Valve installation industrial robot and control method thereof

Abstract

The present application belongs to the technical field of industrial robots, and particularly relates to a valve installation industrial robot and a control method thereof. The valve installation industrial robot comprises a fixed platform, a position adjusting mechanism installed on the fixed platform, a clamping jaw mechanism fixedly installed at an output end of the extension mechanism, and a screwing mechanism installed on the fixed platform for driving the clamping jaw mechanism to rotate. The clamping jaw mechanism comprises a servo motor, a screw rod, a guide assembly, and at least three groups of clamping jaw assemblies. An upper connecting platform, a movable platform, and a lower connecting platform are sequentially and parallelly arranged below the servo motor. The clamping jaw linkage, the movable platform, and the lower connecting platform constitute a movable pair to realize the clamping / loosing action of the clamping jaw, i.e. to ensure the clamping installation of parts with different sizes and the rigidity of the clamping jaw. Only one power source is needed to convert the up-down movement of the movable platform into the clamping / loosing action of the clamping jaw, and the clamping is stable, easy to be automatically controlled, and easy to be maintained.

Description

Technical Field

[0001] This invention belongs to the field of industrial robot technology, specifically relating to a valve installation industrial robot and its control method. Background Technology

[0002] With the significant improvement in living standards, the comprehensive enhancement of national strength, and the rapid development of science and technology, all sectors of China have entered a new era of automated production. The concept of automated factories is increasingly becoming a mainstream trend. To maintain a leading position in the rapidly changing society and market competition, enterprises must continuously improve their innovation and competitiveness, making the replacement of manual operations inevitable. As people pursue a higher quality of life and a greater sense of well-being, the demand for products continues to expand. However, relying solely on manual production is not only costly and inefficient but also fails to meet current market demands, thus spurring the inevitable development of automated tightening devices. To gain a competitive edge in the fierce market competition, many manufacturers are focusing on the research and development of new models and striving to standardize multi-specification co-production lines. However, in the process of adopting new technologies, processes, and equipment, production sites are gradually facing problems such as aging equipment, insufficient workstations, difficulties in identifying diverse product specifications, and increased occupational injuries for employees. Addressing these challenges, ensuring smooth production and reducing labor costs has become a common problem that assembly workshops in the manufacturing industry need to solve.

[0003] Existing screwing mechanisms for parts are mostly specially designed for a specific type of part. For example, nut screwing mechanisms often use rotating sleeves. Each screwing mechanism can only be used for screwing one type of nut and cannot be used for screwing nuts of various sizes. Screwing mechanisms with self-adaptive functions lack rigidity, and parts are prone to falling off during the screwing process, causing safety accidents. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of existing technologies, such as the single size of the screwing parts, insufficient rigidity during the screwing process, and easy detachment of parts, and to provide a valve installation industrial robot with wider applicability and greater rigidity and its control method.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] As a first aspect, a valve installation industrial robot includes a fixed platform, a position adjustment mechanism mounted on the fixed platform, a gripper mechanism fixedly mounted to the output end of the extension mechanism, and a screwing mechanism mounted on the fixed platform for driving the gripper mechanism to rotate.

[0007] The gripper mechanism includes:

[0008] A servo motor is mounted on the output end of the extension mechanism via a transition shaft;

[0009] The lead screw is coaxially arranged with the output shaft of the servo motor;

[0010] An upper connecting platform, a movable platform, and a lower connecting platform are sequentially and parallelly arranged below the servo motor; the upper connecting platform is fixedly connected to the fixed end of the servo motor, the movable platform is threadedly connected to the lead screw, and the lead screw is rotatably connected to the upper connecting platform and the lower connecting platform through bearings;

[0011] A guide component is disposed between the upper connecting platform and the lower connecting platform, and is slidably disposed with respect to the active platform;

[0012] At least three sets of gripper assemblies are arranged in a circumferential array on the lower connecting platform, and all are rotatably connected to the lower connecting platform and the movable platform; wherein,

[0013] The distance between any two adjacent gripper assemblies and the mounting point of the movable platform is greater than the distance between them and the mounting point of the lower connecting platform; when the movable platform is close to the upper connecting platform, the gripper assembly is in an open state; when the movable platform is close to the lower connecting platform, the gripper assembly is in a gripping state.

[0014] Furthermore, the gripper assembly includes:

[0015] The first rotating component and the second rotating component are respectively rotatably configured to rotate with the active platform and the lower connecting platform;

[0016] A gripper connecting rod, one end of which is fixedly mounted with a gripper for gripping the workpiece to be installed, and the other end passes through the second rotating member and the first rotating member from bottom to top in sequence. The gripper connecting rod is fixedly disposed with the second rotating member, and the gripper connecting rod is slidably disposed with the first rotating member through a guide wheel set.

[0017] When the movable platform moves closer to the lower connecting platform, the gripper linkage slides within the first rotating component, causing the second rotating component to rotate relative to the lower connecting platform, and the multiple grippers converge to clamp the workpiece to be installed.

[0018] When the active platform moves closer to the upper connecting platform, the gripper linkage slides within the first rotating member, causing the second rotating member to rotate relative to the lower connecting platform, and the multiple grippers disperse from each other.

[0019] Furthermore, the position adjustment mechanism includes a hydraulic control circuit and a hydraulic cylinder connected to the hydraulic control circuit.

[0020] The cylinder body of the hydraulic cylinder is fixedly installed on the fixed platform, and the telescopic rod of the hydraulic cylinder extends out of the fixed platform and is connected to the gripper mechanism through the screwing mechanism; the gripper mechanism moves vertically following the telescopic rod of the hydraulic cylinder.

[0021] Furthermore, the hydraulic control circuit includes an oil tank, a variable pump connected to the oil tank, a solenoid directional valve, and a pressure gauge installed on the oil line between the variable pump and the solenoid directional valve; the solenoid directional valve is connected to the hydraulic cylinder circuit.

[0022] When the solenoid directional valve is in the left position, the hydraulic cylinder extends its telescopic rod; when the solenoid directional valve is in the middle position, the extension of the hydraulic cylinder stops; when the solenoid directional valve is in the right position, the hydraulic cylinder retracts its telescopic rod.

[0023] Furthermore, the screwing mechanism includes a brushless DC motor mounted on the fixed platform, a drive gear coaxially arranged with the output shaft of the brushless DC motor, a ring gear externally meshing with the drive gear, and a mounting flange fixedly mounted on the ring gear by bolts; the fixed end of the servo motor is mounted on the mounting flange, and the ring gear is sleeved on the outside of the transition shaft and coaxially arranged with the transition shaft.

[0024] Furthermore, the guiding component includes:

[0025] At least three guide rods are fixedly installed between the upper connecting platform and the lower connecting platform;

[0026] At least two guide blocks are fixedly mounted on the movable platform; wherein,

[0027] The guide block passes through the outside of the guide rod and slides along the guide rod.

[0028] Furthermore, it also includes a control unit, which includes a DC power supply, a hydraulic start / stop switch, a normally closed hydraulic cylinder extension / retraction switch, a normally open hydraulic cylinder extension / retraction switch, a servo motor start / stop switch, a normally open servo motor forward / reverse rotation switch, a normally closed servo motor forward / reverse rotation switch, a motor driver, and a DC brushless motor forward / reverse rotation switch.

[0029] The hydraulic start / stop switch is electrically connected to the positive terminal of the DC power supply. The hydraulic start / stop switch is connected in series with the normally open hydraulic cylinder extension / retraction switch and the A1 / A2 interface of the solenoid directional valve, and then returns to the negative terminal of the DC power supply. The normally closed hydraulic cylinder extension / retraction switch and the A3 / A4 interface of the solenoid directional valve are connected in series, and then connected in parallel with the series circuit of the normally open hydraulic cylinder extension / retraction switch and the A1 / A2 interface of the solenoid directional valve.

[0030] The servo motor start / stop switch is electrically connected to the positive terminal of the DC power supply. The servo motor start / stop switch is connected in series with the servo motor forward / reverse normally open switch and the A1 / A2 interface of the motor driver, and then returned to the negative terminal of the DC power supply. The servo motor forward / reverse normally closed switch is connected in series with the A3 / A4 interface of the motor driver, and then connected in series with the servo motor forward / reverse normally open switch and the A1 / A2 interface of the motor driver.

[0031] The forward / reverse switch of the brushless DC motor is connected in series with the brushless DC motor and then electrically connected to the DC power supply.

[0032] As a second aspect, a control method for a valve installation industrial robot is characterized by comprising the following steps:

[0033] S1. Control the gripper mechanism to extend to the base position, that is, control the movement of the hydraulic cylinder through the hydraulic control oil circuit, and drive the gripper mechanism to move in the vertical direction through the transition shaft until it moves to the desired position;

[0034] S2. The gripper mechanism positions and clamps the part to be installed;

[0035] S3. Tightening and installing the part to be installed, that is, based on the positioning and clamping of the part to be installed in step S3, start the DC brushless motor to drive the extension rod of the hydraulic cylinder, the upper connecting platform, the servo motor, the lower connecting platform and the gripper mechanism to rotate synchronously, and tighten and install the part to be installed.

[0036] S4. The gripper mechanism disengages from the part to be installed, and the telescopic rod of the hydraulic cylinder returns to its original position.

[0037] Specifically, the clamping mechanism in step S2 for positioning and clamping the part to be installed includes the following steps:

[0038] S201. When the servo motor start / stop switch is closed, the A3 and A4 interfaces of the motor driver are energized, the servo motor reverses, and the multiple gripper links are in the farthest relative state.

[0039] S202. Close the normally open switch for forward and reverse rotation of the servo motor. The A1 and A2 interfaces of the motor driver are energized, and the motor changes from reverse rotation to forward rotation. The movable platform moves down and tightens the gripper until the gripper clamps the part to be installed.

[0040] When the gripper clamps the part to be installed, the hydraulic start / stop switch is disconnected and the solenoid directional valve is de-energized and returns to the neutral position.

[0041] Specifically, the screwing installation of the component to be installed in step S3 above includes the following steps:

[0042] S301. The rotation angle of the brushless DC motor is calculated and adjusted using sliding mode control and a tracking differentiator to set the corresponding turning angle of the part to be installed.

[0043] S302. Close the forward and reverse switch of the brushless DC motor, and the brushless DC motor A1 and A2 ports are energized and rotate;

[0044] S303. When tightening the part to be installed, disconnect the forward and reverse switch of the DC brushless motor. The DC brushless motor A1 and A2 ports are de-energized and stop rotating, thus completing the screwing and installation of the part to be installed.

[0045] The beneficial effects of the valve installation industrial robot and its control method of the present invention are:

[0046] The gripper mechanism of the present invention is provided with an upper connecting platform and a lower connecting platform with a fixed relative distance, and a movable platform that can move between the upper connecting platform and the lower connecting platform. The clamping / unclamping action of the gripper is realized by the movable pair formed by the gripper connecting rod, the lower connecting platform and the movable platform. This ensures the clamping and installation of parts of different sizes, and also ensures the rigidity of the gripper clamping. Moreover, only one power source is needed to convert the up and down movement of the movable platform into the clamping / unclamping action of the gripper. The gripping is stable, easy to automate and easy to maintain. Attached Figure Description

[0047] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0048] Figure 1 This is a diagram showing the valve installation robot and the valve's turning position in an embodiment of the present invention.

[0049] Figure 2 This is a partial structural schematic diagram of the valve installation robot according to an embodiment of the present invention.

[0050] Figure 3 This is an installation diagram of the screwing mechanism and the gripper mechanism in an embodiment of the present invention.

[0051] Figure 4 This is a first-view perspective perspective view of the gripper mechanism in an embodiment of the present invention.

[0052] Figure 5 This is a second-view perspective perspective view of the gripper mechanism in an embodiment of the present invention.

[0053] Figure 6 This is a flowchart of the control method according to an embodiment of the present invention.

[0054] Figure 7 This is a schematic diagram of the control circuit according to an embodiment of the present invention.

[0055] Figure 8 This is a flowchart of the control method according to an embodiment of the present invention.

[0056] Figure 9 This is a control block diagram of a brushless DC motor according to an embodiment of the present invention.

[0057] In the diagram: 1. Fixed platform; 2. Position adjustment mechanism; 21. Hydraulic control circuit; 212. Variable pump; 213. Solenoid directional valve; 214. Pressure gauge; 22. Hydraulic cylinder; 3. Gripper mechanism; 31. Servo motor; 32. Lead screw; 33. Upper connecting platform; 34. Movable platform; 35. Lower connecting platform; 36. Guide assembly; 361. Guide rod; 362. Guide block; 37. Gripper assembly; 371. First rotating component; 372. Second rotating component; 373. Gripper connecting rod; 374. Guide wheel assembly; 375. 38. Gripper, 4. Transition shaft, 4. Twisting mechanism, 41. DC brushless motor, 42. Drive gear, 43. Ring gear, 5. Part to be installed, 6. Control unit, 61. DC power supply, 62. Hydraulic start / stop switch, 63. Hydraulic cylinder extension / retraction normally closed switch, 64. Hydraulic cylinder extension / retraction normally open switch, 65. Servo motor start / stop switch, 66. Servo motor forward / reverse normally open switch, 67. Servo motor forward / reverse normally closed switch, 68. Motor driver, 69. DC brushless motor forward / reverse switch, 610. Emergency stop switch, 7. Valve. Detailed Implementation

[0058] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0059] like Figures 1-5The present invention illustrates a specific embodiment of a valve installation industrial robot, including a fixed platform 1, a position adjustment mechanism 2 mounted on the fixed platform 1, a gripper mechanism 3 fixedly mounted to the output end of the extension mechanism, and a screwing mechanism 4 mounted on the fixed platform 1 for driving the gripper mechanism 3 to rotate. The gripper mechanism 3 includes: a servo motor 31, a lead screw 32, a guide assembly 36, at least three sets of gripper assemblies 37, and an upper connecting platform 33, a movable platform 34, and a lower connecting platform 35 arranged in parallel below the servo motor 31. The servo motor 31 is mounted on the output end of the extension mechanism via a transition shaft 38. The lead screw 32 is coaxially aligned with the output shaft of the servo motor 31. The upper connecting platform 33 is fixedly connected to the fixed end of the servo motor 31. The movable platform 34 is threadedly connected to the lead screw 32. The lead screw 32 is rotatably connected to the upper connecting platform 33 and the lower connecting platform 35 via bearings. The guide assembly 36 is positioned between the upper connecting platform 33 and the lower connecting platform 35 and slidably aligned with the movable platform 34. At least three sets of gripper assemblies 37 are arranged in a circumferential array on the lower connecting platform 35 and are rotatably connected to both the lower connecting platform 35 and the movable platform 34. The distance between any two adjacent gripper assemblies 37 and the mounting point on the movable platform 34 must be greater than the distance between them and the mounting point on the lower connecting platform 35. When the movable platform 34 approaches the upper connecting platform 33, the gripper assemblies 37 are in an open state; when the movable platform 34 approaches the lower connecting platform 35, the gripper assemblies 37 are in a gripping state.

[0060] The gripper mechanism 3 of the present invention is provided with an upper connecting platform 33 and a lower connecting platform 35 with a fixed relative distance, and a movable platform 34 that can move between the upper connecting platform 33 and the lower connecting platform 35. The clamping / releasing action of the gripper 375 is realized by the movable pair formed by the gripper connecting rod 373, the lower connecting platform 35, and the movable platform 34. This ensures the clamping and installation of parts of different sizes, and also ensures the clamping rigidity of the gripper 375. Moreover, only one power source is needed to convert the up and down movement of the movable platform 34 into the clamping / releasing action of the gripper 375. The gripping is stable, easy to automate, and easy to maintain.

[0061] The gripper assembly 37 in this embodiment includes a first rotating member 371 and a second rotating member 372, which are rotatably configured to rotate with the movable platform 34 and the lower connecting platform 35, respectively. It also includes a gripper connecting rod 373 and grippers 375 corresponding to the gripper connecting rod 373. One end of the gripper connecting rod 373 is fixedly mounted with a gripper 375 for gripping the workpiece to be installed. The other end passes through the second rotating member 372 and the first rotating member 371 sequentially from bottom to top. The gripper connecting rod 373 is fixedly configured with the second rotating member 372, and the gripper connecting rod 373 is slidably configured with the first rotating member 371 via a guide wheel assembly 374.

[0062] During use, when the movable platform 34 moves closer to the lower connecting platform 35, the gripper linkage 373 slides within the first rotating member 371, causing the second rotating member 372 to rotate relative to the lower connecting platform 35, and the multiple grippers 375 converge to clamp the workpiece to be installed. When the movable platform 34 moves closer to the upper connecting platform 33, the gripper linkage 373 slides within the first rotating member 371, causing the second rotating member 372 to rotate relative to the lower connecting platform 35, and the multiple grippers 375 disperse.

[0063] In this embodiment, the movable platform 34 in the gripper assembly 37 forms a screw 32-nut rotation pair with the lead screw 32. The lead screw 32 rotates under the drive of the servo motor 31, which drives the movable platform 34 to move in the direction of the lead screw 32 axis, that is, to move up and down in this embodiment. The guide assembly 36 includes at least three guide rods 361 and at least two guide blocks 362. The at least three guide rods 361 are fixedly disposed between the upper connecting platform 33 and the lower connecting platform 35, and the at least two guide blocks 362 are fixedly disposed on the movable platform 34. The guide blocks 362 pass through the outside of the guide rods 361 and slide along the guide rods 361.

[0064] In a preferred embodiment, the gripper assembly 37 consists of four sets. Four guide rods 361 are arranged between the upper connecting platform 33 and the lower connecting platform 35, and two guide blocks 362 are slidably arranged corresponding to two of the guide rods 361. In this embodiment, the movable platform 34 and the lead screw 32 form a sliding pair, and the four guide rods 361 and the two guide blocks 362 limit and guide the movement direction of the movable platform 34 to ensure the stability of the movement of the movable platform 34.

[0065] like Figure 4 and Figure 5 As shown, the clamping and releasing actions of the gripper mechanism 3 in this embodiment are as follows:

[0066] The clamping action of the gripper mechanism 3: The motor driver 68 sends a signal to the servo motor 31, and the servo motor 31 rotates by a corresponding angle. The output shaft of the servo motor 31 drives the lead screw to rotate through the coupling, thereby causing the movable platform 34 to move linearly relative to the lead screw, achieving the purpose of converting rotational motion into linear motion. The movable platform 34 is connected to the gripper connecting rod 373. The downward linear motion of the movable platform 34 relative to the lead screw drives the four gripper connecting rods 373 to perform a relative tightening motion, and finally drives the gripper 375 to clamp the part 5 to be installed.

[0067] The releasing action of the gripper mechanism 3 is achieved by reversing the servo motor 31 based on the clamping action described above, causing the movable platform 34 to move upward in a linear motion relative to the lead screw 32. This will not be elaborated further here. This embodiment utilizes a retractable gripper mechanism to automatically clamp the part 5 to be installed. This design expands the applicability of the automatic tightening equipment and improves the assembly success rate, thereby effectively shortening the maintenance and adjustment downtime of the production line.

[0068] Reference Figure 2 In this embodiment, the position adjustment mechanism 2 includes a hydraulic control circuit 21 and a hydraulic cylinder 22 connected to the hydraulic control circuit 21. The cylinder body of the hydraulic cylinder 22 is fixedly mounted to the fixed platform 1. The telescopic rod of the hydraulic cylinder 22 extends out of the fixed platform 1 and is connected to the gripper mechanism 3 via a screwing mechanism 4. The gripper mechanism 3 moves vertically following the telescopic rod of the hydraulic cylinder 22. Further, the hydraulic control circuit 21 in this embodiment includes an oil tank, a variable pump 212 connected to the oil tank, an electromagnetic directional valve 213, and a pressure gauge 214 installed on the oil line between the variable pump 212 and the electromagnetic directional valve 213. The electromagnetic directional valve 213 is connected to the hydraulic cylinder 22. Specifically, in use, when the electromagnetic directional valve 213 is in the left position, the hydraulic cylinder 22 extends its telescopic rod; when the electromagnetic directional valve 213 is in the middle position, the extension of the hydraulic cylinder 22 stops; when the electromagnetic directional valve 213 is in the right position, the hydraulic cylinder 22 retracts its telescopic rod.

[0069] The position adjustment mechanism 2 is used to initially adjust the position of the gripper mechanism 3, laying the groundwork for the subsequent clamping and tightening of the component 5 to be installed. The position adjustment process of the valve installation industrial robot is as follows:

[0070] Hydraulic oil flows from variable pump 212 into pressure regulating valve, then through pressure gauge 214 into solenoid directional valve 213, and finally into port A of hydraulic cylinder 22. The telescopic lever of hydraulic cylinder 22 moves downwards under the pressure of the hydraulic oil, thereby driving transition shaft 38 downwards and extending gripper mechanism 3, laying the foundation for subsequent work.

[0071] like Figure 2 and Figure 3As shown, the tightening mechanism 4 in this embodiment includes a DC brushless motor 41 mounted on a fixed platform 1, a drive gear 42 coaxially arranged with the output shaft of the DC brushless motor 41, a ring gear 43 externally meshing with the drive gear 42, and a mounting flange fixedly mounted on the ring gear 43 by bolts. The fixed end of the servo motor 31 is mounted on the mounting flange, and the ring gear 43 is sleeved around the outside of the transition shaft 38 and coaxially arranged with the transition shaft 38. It should be further noted that a coupling is provided on the gear shaft of the drive gear 42. In use, after the DC brushless motor 41 is powered on and started, it drives the coupling to rotate, and the coupling drives the drive gear 42 to rotate. Through gear transmission, the ring gear 43 is driven to rotate. The ring gear 43 drives the transition shaft 38 to rotate, and through the transition shaft 38, it drives the gripper mechanism 3 to rotate, thereby rotating and tightening the clamped part 5 to be installed.

[0072] The tightening mechanism 4 in this embodiment is simple in structure and easy to operate. The entire tightening process requires no manual intervention, significantly improving operational efficiency and reducing accuracy errors. It can automatically complete the workpiece tightening work, shortening the operator's waiting time and demonstrating the advantages of high automation and high efficiency.

[0073] like Figure 7 As shown, the valve installation robot in this embodiment also includes a control unit 6. The control unit 6 includes a DC power supply 61, a hydraulic start / stop switch 62, a normally closed hydraulic cylinder extension / retraction switch 63, a normally open hydraulic cylinder extension / retraction switch 64, a servo motor start / stop switch 65, a normally open servo motor forward / reverse rotation switch 66, a normally closed servo motor forward / reverse rotation switch 67, a motor driver 68, and a DC brushless motor forward / reverse rotation switch 69.

[0074] In one implementation, the connection method of each part in the control unit 6 in this embodiment is as follows: the hydraulic start-stop switch 62 is electrically connected to the positive terminal of the DC power supply 61, and the hydraulic start-stop switch 62 is connected in series with the normally open hydraulic cylinder extension switch 64 and the A1 / A2 interface of the electromagnetic reversing valve 213 in sequence, and then returned to the negative terminal of the DC power supply 61; the normally closed hydraulic cylinder extension switch 63 and the A3 / A4 interface of the electromagnetic reversing valve 213 are connected in series, and then connected in parallel with the series circuit of the normally open hydraulic cylinder extension switch 64 and the A1 / A2 interface of the electromagnetic reversing valve 213.

[0075] The servo motor start / stop switch 65 is electrically connected to the positive terminal of the DC power supply 61. The servo motor start / stop switch 65 is then connected in series with the normally open forward / reverse switch 66 and the A1 / A2 interface of the motor driver 68, before returning to the negative terminal of the DC power supply 61. The normally closed forward / reverse switch 67 is connected in series with the A3 / A4 interface of the motor driver 68, and then connected in series with the normally open forward / reverse switch 66 and the A1 / A2 interface of the motor driver 68. The DC brushless motor forward / reverse switch 69 is connected in series with the DC brushless motor 41 and then electrically connected to the DC power supply 61.

[0076] In this embodiment, the DC power supply 61 uses a 24V power supply. Specifically, the upper port of the hydraulic start / stop switch 62 is connected to the 24V electrical interface of the DC power supply 61 via line P101, and the lower port of the hydraulic start / stop switch 62 is connected to the contact of the normally open hydraulic cylinder extension / retraction switch 64 via line P102. The lower port of the normally open hydraulic cylinder extension / retraction switch 64 is connected to port A1 of the solenoid directional valve 213 via line P103, and port A2 of the solenoid directional valve 213 is connected to the 0V port of the DC power supply 61 via line N101. The upper port of the normally open hydraulic cylinder extension / retraction switch 64 is connected to the contact of the normally closed hydraulic cylinder extension / retraction switch 63 via line P104. The normally closed hydraulic cylinder extension / retraction switch 63 is connected to port A3 of the solenoid directional valve 213. Port A4 of the solenoid directional valve 213 is connected to the 0V port of the DC power supply 61.

[0077] The upper port of hydraulic start / stop switch 62 is connected to the 24V electrical interface of DC power supply 61 via line P101. The lower port of hydraulic start / stop switch 62 is connected to the first contact of normally open hydraulic cylinder extension / retraction switch 64 via line P102. The lower port of the first contact of normally open hydraulic cylinder extension / retraction switch 64 is connected to port A1 of solenoid directional valve 213 via line P103. Port A2 of solenoid directional valve 213 is connected to the 0V port of DC power supply 61 via line N101. The upper port of the second contact of normally open hydraulic cylinder extension / retraction switch 64 is connected to the first contact of normally closed hydraulic cylinder extension / retraction switch 63 via line P104. The second contact of normally closed hydraulic cylinder extension / retraction switch 63 is connected to port A3 of solenoid directional valve 213. Port A4 of solenoid directional valve 213 is connected to the 0V port of DC power supply 61.

[0078] The upper port of the servo motor start / stop switch 65 is connected to the 24V electrical interface of the DC power supply 61 via line P106. The lower port of the servo motor start / stop switch 65 is connected to the interface of the servo motor forward / reverse normally open switch 66 via line P107. The lower port of the servo motor forward / reverse normally open switch 66 is connected to the A1 port of the motor driver 68 via line P108. The A2 port of the motor driver 68 is connected to the 0V port of the DC power supply 61 via line N103. The upper port of the contact of the servo motor forward / reverse normally open switch 66 is connected to the upper contact of the servo motor forward / reverse normally closed switch 67 via line P109. The lower port of the contact of the servo motor forward / reverse normally closed switch 67 is connected to the A3 port of the motor driver 68. The A4 port of the motor driver 68 is connected to the 0V port of the DC power supply 61 via line N104.

[0079] The upper port of the DC brushless motor forward / reverse switch 69 is connected to the 24V electrical interface of the DC power supply 61 via line P111. The lower port of the DC brushless motor forward / reverse switch 69 is connected to the DC brushless motor 41A1 port via line P112, and the DC brushless motor 41A2 port is connected to the DC power supply 61 0V port via line N105.

[0080] To ensure safe operation, the control unit 6 in this embodiment is also equipped with an emergency stop switch (610), which is connected to the 0V port of the DC power supply 61. In case of an emergency, the operator can immediately activate the emergency stop switch (610) to quickly stop the equipment. This design provides important safety protection for the equipment and the operator, effectively preventing potential damage to the machinery and workpieces, thereby significantly enhancing overall safety and reducing potential safety risks.

[0081] The valve installation industrial robot of this invention achieves automatic clamping of the gripper 375 and automatic tightening of screws through fully automated operation, without human intervention, thus completely automating the installation of valves 7. This innovation not only solves the problem of traditional equipment relying on manual operation, but also improves work efficiency and accuracy, while reducing labor intensity and operation time.

[0082] like Figure 6 and Figure 8 As shown, the control method for the valve installation industrial robot described above includes the following steps:

[0083] S1. Control the gripper mechanism 3 to extend to the base position, that is, control the hydraulic cylinder 22 to move through the hydraulic control oil circuit 21, and drive the gripper mechanism 3 to move in the vertical direction through the transition shaft 38 until it moves to the desired position;

[0084] S2. The gripper mechanism 3 positions and clamps the part 5 to be installed;

[0085] S3. Tightening and installing the component 5 to be installed: In step S3, based on the positioning and clamping of the component 5 to be installed, the DC brushless motor 41 is started, which drives the extension rod of the hydraulic cylinder 22, the upper connecting platform 33, the servo motor 31, the lower connecting platform 35 and the gripper mechanism 3 to rotate synchronously, and the component 5 to be installed is tightened and installed.

[0086] S4. The gripper mechanism 3 disengages from the part to be installed 5, and the extension rod of the hydraulic cylinder 22 returns to its original position.

[0087] In step S1, the specific process of controlling the gripper mechanism 3 to extend to the base position is as follows:

[0088] First, close the hydraulic start / stop switch 62. This energizes ports A3 and A4 of the solenoid directional valve 213, placing it in the right position. This ensures the hydraulic cylinder 22 is fully retracted, allowing for better subsequent operations. Next, close the hydraulic cylinder extension / retraction normally open switch 64, energizing ports A1 and A2 of the solenoid valve 213. This places the valve in the left position, extending the extension rod of the hydraulic cylinder 22. When the gripper 375 reaches the appropriate position, the hydraulic start / stop switch 62 can be disconnected, de-energizing the solenoid valve 213 and returning it to the neutral position. Finally, the hydraulic cylinder 22 stops moving. This lays the foundation for subsequent operations.

[0089] In this embodiment, step S2, in which the gripper mechanism 3 positions and clamps the part 5 to be installed, specifically includes the following steps:

[0090] S201. When the servo motor start / stop switch 65 is closed, the A3 and A4 interfaces of the motor driver 68 are energized, the servo motor 31 reverses, and the multiple gripper links 373 are in the farthest relative state.

[0091] S202. Close the normally open forward / reverse switch 66 of the servo motor. The A1 and A2 interfaces of the motor driver 68 are energized, and the servo motor 31 changes from reverse to forward rotation. The movable platform 34 moves down and tightens the gripper bar until the gripper 375 clamps the part to be installed 5, and the servo motor 31 stops. When the gripper 375 clamps the part to be installed 5, the hydraulic start / stop switch 62 is opened, and the solenoid directional valve 213 is de-energized and returns to the neutral position.

[0092] The screwing installation of component 5 in step S3 specifically includes the following steps:

[0093] S301. The rotation angle of the DC brushless motor 41 is adjusted by using sliding mode control and a tracking differentiator to calculate and adjust the corresponding screwing angle of the component 5 to be installed.

[0094] S302. When the DC brushless motor forward / reverse switch 69 is closed, the DC brushless motor 41A1 and A2 ports are energized and rotate;

[0095] S303. When tightening the part to be installed 5, disconnect the DC brushless motor forward and reverse switch 69. The DC brushless motor 41A1 and A2 ports will stop rotating due to power failure, thus completing the screwing and installation of the part to be installed 5.

[0096] See Figure 9 This embodiment shows the control block diagram of the brushless DC motor 41. The brushless DC motor 41 is controlled by a tracking differentiator (TD), a sliding mode control module (SMC), and an extended state observer (ESO). SMC has unique switching characteristics, enabling discontinuous changes in the control structure. Since the sliding mode reaching law can be designed as needed and is unaffected by changes in system parameters and external disturbances, sliding mode control has advantages such as strong robustness, fast response speed, insensitivity to parameter changes, and simple structure. However, the control signal may produce jitter. To achieve stability of the hydraulic system and reduce the required selection parameters while accelerating error convergence, a sliding mode state error feedback control rate (SMSEF) is used to improve the system bandwidth. Furthermore, the sliding mode active disturbance rejection control method is used to make the electro-hydraulic servo loading system reach the desired stable reference model, thereby improving system stability. Here, ui is the target signal, θ is the output angle of the brushless DC motor 41, and uc is the feedback signal.

[0097] The tracking differentiator (TD) is responsible for generating the transient response and derivative of the velocity signal. The tracking differentiator can quickly and accurately track the input signal with minimal overshoot, generating a high-quality differential signal. Using the tracking differentiator, these undesirable dynamic responses can be significantly reduced, resulting in more stable and accurate control. The extended state observer (ESO) plays a central role in the active disturbance rejection controller (ADRC), its importance manifesting in several aspects: first, it affects the dynamic and steady-state performance of the system; second, it can monitor and compensate for internal and external disturbances to the system; and third, it can monitor the system state, historical inputs, and differential differences of various orders in the signal, providing data support for error feedback adjustment. Through these functions, the extended state observer effectively solves the problem of model dependence in the control process and can determine the appropriate compensation amount by evaluating disturbances, thereby achieving active disturbance rejection of unmodeled internal dynamics and unknown external disturbances. Furthermore, the application of the nonlinear state error feedback control law (SMSEF) provides a nonlinear combination method for handling errors, further improving the accuracy and adaptability of the control system.

[0098] The specific implementation process is as follows:

[0099] First, the target voltage signal ua is input to TD. After processing the signal, TD can quickly and accurately track the input signal ue with almost no overshoot. This significantly reduces these unfavorable dynamic responses, resulting in a more stable and accurate control effect. The signal then passes through SMSEF, which outputs a voltage signal ud to the motor driver 68. The motor driver 68 outputs a pulse signal a to the brushless DC motor 41, which then drives the gripper 375 to perform corresponding actions. The rotation angle θ is measured by the encoder of the brushless DC motor 41 and converted into a voltage signal, which is sent to ESO. ESO processes the signal and finally outputs a feedback signal uc, which is subtracted from the signal ue output by TD and output as ub to SMSEF, thus forming a closed-loop control. Therefore, the rotation angle of the brushless DC motor 41 can be adjusted by setting the target voltage signal ua, achieving precise feedback control of the brushless DC motor 41.

[0100] It should be understood that the specific embodiments described above are for illustrative purposes only and are not intended to limit the scope of the invention. Obvious variations or modifications derived from the spirit of the invention are still within the protection scope of the invention.

Claims

1. A valve installation industrial robot, characterized in that, It includes a fixed platform (1), a position adjustment mechanism (2) installed on the fixed platform (1), a gripper mechanism (3) fixedly installed with the output end of the extension mechanism, and a screwing mechanism (4) installed on the fixed platform (1) for driving the gripper mechanism (3) to rotate. The gripper mechanism (3) includes: A servo motor (31) is mounted on the output end of the extension mechanism via a transition shaft (38); The lead screw (32) is coaxially arranged with the output shaft of the servo motor (31); An upper connecting platform (33), a movable platform (34), and a lower connecting platform (35) are arranged in parallel below the servo motor (31); the upper connecting platform (33) is fixedly connected to the fixed end of the servo motor (31), the movable platform (34) is threadedly connected to the lead screw (32), and the lead screw (32) is rotatably connected to the upper connecting platform (33) and the lower connecting platform (35) through bearings; A guide component (36) is disposed between the upper connecting platform (33) and the lower connecting platform (35), and is slidably disposed with respect to the active platform (34); At least three sets of gripper assemblies (37) are arranged in a circumferential array on the lower connecting platform (35), and are all rotatably connected to the lower connecting platform (35) and the movable platform (34); wherein, The distance between any two adjacent gripper assemblies (37) and the mounting point of the movable platform (34) is greater than the distance between them and the mounting point of the lower connecting platform (35); when the movable platform (34) is close to the upper connecting platform (33), the gripper assembly (37) is in an open state; when the movable platform (34) is close to the lower connecting platform (35), the gripper assembly (37) is in a gripping state. The gripper assembly (37) includes: The first rotating component (371) and the second rotating component (372) are respectively rotatably configured with respect to the movable platform (34) and the lower connecting platform (35); A gripper link (373) is provided with a gripper (375) for gripping the workpiece to be installed at one end, and the other end passes through the second rotating member (372) and the first rotating member (371) from bottom to top. The gripper link (373) is fixedly installed with the second rotating member (372), and the gripper link (373) is slidably installed with the first rotating member (371) through a guide wheel assembly (374). When the active platform (34) moves closer to the lower connecting platform (35), the gripper connecting rod (373) slides in the first rotating member (371), causing the second rotating member (372) to rotate relative to the lower connecting platform (35), and the multiple grippers (375) gather together to clamp the workpiece to be installed. When the active platform (34) moves closer to the upper connecting platform (33), the gripper link (373) slides within the first rotating member (371), causing the second rotating member (372) to rotate relative to the lower connecting platform (35), and the multiple grippers (375) disperse from each other.

2. The valve installation industrial robot according to claim 1, characterized in that: The position adjustment mechanism (2) includes a hydraulic control circuit (21) and a hydraulic cylinder (22) connected to the hydraulic control circuit (21). The cylinder body of the hydraulic cylinder (22) is fixedly installed on the fixed platform (1). The telescopic rod of the hydraulic cylinder (22) extends out of the fixed platform (1) and is connected to the gripper mechanism (3) through the screwing mechanism (4). The gripper mechanism (3) moves vertically following the telescopic rod of the hydraulic cylinder (22).

3. The valve installation industrial robot according to claim 2, characterized in that: The hydraulic control circuit (21) includes an oil tank, a variable pump (212) connected to the oil tank, an electromagnetic directional valve (213), and a pressure gauge (214) installed on the oil line between the variable pump (212) and the electromagnetic directional valve (213); the electromagnetic directional valve (213) is connected to the hydraulic cylinder (22). When the solenoid directional valve (213) is in the left position, the hydraulic cylinder (22) extends the telescopic rod; when the solenoid directional valve (213) is in the middle position, the extension action of the hydraulic cylinder (22) stops; when the solenoid directional valve (213) is in the right position, the hydraulic cylinder (22) retracts the telescopic rod.

4. The valve installation industrial robot according to claim 1, characterized in that: The screwing mechanism (4) includes a DC brushless motor (41) mounted on the fixed platform (1), a drive gear (42) coaxially arranged with the output shaft of the DC brushless motor (41), a ring gear (43) externally meshing with the drive gear (42), and a mounting flange fixedly mounted on the ring gear (43) by bolts; the fixed end of the servo motor (31) is mounted on the mounting flange, and the ring gear (43) is sleeved on the outside of the transition shaft (38) and coaxially arranged with the transition shaft (38).

5. The valve installation industrial robot according to claim 1, characterized in that: The guide component (36) includes: At least three guide rods (361) are fixedly disposed between the upper connecting platform (33) and the lower connecting platform (35); At least two guide blocks (362) are fixedly mounted on the active platform (34); wherein, The guide block (362) passes through the outside of the guide rod (361) and is slidably disposed along the guide rod (361).

6. The valve installation industrial robot according to claim 5, characterized in that: It also includes a control unit (6), which includes a DC power supply (61), a hydraulic start / stop switch (62), a normally closed hydraulic cylinder extension / retraction switch (63), a normally open hydraulic cylinder extension / retraction switch (64), a servo motor start / stop switch (65), a normally open servo motor forward / reverse rotation switch (66), a normally closed servo motor forward / reverse rotation switch (67), a motor driver (68), and a DC brushless motor forward / reverse rotation switch (69). The hydraulic start / stop switch (62) is electrically connected to the positive terminal of the DC power supply (61). The hydraulic start / stop switch (62) is connected in series with the normally open hydraulic cylinder extension switch (64) and the electromagnetic reversing valve (213) via the A1 / A2 interface, and then returns to the negative terminal of the DC power supply (61). The normally closed hydraulic cylinder extension switch (63) and the electromagnetic reversing valve (213) are connected in series via the A3 / A4 interface, and then connected in parallel with the normally open hydraulic cylinder extension switch (64) and the electromagnetic reversing valve (213) via the A1 / A2 interface in the series circuit. The servo motor start / stop switch (65) is electrically connected to the positive terminal of the DC power supply (61). The servo motor start / stop switch (65) is connected in series with the servo motor forward / reverse normally open switch (66) and the A1 / A2 interface of the motor driver (68) and then back to the negative terminal of the DC power supply (61). The servo motor forward / reverse normally closed switch (67) is connected in series with the A3 / A4 interface of the motor driver (68) and then connected in series with the servo motor forward / reverse normally open switch (66) and the A1 / A2 interface of the motor driver (68). The DC brushless motor forward / reverse switch (69) is connected in series with the DC brushless motor (41) and then electrically connected to the DC power supply (61).

7. The control method for a valve installation industrial robot according to claim 6, characterized in that, Includes the following steps: S1. Control the gripper mechanism (3) to extend to the base position, that is, control the hydraulic cylinder (22) to move through the hydraulic control oil circuit (21), and drive the gripper mechanism (3) to move in the vertical direction through the transition shaft (38) until it moves to the required position; S2. The gripper mechanism (3) positions and clamps the part to be installed (5); S3. Tightening installation of the part to be installed (5): In step S3, based on the positioning and clamping of the part to be installed (5), start the DC brushless motor (41) to drive the extension rod of the hydraulic cylinder (22), the upper connecting platform (33), the servo motor (31), the lower connecting platform (35) and the gripper mechanism (3) to rotate synchronously and tighten the part to be installed (5). S4. The gripper mechanism (3) disengages from the part to be installed (5), and the telescopic rod of the hydraulic cylinder (22) returns to its original position.

8. The control method for a valve installation industrial robot according to claim 7, characterized in that, The clamping mechanism (3) in step S2, which positions and clamps the part to be installed (5), specifically includes the following steps: S201. Close the servo motor start / stop switch (65), the A3 and A4 interfaces of the motor driver (68) are powered, the servo motor (31) reverses, and the multiple gripper links (373) are in the farthest relative state. S202. Close the normally open switch (66) for forward and reverse rotation of the servo motor. The A1 and A2 interfaces of the motor driver (68) are powered on. The servo motor (31) changes from reverse rotation to forward rotation. The movable platform (34) moves down to tighten the claw bar until the gripper (375) clamps the part to be installed (5). The servo motor (31) stops. When the gripper (375) clamps the part to be installed (5), the hydraulic start / stop switch (62) is disconnected and the electromagnetic reversing valve (213) is de-energized and returns to the neutral position.

9. The control method for a valve installation industrial robot according to claim 8, characterized in that, The screwing installation of the component to be installed (5) in step S3 specifically includes the following steps: S301. Set the turning angle corresponding to the part to be installed (5) by using sliding mode control and tracking differential to calculate and adjust the rotation angle of the DC brushless motor (41). S302. Close the forward and reverse switch (69) of the brushless DC motor, and the brushless DC motor (41) A1 and A2 ports are energized and rotate; S303. When tightening the part to be installed (5), disconnect the DC brushless motor forward and reverse switch (69), the A1 and A2 ports of the DC brushless motor (41) are de-energized and stop rotating, and the screwing installation action of the part to be installed (5) is completed.

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