tailieunhanh - Control of Redundant Robot Manipulators - R.V. Patel and F. Shadpey Part 13

Tham khảo tài liệu 'control of redundant robot manipulators - . patel and f. shadpey part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Numerical Results for Strawman Tasks 173 Segment 1 In this segment the tool frame T is commanded to go to position xp yp Z1 where 1 and J1 are the x and y coordinates of the center of hole 1 as seen in C Z1 is specified to ensure that the peg s head is above the hole s upper surface. The desired orientation is specified such that the x axis of T is aligned with the axis of hole 1 see Figure . Note that because of kinematic errors the position and orientation of the tool frame are different from their desired values. Segment 2 It was noted that due to the presence of different sources of kinematic errors the position and orientation of the tool frame would be different from the desired values at the end of segment 1. In segment 2 the possibility of manually correcting the tool frame position in the x and y directions is given to the operator. This is only required if the kinematic errors are such that the insertion cannot be initiated correctly see Figure . In this case the operator can drag the peg to a position from where the insertion can be initialized. This is done by keeping the orientation and the tool frame s height along the z axis constant while the x and y axes are under force control with zero desired force. In the hardware experiment for Strawman Task II no manual correction was needed. Segment 3 insertion In this segment all axes are under force torque control. In this way the force torque sensor information is used to accurately align the axes of the peg and the hole. Only a negative desired force along the Z axis is specified The desired forces torques for the other axes are zero. Note that no logic branching is required to detect the end of the insertion. The motion is stopped upon completion of the insertion . on achieving the desired interaction force between the peg s flange and the top surface of the hole. Segment 4 removal This segment is similar to segment 3 with the difference that the desired force is in the positive Z .