A low-degree-of-freedom cable-rod hybrid robot for spraying operations

Abstract

The present invention discloses a low-degree-of-freedom cable-rod hybrid robot for spraying operations, comprising a bottom plate, a platform base, and a flexible cable drive mechanism provided on the bottom plate, an actuator module provided on the platform base, the actuator module comprising at least one group of low-degree-of-freedom parallel mechanisms, and the flexible cable drive mechanism outputting multiple groups of flexible cables to the actuator module. The present invention adopts a cable-rod parallel form as a whole to increase the working space and load capacity of the present invention, so that it can adapt to a variety of irregular workpieces, and the winding device can avoid the interference of the rope itself and the interference between the rope and the workpiece. The present invention retains the characteristics of high rigidity and high precision of the parallel platform, and also retains the characteristics of large load ratio, large working space and simple structure of the rope drive. It can increase the load ratio to make the upper platform move more flexibly, so that it can cross narrow gaps and be fully utilized in narrow spaces, thereby achieving accurate control of the end effector and effectively controlling the telescopic tension.

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 a key development in artificial intelligence technology, robots play a crucial role in both industry and everyday life. Rigid parallel robots, in particular, have recently garnered significant attention due to their advantages, including zero cumulative error, excellent dynamic response, and high load-bearing capacity. However, their inherent complexity leads to interference between different branches, which limits the mechanism's range of motion. Furthermore, their poor spatial mobility makes them more susceptible to singular configurations, ultimately leading to sudden changes in the mechanism's degrees of freedom and forces, causing abnormal movement and even damage. Furthermore, the substantial mass of the rigid rods themselves prevents the maximum speed of the mechanism's end during motion from meeting the requirements of high-speed motion. Rigid robots also present safety issues regarding interaction with operators and the working environment.

[0003] With the development of robotics, soft robots can perform complex transformations and obstacle avoidance maneuvers, adapting to their environments through self-transformation. In security and military reconnaissance, small, stealthy robots are needed to perform surveillance tasks. High-altitude operations require lightweight, highly maneuverable, and safe robots to assist or replace humans. In rescue and search operations, facing uncertain environments, small and flexible robots are needed to rescue lives within ruins. For example, Chinese invention patent application number CN202211022783.4 describes a plant-like soft robotic arm that decouples stiffness from steering. This robotic arm enables real-time active steering and decouples stiffness from steering, improving end-load capacity. For example, Chinese invention patent application number CN202110676165.0 describes a pneumatically driven snake-like soft robot. This snake-like soft robot has a simple structure and is easy to manufacture, capable of spatial bending motion with two degrees of freedom: yaw and pitch. However, due to the material and structural characteristics of soft robots, they have low stability and repeatability when performing precise tasks, and their own stiffness is greatly reduced.

[0004] Therefore, the present invention proposes a parallel mechanism driven by a hybrid of ropes and rigid rods, which can utilize gravity, buoyancy, or elastic force to maintain all rope tension. Gravity and buoyancy are generally 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. This hybrid cable-rod structure overcomes the high mass, high inertia, and rod interference issues of purely rigid rod mechanisms, while also improving the stiffness issues of purely flexible rope mechanisms. Simultaneously, by adopting a configuration with fewer degrees of freedom, its kinematic and dynamic models are simplified, reducing control difficulty and coupling between different branches. This can meet the needs of most industrial operations while reducing mechanism complexity and production costs. Summary of the Invention

[0005] The present invention provides a cable-rod hybrid robot with low 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 comprises a base plate, a platform base (2) is provided on the base plate, an actuator module (1) is provided on the platform base (2), and a flexible cable drive mechanism (3) is also provided on the base plate;

[0008] The actuator module (1) includes at least one group of low-degree-of-freedom parallel mechanisms, wherein the low-degree-of-freedom parallel mechanisms include 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 low-degree-of-freedom parallel mechanisms, the lower platform (11) in the low-degree-of-freedom parallel mechanisms is fixed to the platform base (2);

[0010] When the actuator module (1) includes multiple 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 group of small-degree-of-freedom parallel mechanisms is fixed on the platform base (2);

[0011] The flexible cable drive 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.

[0012] Furthermore, in the low-degree-of-freedom parallel mechanism, the PP branch (14) includes 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 rotation joint A (121), an S ball joint C (122), a connecting rod A (123), an R rotation 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 rotation 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 rotation 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) through 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) through the R-rotation joint C (152), and the other end of the connecting rod C (153) is connected to the upper platform (13) through the U-rotation joint B (154).

[0015] Furthermore, the flexible cable drive mechanism (3) includes 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 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) includes multiple groups of parallel mechanisms with fewer degrees of freedom, except for the upper platform of the last parallel mechanism with fewer degrees of freedom, the remaining upper and lower platforms are provided with through holes at positions for flexible cables to pass through, and porcelain eyes are installed in the through holes. After the flexible cables pass through the porcelain eyes of the remaining upper and lower platforms except for the upper platform of the last parallel mechanism with fewer degrees of freedom, they are fixedly connected to the upper platform of the last parallel mechanism with fewer degrees 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 low-degree-of-freedom cable-rod hybrid robot for spraying operations. Based on the traditional rigid linkage mechanism, a flexible cable and rigid link are introduced to form a hybrid structure. The support of the rod improves the stability of the system, making it have a large workspace while having low weight and inertia, reducing the difficulty of control and enabling it to be fully utilized in confined spaces. It has two rotational degrees of freedom and one translational degree of freedom, and its motion is completely decoupled. During movement, the robot's shape does not change significantly, space utilization is high, it is not easily damaged during operation, and it maintains a high degree of rigidity. Therefore, the robot's performance in spraying operations will be superior to 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 large load ratio, large working space and simple structure of the flexible cable drive. The low-freedom parallel mechanism of the present invention uses 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 a large angle range of movement, so that the robot has higher flexibility during the spraying operation. While maintaining high rigidity, the flexible cable drive is used, and the motor 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 robot's working space through a parallel platform and controls the position 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. The cable-rod hybrid structure improves the dexterity of the equipment while adjusting the tension of the rope in real time, thereby achieving more accurate control of the end.

[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. This invention utilizes a hybrid cable and connecting rod structure, which significantly reduces its volume compared to purely rigid structures while maintaining a high load ratio. Furthermore, the use of cable drive effectively reduces the number of driving connecting rods, thereby minimizing the robot's singular configurations and increasing the end-of-line workspace.

[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 mobile 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 This is a schematic structural diagram of a cable-rod hybrid robot with low 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 branches in an embodiment of the present invention.

[0029] Figure 4 This is a schematic diagram of URU branches in an embodiment of the present invention.

[0030] Figure 5 Schematic diagram of PP branch in 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 the 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] Figure 9 Schematic diagram of the joint cylinder according to an embodiment of the present invention.

[0035] Figure 10 This is a schematic diagram of a porcelain eye module according to an embodiment of the present invention.

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

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

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

[0039] Figure 14 Schematic diagram of the working process of an embodiment of the present invention. DETAILED DESCRIPTION

[0040] To help those skilled in the art better understand the present invention, the following detailed description of the embodiments of the present invention is provided in conjunction with the accompanying drawings and examples. This will help those skilled in the art to fully understand and implement the present invention by applying technical means to solve technical problems and achieve corresponding technical effects. The embodiments of the present invention and the various features therein may be combined with each other as long as they do not conflict with each other, and the resulting technical solutions are all within the scope of protection of the present invention.

[0041] Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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, claims and drawings of the present invention and any variations thereof are intended to cover non-exclusive inclusions.

[0043] like Figures 1-13 As shown, this embodiment discloses a low-freedom cable-rod hybrid robot for spraying operations, including a bottom plate, a platform base 2 is provided on the bottom plate, as shown in FIG. Figure 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 drive 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 low-DOF parallel mechanism. Each low-DOF parallel mechanism 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. The PP branch 14 is located between the centers of the upper and lower platforms, while the RSR branch 12, the first URU branch 15, and the second URU branch 16 are equally spaced around the PP branch 12.

[0045] When the actuator module 1 includes only one low-degree-of-freedom parallel mechanism, the lower platform 11 of the low-degree-of-freedom parallel mechanism is fixed to the platform base 2. When the actuator module 1 includes multiple low-degree-of-freedom parallel mechanisms, the low-degree-of-freedom parallel mechanisms are arranged in a straight line, and the lower platform of one of the adjacent low-degree-of-freedom parallel mechanisms serves as the upper platform of the other low-degree-of-freedom parallel mechanism, with the lower platform of the first low-degree-of-freedom parallel mechanism fixed to the platform base 2.

[0046] The cable drive mechanism 3 outputs multiple sets of cables to the actuator module 1. When the actuator module 1 includes only one low-degree-of-freedom parallel mechanism, each set of cables passes through the lower platform 11 of the low-degree-of-freedom parallel mechanism before being fixedly connected to the upper platform 13. When the actuator module 1 includes multiple low-degree-of-freedom parallel mechanisms, each set of cables passes through the upper and lower platforms of all but the last low-degree-of-freedom parallel mechanism before being fixedly connected to the upper platform of the last low-degree-of-freedom parallel mechanism.

[0047] Specifically, such as Figure 3 As shown, in each low-degree-of-freedom parallel mechanism, the RSR branch 12 includes an R-revolving joint A121, an S-ball joint C122, a connecting rod A123, an R-revolving joint B124, and a connecting rod B125. One end of connecting rod B125 is connected to the top surface of the lower platform 11 via the R-revolving joint A121. The other end of connecting rod B125 is connected to one end of connecting rod A123 via the S-ball joint C122. The other end of connecting rod A123 is connected to the bottom surface of the upper platform 13 via the R-revolving joint B124. In the RSR branch 12, the R-revolving joints A121 and B124 each have one rotational degree of freedom within a plane, while the S-ball joint C122 has three rotational degrees of freedom within space, providing greater flexibility. The S ball joint C122 is used to connect the link A123 and the link B125. The S ball joint C122 has three degrees of freedom. Together with the one degree of freedom each 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, R revolute joint A121 and R revolute joint B124 have identical structures, each consisting of a joint base A1211, a joint bolt 1212, a joint base B1213, and a joint cylinder 1214. Both joint bases A1211 and B1213 have multiple threaded holes for connecting to connecting rods or platforms, respectively. Joint cylinder 1214 is connected to joint bases A1211 and B1213 via bearings, respectively. Joint cylinder 1214 is secured at both ends by joint bolts 1212, enabling one degree of freedom of motion in each plane for R revolute joint A121 and R revolute joint B124.

[0049] like Figure 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 achieving movement with one degree of rotational freedom.

[0050] like Figure 4 As shown, in each low-DOF parallel mechanism, the first URU branch 15 and the second URU branch 16 have identical structures, each comprising a U-rotary joint A151, an R-rotary joint C152, a connecting rod C153, a U-rotary joint B154, and a connecting rod D155. One end of connecting rod D155 is connected to the top surface of the lower platform 11 via the U-rotary joint A151. The other end of connecting rod D155 is connected to one end of connecting rod C153 via the R-rotary joint C152. The other end of connecting rod C153 is connected to the bottom surface of the upper platform 13 via the U-rotary 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 a plane, namely the X-axis and the Y-axis, and 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. Therefore, 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 low-degree-of-freedom parallel mechanism, the PP branch 14 includes an S-shaped ball joint A141, a sleeve 142, a polished rod 143, an S-shaped ball joint B144, and a spring 145. The sleeve 142 has a barrel opening at one axial end and a closed end at the other axial end. The polished rod 143 is partially slidably mounted within the sleeve 142 to form a sliding pair. One end of the polished rod 143 extends beyond the barrel opening of the sleeve 142. The end of the polished rod 143 located outside the barrel opening of the sleeve 142 is connected to the center of the bottom surface of the upper platform 13 via an S-shaped ball joint B144. The closed end of the sleeve 142 is connected to the center of the top surface of the lower platform 11 via an S-shaped ball joint A141. The spring 145 is looped around 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 inside the sleeve 142. The other end of the spring 145 is fixed to the ring platform of the light rod 143 located outside the opening of the sleeve 142. Under the action of the spring deformation force, the light rod 143 can move. In the PP branch 14, the S ball joint A141 and the S ball joint B144 both have three rotational degrees of 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 freedom of rotation.

[0052] like Figure 6 As shown, in each low-degree-of-freedom parallel mechanism, the upper platform 13 is a circular disk. Positioning blocks A131, B132, and C133 are located at non-central locations on the bottom surface of the upper platform 13. These blocks are equidistantly spaced around the central axis of the disk. These blocks A131, B132, and C133 respectively secure the U-shaped revolving joint B154 of the first URU branch 15, the R-shaped revolving joint B124 of the RSR branch 12, and the U-shaped revolving joint B1 of the second URU branch 16. A threaded hole is located at the center of the bottom surface of the upper platform 13 to secure the S-shaped ball joint B144 of the PP branch 14. This threaded connection provides three degrees of freedom for the S-shaped ball joint B144.

[0053] like Figure 7As shown, in each low-degree-of-freedom parallel mechanism, the lower platform 11 is a circular disk. Positioning blocks D111, E112, and F113 are located non-centrally on the top surface of the lower platform 11. These blocks D111, E112, and F113 are used to secure the U-shaped revolute joint A151 of the first URU branch 15, the R-shaped revolute joint A121 of the RSR branch 12, and the U-shaped revolute joint A of the second URU branch 15, respectively. A threaded hole is located at the center of the bottom surface of the lower platform 11 to secure the S-shaped ball joint A141 of the PP branch 14. This threaded connection provides three degrees of freedom for the S-shaped ball joint A141.

[0054] In this embodiment, when the actuator module 1 has only one set of parallel mechanisms with few degrees of freedom, a plurality of threading holes are provided in the lower platform 11. The threading holes are evenly distributed at equal intervals around the central axis of the lower platform 11. The threading holes allow each set of flexible cables output by the flexible cable drive 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. 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 porcelain eye module 17 is also installed in each threading hole. Figure 10 As shown, the eyelet module 17 includes an eyelet end cap 171 and an eyelet base 174. The eyelet end cap 171 is mounted on the eyelet base 174 and is fixed to the eyelet base 174 via eyelet bolts 172. The eyelet end cap 171 and the eyelet base 174 each have a coaxial central through-hole. The coaxial central through-holes of the eyelet end cap 171 and the eyelet base 174 form an eyelet 173, which is a passage for the flexible cable. Furthermore, the axial ends of the eyelet 173 are formed with outward-turned chamfers to reduce friction when the flexible cable passes through, thereby minimizing structural deviation.

[0057] like Figure 12As shown, in this embodiment, the flexible cable drive mechanism 3 includes multiple winding devices, each of which comprises a winding base 31, a winding reducer 32, a winding motor 33, a winding end cap 34, a winding shaft 35, a winding pulley 36, and a winding belt 37. There are two sets of winding end caps 34, both fixed to the base plate. The winding shaft 35 is rotatably mounted between the two sets of winding end caps 34 and can rotate 360 ​​degrees, achieving a large rotation angle. The flexible cable is wound around the winding shaft 35. The winding base 31 is fixed to the base plate, and the winding motor 33 and winding reducer 32 are fixed to the winding base 31. The output shaft of the winding motor 33 is coaxially fixedly connected to 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 is coaxially fixed to one axial end of the winding shaft 35. A winding belt 37 is used to drive the two winding pulleys 36. The winding pulleys 36, winding belt 37, and winding shaft 35 are connected to achieve synchronous rotation of the winding shaft 35 driven by the winding motor 33. In each winding device, the flexible cable on the winding shaft 35 is output to the actuator module 1.

[0058] like Figure 14 As shown, the working process of the low-degree-of-freedom cable-rod hybrid robot for spraying operations 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, lower platform 11, first URU1 branch 15, second URU branch 16, RSR branch 12, PP branch 14, and 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 based on the position parameters of the workpiece, and the servo motor in the winding device 3 is started. The rope is adjusted according to the position 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, thereby controlling the balance mechanism to adjust with the end movement and adapt to the stiffness of the spring 143 to meet the stability and accuracy of the entire 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 each URU branch, RSR branch and PP branch 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 drive rope and the motor are only preferred embodiments of the present invention. The winding device avoids interference from the rope, and improves 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 with reference to 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 unless there is any contradiction. Such combinations should also be regarded as the contents disclosed in this 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 those skilled in the art should fall within the scope of protection of the present invention. The technical content for which protection is sought in the present invention has 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 drive mechanism (3) is also provided on the bottom plate; The actuator module (1) includes at least one group of low-degree-of-freedom parallel mechanisms, the low-degree-of-freedom parallel mechanisms including 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 (14); 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 fixed to the platform base (2); When the actuator module (1) includes multiple 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 group of small-degree-of-freedom parallel mechanisms is fixed on the platform base (2); The flexible cable drive 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 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. In the low-freedom parallel mechanism, the PP branch (14) includes 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 barrel of the sleeve (142). One 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).

2. A cable-and-rope hybrid robot with low degrees of freedom for spraying operations according to claim 1, characterized in that: In the low-degree-of-freedom parallel mechanism, the RSR branch (12) includes an R rotation joint A (121), an S ball joint C (122), a connecting rod A (123), an R rotation 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 rotation 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 rotation joint B (124).

3. The cable-rod hybrid robot with low degrees of freedom for spraying operations 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-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).

4. The cable-rod hybrid robot with low degree of freedom for spraying operations according to claim 1, characterized in that: The flexible cable drive 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 a flexible cable, and the flexible cables on each group of winding shafts (35) being output to the actuator module (1).

5. The cable-rod hybrid robot with low degree of freedom for spraying operations 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 mechanism is provided with threading holes at positions for flexible cables to pass through, and porcelain eyes are installed in the threading holes. The flexible cables are connected to the upper platform (13) after passing through the porcelain eyes. When the actuator module (1) includes 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 porcelain eyes are installed in the through holes. After the flexible cables pass through the porcelain 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.

6. The cable-rod hybrid robot with low degree of freedom for spraying operations according to claim 5, characterized in that: The central through hole of the porcelain eye is chamfered at both axial ends.

Images