Material taking and placing method of linear rotation actuator

Abstract

The invention relates to the technical field of actuator control, in particular to a material taking and placing method of a linear rotation actuator. The linear rotation actuator comprises a controller, a linear motor and a rotating motor, the linear motor is connected with the rotating motor, an air guide pipe penetrates through the rotating motor and then is connected with a suction nozzle, the air guide pipe is connected with a positive and negative pressure air source and is provided with an air pressure sensor and a micro air valve, and the linear rotation actuator is connected with an upper controller through a high-speed bus. According to the method, the materials can be quickly picked up and released by utilizing the linear rotation actuator, and compared with a traditional control strategy, the communication waiting time is saved, the action efficiency is improved to the maximum extent, the response speed is improved, and the system structure cost is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of actuator control, and in particular to a material picking and placing method of a linear rotary actuator. Background Art

[0002] Traditional linear-rotary actuators are responsible for approaching objects, but do not have the ability to pick and place materials. Figure 1 The figure shows the current application of linear rotary actuators in equipment, which are responsible for realizing two actions: vertical and rotation. The vertical action is used to approach the target material, and the rotation action is used to adjust the angle of the target material. After approaching the target, whether the material is successfully picked up currently requires the installation of additional host controllers and detection devices, which are dispatched and controlled by the host controller. Figure 1 The solution involves the upper controller, linear rotary actuator, barometer, PLC and air valve. The upper controller coordinates the action sequence of each party through communication or IO interaction. Due to the overall complexity, the material picking and releasing process control strategy takes a long time. With the advancement of technology, production efficiency is required to be further improved. Therefore, a linear rotary actuator with a more optimized control strategy is urgently needed to ultimately speed up the material picking and releasing rhythm. Summary of the invention

[0003] The problem to be solved by the present invention is to provide a linear rotary actuator with a more optimized control strategy, thereby ultimately speeding up the rhythm of taking and placing materials.

[0004] In view of the deficiencies of the prior art, the technical solution adopted by the present invention to solve the technical problems is: a material picking and placing method of a linear rotary actuator, the method involves a linear rotary actuator, the linear rotary actuator comprises a controller, a linear motor, and a rotary motor, the linear motor is connected to the rotary motor, the air guide pipe passes through the rotary motor and is connected to a suction nozzle, the air guide pipe is connected to a positive and negative pressure air source and is provided with an air pressure sensor and a micro air valve, the linear rotary actuator is connected to a host controller via a high-speed bus, the controller communicates with the linear motor, the rotary motor, the air pressure sensor and the micro air valve, and comprises the following steps:

[0005] Step 1: The upper controller issues a picking instruction;

[0006] Step 2: The controller receives the pick-up instruction and controls the linear rotary actuator to pick up the material;

[0007] Step 3: The upper controller issues a release command;

[0008] Step 4: The controller receives the release instruction and controls the linear rotary actuator to release the material.

[0009] Preferably, the specific process of the linear rotary actuator picking up the material in step 2 is as follows:

[0010] 1. The controller receives the pick-up instruction from the upper controller, and the controller controls the opening of the micro air valve to pass negative pressure;

[0011] 2. The controller controls the linear motor to softly land and approach the material;

[0012] 3. The controller determines whether the soft landing of the linear motor is completed. If the soft landing of the linear motor is not completed, the controller enters the timing waiting period until the soft landing of the linear motor is completed. If the timing waiting period exceeds the waiting threshold, the controller checks for faults.

[0013] 4. After the linear motor soft landing is completed, determine whether the air pressure value detected by the air pressure sensor is less than the preset value A; if not, enter the timing waiting stage; if the timing waiting stage exceeds the waiting threshold, check for faults;

[0014] 5. If the air pressure value detected by the air pressure sensor is less than the preset value A, the controller controls the linear motor to lift the material and end the picking.

[0015] Preferably, the process of releasing the material by the linear rotary actuator in step 4 is as follows:

[0016] 1. The controller receives the release command from the upper controller, and controls the linear motor to soft land;

[0017] 2. The controller determines whether the soft landing of the linear motor is completed. If the soft landing of the linear motor is completed, the controller controls the micro air valve to close the negative pressure. If the soft landing of the linear motor is not completed, the controller enters the timing waiting period until the soft landing of the linear motor is completed. If the timing waiting period exceeds the waiting threshold, the controller checks for faults.

[0018] 3. Determine whether the air pressure value detected by the air pressure sensor is greater than the preset value B; if not, enter the timing waiting state; if the timing waiting state exceeds the waiting threshold, troubleshoot the fault;

[0019] 4. If the air pressure value detected by the air pressure sensor is greater than the preset value B, the material is released and the controller controls the linear motor to retract.

[0020] Preferably, preset value A is smaller than preset value B.

[0021] The beneficial effects of the present invention are as follows: The method of the present invention enables the actuator to have the ability to automatically pick up and place materials, speeds up the rhythm of picking up and placing materials, maximizes the efficiency of the action, reduces the cost of the system structure, and makes the equipment easier to use. By enabling the linear rotary actuator to have the ability to pick up materials, the system design is simplified and the overall cost is reduced. The system design is simplified, the response speed is improved, and the system cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the use of an existing linear rotary actuator in the background technology;

[0023] Figure 2It is a schematic diagram of the structure of the linear rotary actuator of the present invention;

[0024] Figure 3 It is the application topology diagram of the linear rotary actuator of the present invention;

[0025] Figure 4 It is a flow chart of the material picking process involved in the present invention;

[0026] Figure 5 It is a traditional picking time series graph;

[0027] Figure 6 It is a picking timing diagram involved in the present invention;

[0028] Figure 7 It is a material release flow chart involved in the present invention;

[0029] Figure 8 Traditional material release timing diagram;

[0030] Fig. 9 It is a material release timing diagram involved in the present invention;

[0031] Explanation of the accompanying drawings: 1. controller; 2. linear motor; 3. rotary motor; 4. air pressure sensor; 5. micro air valve; 6. air guide tube; 7. suction nozzle; 8. linear motor stator; 9. connecting plate; 10. linear rotary actuator. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific uses.

[0033] Figure 1 This is a schematic diagram of the use of an existing linear rotary actuator in the background technology. Figure 1 The upper-middle controller is the master control unit, which needs to communicate with multiple devices such as linear rotary actuators, barometers, PLCs, etc. After comprehensively processing the data of each device, it finally controls the linear rotary actuator to complete the material pick-up and placement. The reciprocating interaction between the various devices will cause time consumption, limiting the further improvement of the production cycle. Therefore, in order to improve production efficiency, the present invention optimizes the control strategy for material picking and placement, and the specific contents are as follows.

[0034] Figure 2This is a schematic diagram of the main components of the linear rotary actuator 10 involved in the present invention. The linear rotary actuator 10 includes a controller 1. The controller 1 is connected to the linear motor 2, the rotary motor 3, the air pressure sensor 4, and the micro air valve 5 through a control line. The controller 1 is responsible for receiving the actions of each component and controlling the actions of each actuator. All control logics are running inside the linear rotary actuator 10; the linear motor 2 moves along the linear motor stator 8 and is responsible for vertical movement and force control; the linear motor 2 drives the rotary motor 3 to move in the vertical direction through the connecting plate 9, and the output end of the rotary motor 3 is connected to the suction nozzle 7, which can be used to absorb or release materials; the rotary motor 3 is responsible for rotating and adjusting the material angle in addition to moving in the vertical direction with the linear motor 2. The air guide 6 provides an air source for the suction nozzle 7 and is located on one side of the rotary motor 3 body. The air guide 6 is provided with a micro air valve 5 and an air pressure sensor 4 before passing through the rotary motor 3. The micro air valve 5 is responsible for cutting off the negative pressure air source, and the air pressure sensor 4 detects the air pressure value in the air guide 6 and feeds it back to the controller 1. The linear rotary actuator 10 of the present invention is provided with a micro air valve 5 and an air pressure sensor 4 inside, so that the linear rotary actuator 10 has hardware capabilities. Combined with the control flow of the design software, the linear rotary actuator 10 can automatically complete the material picking and placing.

[0035] like Figure 3 The linear rotary actuator 10 of the present invention is shown as an application topology diagram. The linear rotary actuator 10 has the ability to pick and place materials. The upper controller only needs to give instructions for picking and placing, and the rest of the actions can be automatically completed inside the linear rotary actuator 10; it greatly simplifies the original control topology, greatly reduces the requirements for the upper controller, makes the interactive logic more streamlined, and makes the utilization of the data bus more efficient. The picking strategy of the present invention is as follows Figure 4 As shown, the release strategy is as follows Figure 7 shown.

[0036] Figure 4 The material picking process of the present invention is described, including keeping the micro air valve 5 open at the beginning stage to allow the air duct 6 passing through the rotating motor 3 to have negative pressure airflow. The linear motor 2 is controlled to gently approach and collide with the target material in a soft landing manner. At this time, the controller 1 determines the feedback value of the air pressure sensor 4. When the air pressure value is lower than the preset value A, it means that the material has been sucked. At this time, the controller 1 immediately controls the linear motor 2 to extract and hold the material. The preset value A is determined by the type of material and is not limited again.

[0037] The process of material picking of the present invention is as follows:

[0038] 1. Controller 1 receives the pick-up instruction from the upper controller, and controller 1 controls to open micro air valve 5 to pass negative pressure;

[0039] 2. The controller 1 controls the linear motor 2 to softly land and approach the material;

[0040] 3. The controller 1 determines whether the soft landing of the linear motor 2 is completed. If the soft landing of the linear motor 2 is not completed, the controller 1 enters the timing waiting period until the soft landing of the linear motor 2 is completed. If the timing waiting period exceeds the waiting threshold, the controller 1 checks for faults.

[0041] 4. After the linear motor 2 has soft-landed, determine whether the air pressure value detected by the air pressure sensor 4 is less than the preset value A; if not, enter the timing waiting stage; if the timing waiting stage exceeds the waiting threshold, check for faults;

[0042] 5. If the air pressure value detected by the air pressure sensor 4 is less than the preset value A, the controller 1 controls the linear motor 2 to lift the material and the picking is finished.

[0043] Figure 5 yes Figure 1 The picking time sequence diagram of the traditional system, where S is the target position of the material. From 0 to T1, the linear motor approaches the material at high speed, from T1 to T2, the linear motor approaches the material at low speed, and enters force control after contacting the material at T2. From T2 to T3, the actuator informs the upper controller that it is in place. From T3 to T4, the upper controller inquires about the sensor status and determines that the suction is completed. From T4 to T5, the upper controller informs the actuator that it can return. From T5 to T6, the actuator quickly lifts the material. There are six time periods in total. Picking sequence after using the solution of the present invention Figure 6 As shown, the controller 1 in the linear rotary actuator 10 communicates directly with the air pressure sensor 4, thereby reducing the interaction time of T2 to T5 to Figure 6 The picking sequence of the present invention. From time 0 to T1, the linear motor 2 approaches the material at high speed, from T1 to T2, the linear motor 2 approaches the material at low speed, and enters force control after contacting the material at time T2. Figure 6 After the linear rotary actuator 10 contacts the material at time T2, it can detect the air pressure sensor 4 autonomously, and actively lift the material at time T3 when the suction is completed. The linear motor 2 lifts the material and returns to the initial position from T3 to T4. Figure 1 The control method does not require the interaction time of instructions. Taking 1 ms for an instruction as an example, the picking time in the solution of the present invention can be reduced by at least 3 ms. In addition, there are generally multiple actuators in the upper device, so the overall time saved for picking for the device is 3ms*N (N is the number of actuators).

[0044] Figure 4 After the material is picked up, the external mechanism moves the linear rotary actuator 10 to the position where it needs to be placed. After it is in place, the linear rotary actuator 10 needs to complete an action of releasing the material. The material release process of the present invention is as follows Figure 7 As shown, the specific steps include:

[0045] 1. Controller 1 receives the release command from the upper controller, and controls linear motor 2 to softly land;

[0046] 2. The controller 1 determines whether the soft landing of the linear motor 2 is completed. If the soft landing of the linear motor 2 is completed, the controller 1 controls the micro valve 5 to close the negative pressure. If the soft landing of the linear motor 2 is not completed, the controller 1 enters the timing waiting mode until the soft landing of the linear motor 2 is completed. If the timing waiting mode exceeds the waiting threshold, the controller 1 checks for faults.

[0047] 3. Determine whether the air pressure value detected by the air pressure sensor 4 is greater than the preset value B; if not, enter the timing waiting mode; if the timing waiting mode exceeds the waiting threshold, troubleshoot the fault;

[0048] 4. When the air pressure value detected by the air pressure sensor 4 is greater than the preset value B, the material is released and the controller 1 controls the linear motor 2 to retract.

[0049] The controller 1 controls the software to execute the soft landing process, approaches the target position for placement, and performs force control to maintain the position. The controller 1 recognizes that the soft landing has been completed, and closes the micro valve 5 at this time. After the micro valve 5 is closed, the material will not be adsorbed by the negative pressure and will be released to fall into the target station. After the release, the linear motor 2 is controlled to retract to complete the release of the material. The preset value A in the picking process is less than the preset value B in the release process.

[0050] Figure 8 A traditional material release sequence is demonstrated. 0~T1 The actuator approaches the placement target position at high speed; T1~T2 The actuator approaches at low speed and enters force control at the upper end position at T2; T2~T3 The actuator informs the upper system that the material can be released; T3~T4 The upper system controls the air valve to cut off the negative pressure; T4~T5 The upper system detects whether the air pressure has returned to positive pressure; T5~T6 The upper system notifies the actuator to lift and return to the initial position. It can be seen that there is a relatively complicated process to achieve the release of materials.

[0051] Fig. 9 This is the material release sequence of the method of the present invention, where 0-T1 the linear rotary actuator 10 approaches the target position at high speed; T1-T2 the linear rotary actuator 10 approaches the target position at low speed and contacts the target at T2 to enter force control, and the linear rotary actuator 10 immediately closes the negative pressure of the micro air valve 5 at T2; T2-T3 waits for the air pressure to rise; T3-T4 the linear rotary actuator 10 returns to the initial position at high speed. Figure 8 Compared with the traditional timing, the control strategy for releasing materials in the present invention saves the time used for three processes: the upper system controls the air valve to cut off the negative pressure, the upper system detects whether the air pressure has restored the positive pressure, and the upper system notifies the actuator to lift and return to the initial position, thereby saving the time used for material release.

[0052] In summary, the linear rotary actuator 10 of the control method of the present invention can quickly complete the picking up and releasing of materials, saves communication waiting time compared to traditional control strategies, maximizes action efficiency, improves response speed, and reduces system structure costs.

Claims

1. A material picking and placing method for a linear rotary actuator, the method relates to a linear rotary actuator (10), the linear rotary actuator (10) comprising a controller (1), a linear motor (2), and a rotary motor (3), the linear motor (2) being connected to the rotary motor (3), an air guide tube (6) passing through the rotary motor (3) and then connected to a suction nozzle (7), the air guide tube (6) being connected to a positive and negative pressure air source and being provided with an air pressure sensor (4) and a micro air valve (5), the linear rotary actuator (10) being connected to an upper controller via a high-speed bus, the controller (1) communicating with the linear motor (2), the rotary motor (3), the air pressure sensor (4) and the micro air valve (5), characterized in that: The following steps are included: Step 1: The upper controller issues a picking instruction; Step 2, the controller (1) receives a pick-up instruction and controls the linear rotary actuator (10) to pick up the material; Step 3: The upper controller issues a release command; Step 4: The controller (1) receives the release instruction and controls the linear rotary actuator (10) to release the material.

2. The material picking and placing method of the linear rotary actuator according to claim 1, characterized in that: The specific process of the linear rotary actuator (10) picking up the material in step 2 is as follows:

1. The controller (1) receives a pick-up instruction from the upper controller, and the controller (1) controls the opening of the micro air valve (5) to pass negative pressure; 2. The controller (1) controls the linear motor (2) to softly land close to the material; 3. The controller (1) determines whether the soft landing of the linear motor (2) is completed. If the soft landing of the linear motor (2) is not completed, the controller (1) enters a timing waiting state until the soft landing of the linear motor (2) is completed. If the timing waiting state exceeds a waiting threshold, the controller (1) checks for faults.

4. After the linear motor (2) has completed soft landing, it is determined whether the air pressure value detected by the air pressure sensor (4) is less than a preset value A; if not, a timing wait is started; if the timing wait exceeds a waiting threshold, a fault is checked; 5. If the air pressure value detected by the air pressure sensor (4) is less than the preset value A, the controller (1) controls the linear motor (2) to lift the material, thereby finishing the picking.

3. The material picking and placing method of the linear rotary actuator according to claim 2, characterized in that: The process of releasing the material by the linear rotary actuator (10) in step 4 is as follows:

1. The controller (1) receives a release instruction from the upper controller, and the controller (1) controls the linear motor (2) to perform a soft landing; 2. The controller (1) determines whether the soft landing of the linear motor (2) is completed. If the soft landing of the linear motor (2) is completed, the controller (1) controls the micro air valve (5) to close the negative pressure. If the soft landing of the linear motor (2) is not completed, the controller (1) enters the timing waiting mode until the soft landing of the linear motor (2) is completed. If the timing waiting mode exceeds the waiting threshold, the controller (1) checks for faults.

3. Determine whether the air pressure value detected by the air pressure sensor (4) is greater than a preset value B; if not, enter a timer waiting period; if the timer waiting period exceeds a waiting threshold, troubleshoot; 4. When the air pressure value detected by the air pressure sensor (4) is greater than the preset value B, the material is released and the controller (1) controls the linear motor (2) to retract.

4. The material picking and placing method of the linear rotary actuator according to claim 3, characterized in that: The preset value A is smaller than the preset value B.

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