Multi-joint robot motion track position information pulse coding signal sending method

Abstract

The invention belongs to the technical field of robot motion control, and particularly relates to a multi-joint robot motion track position information pulse coding signal sending method. Comprising the following steps: step 1, compiling a scanning track according to the characteristics of a scanned object; 2, the controller carries out inverse operation to solve a corresponding joint angle; 3, adding 2-axis position information in the track coordinates into a joint angle sequence; 4, the two-axis position information and the joint angle instruction are sent to the corresponding drivers together; step 5, the position output driver outputs the received position instruction in an A / B phase form through a simulation coding interface; and step 6, the position coding interface of the flaw detector receives A / B phase signals from the driver. The device has the beneficial effects that the movement track can be accurately represented, and the flaw detector can receive position information in real time without errors.

Description

Technical Field

[0001] This invention belongs to the field of robot motion control technology, specifically relating to a method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot. Background Technology

[0002] When performing non-destructive testing, the flaw detector scans the surface of the workpiece with a probe. It needs to read the probe's current position to confirm the precise location of the flaw detection result. To ensure synchronization between the detection signal and position information, the flaw detector typically obtains position information by receiving pulse-coded signals sent from the control system.

[0003] If the workpiece has a simple planar structure, a corresponding two-axis scanning tool can be used. The two motion axes of the scanning work represent the X and Y coordinates of the workpiece, respectively. In this case, the position encoding signals of the two motion axis motors are directly sent to the flaw detector.

[0004] Most workpiece surfaces are not simple planes, and two-axis scanning tools cannot achieve the required close contact with the workpiece surface. In such cases, multi-joint robotic arms are necessary. The flexibility of multi-joint robotic arms allows the probe to fully contact the workpiece surface. Because the motion is achieved by the simultaneous movement of multiple joints, the position coordinates of the workpiece surface cannot be directly expressed by the angles of certain joints; therefore, position coordinate information needs to be synthesized. Position synthesis calculations typically introduce issues of accuracy and latency.

[0005] When the controller issues motion commands, it sends the joint angle information and the two-axis coordinate information of the workpiece surface together. After receiving the coordinate information, the pulse code driver converts it into an A / B phase encoded signal for output. The flaw detector receives the encoded information from the pulse code driver. Summary of the Invention

[0006] The purpose of this invention is to provide a method for transmitting pulse-coded signals of position information in the motion trajectory of a multi-joint robot. This method is used to transmit position information in the motion trajectory of a multi-joint robot. The motion trajectory of the multi-joint robot is calculated into a two-axis motion, and the position information of this two-axis motion is sent to the driver via a command. Then, the driver simulates the position command into pulse codes and sends them out.

[0007] The technical solution of the present invention is as follows: A method for transmitting pulse-coded signals of motion trajectory position information of a multi-joint robot, comprising the following steps:

[0008] Step 1: Based on the characteristics of the objects being scanned, create a scanning trajectory;

[0009] Step 2: The controller performs inverse calculations to determine the corresponding joint angles;

[0010] Step 3: Add the position information of the two axes in the trajectory coordinates to the joint angle series;

[0011] Step 4: Send the 2-axis position information and joint angle commands to the corresponding drivers;

[0012] Step 5: The position output driver outputs the received position command in A / B phase form through the simulation encoding interface;

[0013] Step 6: The flaw detector's position encoding interface receives the A / B phase signal from the driver.

[0014] In step 1, a scanning trajectory is compiled based on the characteristics of the object being scanned. For cylindrical objects, the starting and ending φ and z coordinates are input during the trajectory process, and the scanning direction and step value are determined to generate a rectangular scanning trajectory, including the coordinate values ​​of each point during the probe's movement.

[0015] In step 2, the controller performs inverse calculation to determine the corresponding joint angles. The controller first converts the coordinate values ​​of the cylindrical coordinate system where the cylinder is located into coordinate values ​​in the coordinate system where the robot arm is located, and then performs inverse calculation to determine the corresponding robot arm joint angles.

[0016] In step 3, the position information of the two axes in the trajectory coordinates is added to the joint angle sequence: the six joint angle sequences have only six values, and the corresponding φ and z values ​​are also added to the sequence to form a sequence with eight values ​​(θ1, θ2, θ3, θ4, θ5, θ6, φ, z).

[0017] In step 4, the 2-axis position information and joint angle command are sent to the corresponding driver: a sequence of 8 values ​​(θ1, θ2, θ3, θ4, θ5, θ6, φ, z) is sent to the corresponding driver.

[0018] In step 5, the position output driver outputs the received position command in A / B phase form through the simulation encoding interface: the driver has a simulation encoding output function and outputs the position information of the received control command register in A / B phase form.

[0019] In step 6, the flaw detector position encoding interface receives the A / B phase signal from the driver and puts the position information and the probe signal information at this time into the same register to determine the position of the probe signal in the scanning trajectory and its position in the physical inspection object.

[0020] The beneficial effects of this invention are: it can accurately represent the motion trajectory, and the flaw detector can receive position information in real time and without errors. The inverse kinematic operation from coordinate points to various joint angles typically has only numerical solutions, not analytical solutions. These numerical solutions contain errors depending on their convergence conditions. If the numerical solutions are then used for forward kinematic calculations to obtain coordinate values, not only will there be accumulated errors, but there will also be time delays. This invention, by notifying the driver to send joint angles and coordinate values, ensures that there is no calculation delay between the coordinate values ​​and joint angles, resulting in better real-time performance and accuracy. Attached Figure Description

[0021] Figure 1 The flowchart illustrates a method for transmitting pulse-coded signals to provide position information of a multi-joint robot's motion trajectory, as provided in this invention. Detailed Implementation

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1 As shown, a method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot includes the following:

[0024] Step 1: Based on the characteristics of the objects being scanned, create a scanning trajectory;

[0025] Based on the characteristics of the object being scanned, a scanning trajectory is created: taking a cylindrical object as an example, simply input the start and end φ and z coordinates when creating the trajectory, and simultaneously determine the scanning direction and step value to generate a rectangular scanning trajectory, with the coordinate values ​​of each point during the probe's movement (in the cylindrical coordinate system where the cylinder is located).

[0026] Step 2: The controller performs inverse calculations to determine the corresponding joint angles;

[0027] The controller performs inverse calculations to determine the corresponding joint angles: First, the controller converts the coordinates of the cylindrical body to the coordinates of the robot arm, and then performs inverse calculations to determine the corresponding joint angles of the robot arm. For a 6-joint robot arm, these are the 6 joint angles (θ1, θ2, θ3, θ4, θ5, θ6). To ensure the uniqueness of the calculated values, some constraints are usually set here.

[0028] Step 3: Add the position information of the two axes in the trajectory coordinates to the joint angle series;

[0029] Add the 2-axis position information from the trajectory coordinates to the joint angle sequence: the 6 joint angle sequence only has 6 values, so we also add the corresponding φ and z values ​​to the sequence to form a sequence with 8 values ​​(θ1, θ2, θ3, θ4, θ5, θ6, v, z).

[0030] Step 4: Send the 2-axis position information and joint angle commands to the corresponding drivers;

[0031] The two-axis position information, along with joint angle commands, is sent to the corresponding drivers: a sequence of eight values ​​(θ1, θ2, θ3, θ4, θ5, θ6, φ, z) is sent to the corresponding drivers. Our 6-joint robot control system is configured with eight drivers. The first six drivers correspond to the control of joints 1-6, while drivers 7 and 8 are used to send position information from the scanning probe.

[0032] Step 5: The position output driver outputs the received position command in A / B phase form through the simulation encoding interface;

[0033] The position output driver outputs the received position commands in A / B phase form through the simulation encoding interface: The driver we selected has a simulation encoding output function, which can output the position information of the received control command register in A / B phase form.

[0034] Step 6: The flaw detector's position encoding interface receives the A / B phase signal from the driver.

[0035] The flaw detector position encoding interface receives the A / B phase signal from the driver: The flaw detector position encoding interface receives the A / B phase signal from the driver and puts the position information and the probe signal information at this time (the numerical value after AD conversion) into the same register to ensure the correspondence between the probe signal and the position, thereby determining the position of the probe signal in the scanning trajectory, and then determining its position in the physical inspection object.

Claims

1. A method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot, characterized in that, Includes the following steps: Step 1: Based on the characteristics of the objects being scanned, create a scanning trajectory; Step 2: The controller performs inverse calculations to determine the corresponding joint angles; Step 3: Add the position information of the two axes in the trajectory coordinates to the joint angle series; Step 4: Send the 2-axis position information and joint angle commands to the corresponding drivers; Step 5: The position output driver outputs the received position command in A / B phase form through the simulation encoding interface; Step 6: The flaw detector's position encoding interface receives the A / B phase signal from the driver.

2. The method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot as described in claim 1, characterized in that: In step 1, a scanning trajectory is compiled based on the characteristics of the object being scanned. For cylindrical objects, the starting and ending φ and z coordinates are input during the trajectory process, and the scanning direction and step value are determined to generate a rectangular scanning trajectory, including the coordinate values ​​of each point during the probe's movement.

3. The method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot as described in claim 1, characterized in that: In step 2, the controller performs inverse calculation to determine the corresponding joint angles. The controller first converts the coordinate values ​​of the cylindrical coordinate system where the cylinder is located into coordinate values ​​in the coordinate system where the robot arm is located, and then performs inverse calculation to determine the corresponding robot arm joint angles.

4. The method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot as described in claim 1, characterized in that: In step 3, the position information of the two axes in the trajectory coordinates is added to the joint angle sequence: the six joint angle sequences have only six values, and the corresponding φ and z values ​​are also added to the sequence to form a sequence with eight values ​​(θ1, θ2, θ3, θ4, θ5, θ6, φ, z).

5. The method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot as described in claim 1, characterized in that: In step 4, the 2-axis position information and joint angle command are sent to the corresponding driver: a sequence of 8 values ​​(θ1, θ2, θ3, θ4, θ5, θ6, φ, z) is sent to the corresponding driver.

6. The method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot as described in claim 1, characterized in that: In step 5, the position output driver outputs the received position command in A / B phase form through the simulation encoding interface: the driver has a simulation encoding output function and outputs the position information of the received control command register in A / B phase form.

7. The method for transmitting pulse-coded signals for the motion trajectory position information of a multi-joint robot as described in claim 1, characterized in that: In step 6, the flaw detector position encoding interface receives the A / B phase signal from the driver and puts the position information and the probe signal information at this time into the same register to determine the position of the probe signal in the scanning trajectory and its position in the physical inspection object.

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