LAUSR

The peg-in-hole method using the compliance characteristics of robots has advantages in terms of cost and speed compared to conventional methods based on contact force feedback with force/torque sensors. In our previous study, we proposed a compliant peg-in-hole assembly method based on blind searching using a spiral force trajectory (SFT). The main drawback of this method was the deviation of the completion time for assembly tasks. Therefore, in this study, we analyzed the efficiency of the SFT and developed an improved trajectory called the partial spiral force trajectory (PSFT). The proposed PSFT method reduced the variance of the elapsed time by eliminating the uncertainty in the time required to find the hole. To verify the performance of the proposed strategy, simulations and experiments with round, square, and triangular pegs were conducted. The results confirmed that the proposed method reduced the standard deviation and mean of the elapsed time up to 91.7% and 30.8%, respectively, compared to those obtained in our previous method using the SFT.