel mechanisms includes an upper platform 13, a lower platform 11, and a PP branch 14, an RSR branch 12, a first URU branch 15, and a second URU branch 16 connected between the upper and lower platforms. Among them, the PP branch 14 is located between the center positions of the upper and lower platforms, and the RSR branch 12, the first URU branch 15, and the second URU branch 16 are equally spaced and distributed around the PP branch 12.

[0045] When the actuator module 1 includes only one group of small-degree-of-freedom parallel mechanisms, the lower platform 11 in the small-degree-of-freedom parallel mechanism is fixed on the platform base 2. When the actuator module 1 includes multiple groups of small-degree-of-freedom parallel mechanisms, each group of small-degree-of-freedom parallel mechanisms is distributed in a straight line, and the lower platform of one group of small-degree-of-freedom parallel mechanisms in adjacent small-degree-of-freedom parallel mechanisms serves as the upper platform of another group of small-degree-of-freedom parallel mechanisms, and the lower platform of the first group of small-degree-of-freedom parallel mechanisms is fixed on the platform base 2.

[0046] The flexible cable driving mechanism 3 outputs multiple groups of flexible cables to the actuator module 1. When the actuator module 1 includes only one group of parallel mechanisms with fewer degrees of freedom, each group of flexible cables passes through the lower platform 11 of the parallel mechanism with fewer degrees of freedom and is then fixedly connected to the upper platform 13. When the actuator module 1 includes multiple groups of parallel mechanisms with fewer degrees of freedom, each group of flexible cables passes through the remaining upper and lower platforms except the upper platform of the last parallel mechanism with fewer degrees of freedom and is then fixedly connected to the upper platform of the last parallel mechanism with fewer degrees of freedom.

[0047] Specifically, Figure 3 As shown, in each group of parallel mechanisms with few degrees of freedom, the RSR branch 12 includes an R revolute joint A121, an S ball joint C122, a connecting rod A123, an R revolute joint B124, and a connecting rod B125. One end of the connecting rod B125 is connected to the top surface of the lower platform 11 through the R revolute joint A121, and the other end of the connecting rod B125 is connected to one end of the connecting rod A123 through the S ball joint C122, and the other end of the connecting rod A123 is connected to the bottom surface of the upper platform 13 through the R revolute joint B124. In the RSR branch 12, the R revolute joint A121 and the R revolute joint B124 each have one degree of rotational freedom in a plane, and the S ball joint C122 has three degrees of rotational freedom in space, which is more flexible. The S ball joint C122 is used to connect the connecting rod A123 and the connecting rod B125. The S ball joint C122 has three degrees of freedom. Together with the one degree of freedom of the R revolute joint A121 and the R revolute joint B124, the RSR branch 12 has five rotational degrees of freedom.

[0048] like Figure 8As shown, the R rotation joint A121 and the R rotation joint B124 have the same structure, and are both composed of a joint base A1211, a joint bolt 1212, a joint base B1213, and a joint cylinder 1214. The joint base A1211 and the joint base B1213 are both provided with a plurality of threaded holes for connecting the connecting rod or the platform respectively. The joint cylinder 1214 is respectively connected to the joint base A1211 and the joint base B1213 through bearings, and the two ends of the joint cylinder 1214 are fixed by the joint bolt 1212, thereby realizing the movement of one degree of freedom in each plane of the R rotation joint A121 and the R rotation joint B124.

[0049] like Fig. 9 As shown, the joint cylinder 1214 has a symmetrical structure with a through hole in the middle. It is installed in the through holes of the joint base A1211 and the joint base B1213, and bearings are placed at both ends. Finally, bolts are passed through the through holes of the joint cylinder 1214, the joint base A1211 and the joint base B1213, and nuts are used to fix them at the other end, thereby realizing movement with one degree of rotational freedom.

[0050] like Figure 4 As shown, in each group of low-degree-of-freedom parallel mechanisms, the first URU branch 15 and the second URU branch 16 have the same structure, both including a U-rotation joint A151, an R-rotation joint C152, a connecting rod C153, a U-rotation joint B154, and a connecting rod D155. One end of the connecting rod D155 is connected to the top surface of the lower platform 11 through the U-rotation joint A151, and the other end of the connecting rod D155 is connected to one end of the connecting rod C153 through the R-rotation joint C152, and the other end of the connecting rod C153 is connected to the bottom surface of the upper platform 13 through the U-rotation joint B154. In the first URU branch 15 and the second URU branch 16, the U rotation joint A151 and the U rotation joint B154 each have two rotational degrees of freedom in an X-axis and a Y-axis in a plane, the R rotation joint C152 has one rotational degree of freedom in a plane, the U rotation joint A151 and the U rotation joint B154 can both complete movement with two degrees of freedom in the plane, the R rotation joint C152 is used to connect the connecting rod C153 and the connecting rod D155, so the first URU branch 15 and the second URU branch 16 each have five rotational degrees of freedom.

[0051] like Figure 5As shown, in each group of parallel mechanisms with few degrees of freedom, the PP branch 14 includes an S ball joint A141, a sleeve 142, a light rod 143, an S ball joint B144, and a spring 145. One axial end of the sleeve 142 is a barrel opening, and the other axial end is a closed end. The light rod 143 is partially slidably installed in the sleeve 142 to form a sliding pair. One end of the light rod 143 passes through the barrel opening of the sleeve 142, and the end of the light rod 143 located outside the barrel opening of the sleeve 142 is connected to the center position of the bottom surface of the upper platform 13 through the S ball joint B144, and the closed end of the sleeve 142 is connected to the center position of the top surface of the lower platform 11 through the S ball joint A141. The spring 145 is looped around the portion of the light rod 143 outside the mouth of the sleeve 142, one end of the spring 145 passes through the mouth of the sleeve 142 and is fixed inside the sleeve 142, and the other end of the spring 145 is fixed on the ring platform of the light rod 143 outside the mouth of the sleeve 142, so that the light rod 143 can move under the action of the spring deformation force. In the PP branch 14, the S ball joint A141 and the S ball joint B144 both have three degrees of rotational freedom in space, which is more flexible. The S ball joint B144 is used to connect the light rod 143 and the upper platform 13, and the S ball joint A141 is used to connect the sleeve 142 and the lower platform 11. Since the S ball joint B144 and the S ball joint A141 both have three degrees of freedom, the moving pair formed by the light rod 143 and the sleeve 142 has one degree of freedom, so the PP branch 14 has seven degrees of rotational freedom.

[0052] like Figure 6 As shown, in each group of parallel mechanisms with few degrees of freedom, the upper platform 13 is a disc, and positioning blocks A131, B132, and C133 are arranged at non-central positions on the bottom surface of the upper platform 13. Positioning blocks A131, B132, and C133 are circumferentially distributed at equal intervals around the central axis of the disc. Positioning blocks A131, B132, and C133 are respectively used to fix the U rotating joint B154 of the first URU branch 15, the R rotating joint B124 of the RSR branch 12, and the U rotating joint B1 of the second URU branch 16. A threaded hole is arranged at the central position of the bottom surface of the upper platform 13 to fix the S ball joint B144 of the PP branch 14. The three degrees of freedom of the S ball joint B144 are realized by threaded connection.

[0053] like Figure 7As shown, in each group of parallel mechanisms with few degrees of freedom, the lower platform 11 is a disc, and positioning blocks D111, E112, and F113 are provided at non-central positions on the top surface of the lower platform 11. Positioning blocks D111, E112, and F113 are used to fix the U rotating joint A151 of the first URU branch 15, the R rotating joint A121 of the RSR branch 12, and the U rotating joint A of the second URU branch 15, respectively. A threaded hole is provided at the central position of the bottom surface of the lower platform 11 to fix the S ball joint A141 of the PP branch 14, and the three degrees of freedom of the S ball joint A141 are realized by threaded connection.

[0054] In this embodiment, when the actuator module 1 has only one group of parallel mechanisms with few degrees of freedom, a plurality of threading holes are provided in the lower platform 11, and the threading holes are evenly distributed at equal intervals around the central axis of the lower platform 11, and each threading hole is used for each group of flexible cables output by the flexible cable driving mechanism 3 to pass through one by one.

[0055] When the actuator module 1 includes multiple groups of low-degree-of-freedom parallel mechanisms, except for the upper platform of the last low-degree-of-freedom parallel mechanism, the remaining upper and lower platforms are provided with multiple threading holes, and each threading hole is evenly distributed at equal intervals around the central axis of the corresponding platform, and each threading hole is used for each group of flexible cables output by the flexible cable driving mechanism 3 to pass through one by one.

[0056] In this embodiment, a ceramic eyelet module 17 is installed in each threading hole. Fig.10 As shown, the porcelain eye module 17 includes a porcelain eye end cover 171 and a porcelain eye base 174. The porcelain eye end cover 171 is installed on the porcelain eye base 174, and the porcelain eye end cover 171 is fixedly connected to the porcelain eye base 174 by a porcelain eye bolt 172. The porcelain eye end cover 171 and the porcelain eye base 174 have a coaxial central through hole, and the porcelain eye 173 is composed of the coaxial central through hole of the porcelain eye end cover 171 and the porcelain eye base 174. The porcelain eye 173 in the porcelain eye module 17 is for the flexible cable to pass through. In addition, the axial end openings of the porcelain eye 173 are respectively formed with outward-turned chamfers, which can reduce friction when the flexible cable passes through, thereby reducing the deviation of the structure itself.

[0057] like Fig.12As shown, in this embodiment, the flexible cable driving mechanism 3 includes multiple groups of winding devices, each group of winding devices includes a winding base 31, a winding reducer 32, a winding motor 33, a winding end cover 34, a winding shaft 35, a winding pulley 36, and a winding belt 37. There are two groups of winding end covers 34, both of which are fixed on the bottom plate. The winding shaft 35 is rotatably installed between the two groups of winding end covers 34, and can rotate 360 ​​degrees by itself to achieve a large angle of rotation. The flexible cable is wound on the winding shaft 35. The winding base 31 is fixed on the bottom plate, the winding motor 33 and the winding reducer 32 are fixed on the winding base 31, and the output shaft of the winding motor 33 is coaxially fixedly connected with the input shaft of the winding reducer 32. There are two winding pulleys 36, one of which is coaxially fixed to the output shaft of the winding reducer 32, and the other winding pulley 36 is coaxially fixed to one axial end of the winding shaft 35. The winding belt 37 is used to drive and connect the two winding pulleys 36. The winding pulley 36, the winding belt 37 are connected to the winding shaft 35, and finally the winding motor 33 drives the winding shaft 35 to rotate synchronously. In each group of winding devices, the flexible rope on the winding shaft 35 is output to the actuator module 1 respectively.

[0058] like Fig.14 As shown, the working process of the cable-rod hybrid robot with few degrees of freedom for spraying operation of the present invention is as follows:

[0059] (1) System initialization: first determine the position parameters of the workpiece, place the workpiece in a fixed position, adjust the parameters of the upper platform 13, the lower platform 11, the first URU1 branch 15, the second URU branch 16, the RSR branch 12, the PP branch 14, and the winding device 3, and input them into the control system host computer;

[0060] (2) The host computer determines the position of the main area of ​​the workspace according to the position parameters of the workpiece, the servo motor in the winding device 3 is started, and the rope is adjusted according to the position shape of the mechanism to balance the tension, and each module is in a stable position;

[0061] (3) During the movement of the upper platform 13, the tension sensor, the angle sensor, etc. collect data and output it to the host computer, so as to control the balancing mechanism to adjust with the movement of the end, adapt to the stiffness of the spring 143, so as to meet the stability and accuracy of the whole mechanism;

[0062] (4) The winding device controls the upper platform with a total of 3 degrees of freedom through 4 ropes. The ropes pass through the winding device 3, through the porcelain eye of the lower platform, and are connected to the upper platform. They cooperate with the URU branches, RSR branches and PP branches to enable the upper platform to reach the predetermined position.

[0063] (5) After ensuring that the workpiece is completely covered, the operation is completed and the system is initialized.

[0064] The above-mentioned actuator module, the RSR branch, the URU branch, the PP branch, the upper platform, the lower platform, the porcelain eye, the platform base, the winding device, the driving rope and the motor are only the preferred embodiments of the present invention. The winding device avoids interference from the rope, thereby improving the working space, flexibility and efficiency of the equipment as a whole. The present invention is a low-degree-of-freedom cable-rod hybrid robot for spraying operations, which can better perform real-time control of the end.

[0065] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. The examples described in the present invention are merely descriptions of the preferred embodiments of the present invention, and do not limit the concept and scope of the present invention. The various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction, and such combinations should also be regarded as the contents disclosed in the present disclosure as long as they do not violate the concept of the present invention. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0066] The present invention is not limited to the specific details of the above-mentioned embodiments. Within the scope of the technical concept of the present invention and without departing from the design concept of the present invention, various modifications and improvements made to the technical solution of the present invention by technical personnel in this field should fall within the protection scope of the present invention. The technical contents for which protection is sought in the present invention have been fully recorded in the claims.

Claims

1. A cable-rod hybrid robot with few degrees of freedom for spraying operations, characterized in that: It comprises a bottom plate, a platform base (2) is provided on the bottom plate, an actuator module (1) is provided on the platform base (2), and a flexible cable driving mechanism (3) is also provided on the bottom plate; The actuator module (1) comprises at least one group of low-degree-of-freedom parallel mechanisms, wherein the low-degree-of-freedom parallel mechanisms comprise an upper platform (13), a lower platform (11), and a PP branch (14), an RSR branch (12), a first URU branch (15), and a second URU branch (16) connected between the upper and lower platforms, wherein the PP branch (14) is located between the center positions of the upper and lower platforms, and the RSR branch (12), the first URU branch (15), and the second URU branch (16) are distributed around the PP branch (12); When the actuator module (1) includes only one set of parallel mechanisms with a small degree of freedom, the lower platform (11) in the parallel mechanism with a small degree of freedom is fixed to the platform base (2); When the actuator module (1) includes a plurality of groups of small-degree-of-freedom parallel mechanisms, the groups of small-degree-of-freedom parallel mechanisms are distributed in a straight line, and the lower platform of one group of small-degree-of-freedom parallel mechanisms among adjacent small-degree-of-freedom parallel mechanisms serves as the upper platform of another group of small-degree-of-freedom parallel mechanisms, and the lower platform of the first small-degree-of-freedom parallel mechanism is fixed on the platform base (2); The flexible cable driving mechanism (3) outputs a plurality of flexible cables to the actuator module (1); when the actuator module (1) includes only one group of parallel mechanisms with fewer degrees of freedom, each group of flexible cables passes through the lower platform (11) of the parallel mechanism with fewer degrees of freedom and is then fixedly connected to the upper platform (13); when the actuator module (1) includes multiple groups of parallel mechanisms with fewer degrees of freedom, each group of flexible cables passes through the remaining upper and lower platforms except the upper platform of the last parallel mechanism with fewer degrees of freedom and is then fixedly connected to the upper platform of the last parallel mechanism with fewer degrees of freedom.

2. A cable-rod hybrid robot with few degrees of freedom for spraying operations according to claim 1, characterized in that: In the low-freedom parallel mechanism, the PP branch (14) comprises an S ball joint A (141), a sleeve (142), a light rod (143), an S ball joint B (144), and a spring (145); one axial end of the sleeve (142) is a barrel opening, and the other axial end is a closed end; the light rod (143) is partially slidably installed in the sleeve (142) to form a sliding pair; one end of the light rod (143) passes through the barrel opening of the sleeve (142), and the light rod (143) is located at the barrel of the sleeve (142). The end outside the opening is connected to the upper platform (13) through the S ball joint B (144), and the closed end of the sleeve (142) is connected to the lower platform (11) through the S ball joint A (141); the spring (145) is sleeved on the portion of the light rod (143) located outside the opening of the sleeve (142), one end of the spring (145) passes through the opening of the sleeve (142) and is fixed in the sleeve (142), and the other end of the spring (145) is fixed to the portion of the light rod (143) located outside the opening of the sleeve (142).

3. The cable-rod hybrid robot with few degrees of freedom for spraying operation according to claim 1, characterized in that: In the low-degree-of-freedom parallel mechanism, the RSR branch (12) includes an R rotating joint A (121), an S ball joint C (122), a connecting rod A (123), an R rotating joint B (124), and a connecting rod B (125); one end of the connecting rod B (125) is connected to the lower platform (11) through the R rotating joint A (121), the other end of the connecting rod B (125) is connected to one end of the connecting rod A (123) through the S ball joint C (122), and the other end of the connecting rod A (123) is connected to the upper platform (13) through the R rotating joint B (124).

4. The cable-rod hybrid robot with few degrees of freedom for spraying operation according to claim 1, characterized in that: In the low-degree-of-freedom parallel mechanism, the first URU branch (15) and the second URU branch (16) have the same structure, both comprising a U-rotational joint A (151), an R-rotational joint C (152), a connecting rod C (153), a U-rotational joint B (154), and a connecting rod D (155); one end of the connecting rod D (155) is connected to the lower platform (11) via the U-rotational joint A (151), the other end of the connecting rod D (155) is connected to one end of the connecting rod C (153) via the R-rotational joint C (152), and the other end of the connecting rod C (153) is connected to the upper platform (13) via the U-rotational joint B (154).

5. The cable-rod hybrid robot with few degrees of freedom for spraying operation according to claim 1, characterized in that: The flexible cable driving mechanism (3) comprises a plurality of groups of winding shafts (35) rotatably mounted on a base plate, each group of winding shafts (35) being driven by a winding motor (33) to rotate, each group of winding shafts (35) being wound with flexible cables, and the flexible cables on each group of winding shafts (35) being output to the actuator module (1).

6. The cable-rod hybrid robot with few degrees of freedom for spraying operation according to claim 1, characterized in that: When the actuator module (1) includes only one set of low-degree-of-freedom parallel mechanisms, the lower platform (11) in the low-degree-of-freedom parallel mechanisms is provided with threading holes at positions for flexible cables to pass through, and ceramic eyes are installed in the threading holes. After the flexible cables pass through the ceramic eyes, they are connected to the upper platform (13). When the actuator module (1) comprises a plurality of groups of parallel mechanisms with a small degree of freedom, except for the upper platform of the last parallel mechanism with a small degree of freedom, the remaining upper and lower platforms are provided with through holes at positions for flexible cables to pass through, and ceramic eyes are installed in the through holes respectively. After the flexible cables pass through the ceramic eyes of the remaining upper and lower platforms except for the upper platform of the last parallel mechanism with a small degree of freedom, they are fixedly connected to the upper platform of the last parallel mechanism with a small degree of freedom.

7. The cable-rod hybrid robot with few degrees of freedom for spraying operation according to claim 6, characterized in that: The central through hole of the porcelain eye is chamfered at both axial ends.

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