ikin(pos, sol_space, ref, ref_pos_opt, iter_threshold)
Features
This function returns the joint position corresponding to sol_space, which is equivalent to the robot pose in the operating space, among 8 joint shapes. Joint position is returned according to closest joint position depend on option(ref_pos_opt). Through status of return value, you can check whether current robot pose is in wrist singularity or out of operating region.
Note
- After SW version V2.9, if the accuracy of the robot is calibrated when using this function, the accuracy correction algorithm operates. The accuracy level can be adjusted according to the option (iter_threshold). Also, there may be a delay of up to 0.1 second depending on the robot posture.
- Refer to ikin_norm() command to find the inverse kinematics solution related to each robot model's well known nominal DH parameters before calibrated DH parameters.
Caution
- If the res_pos_opt parameter is not entered, only pos is returned. Runtime error may occur if ref, status = ikin(...) is used without entering the ref_pos_opt parameter.
Parameters
Parameter Name | Data Type | Default Value | Description |
pos | posx | - | posx or position list |
list (float[6]) | |||
sol_space | int | - | solution space |
ref | int | DR_BASE | reference coordinate
|
ref_pos_opt | int | 0 | Determine closest joint position depend on option among multi turn solutions
|
iter_threshold | list (float[2]) | 0.005 | If the accuracy has been corrected, the level of the accuracy correction algorithm The norm value of TCP position (X, Y, Z) [mm] |
0.01 | If the accuracy has been corrected, the level of the accuracy correction algorithm The norm value of TCP orientation (A, B, C) [deg] |
Robot configuration vs. solution space
Solution space | Binary | Shoulder | Elbow | Wrist |
0 | 000 | Lefty | Below | No Flip |
1 | 001 | Lefty | Below | Flip |
2 | 010 | Lefty | Above | No Flip |
3 | 011 | Lefty | Above | Flip |
4 | 100 | Righty | Below | No Flip |
5 | 101 | Righty | Below | Flip |
6 | 110 | Righty | Above | No Flip |
7 | 111 | Righty | Above | Flip |
Return
| Value | Description |
|---|---|
posj | Joint space point |
status |
|
Exception
| Exception | Description |
|---|---|
DR_Error (DR_ERROR_TYPE) | Parameter data type error occurred |
DR_Error (DR_ERROR_VALUE) | Parameter value is invalid |
DR_Error (DR_ERROR_RUNTIME) | C extension module error occurred |
DR_Error (DR_ERROR_STOP) | Program terminated forcefully |
Example
x1 = posx(370.9, 719.7, 651.5, 90, -180, 0)
q1, status = ikin(x1, 2, DR_BASE, ref_pos_opt=0) # Joint angle q1 where the coordinate of the robot edge is x1 (second of 8 cases), reference joint position : posj(0,0,0,0,0,0)
# q1=posj(60.3, 81.0, -60.4, -0.0, 159.4, -29.7) (M1013, tcp=(0,0,0))
movej(q1,v=10,a=20)