On the Dynamic Optimization of Biped Robot

Abstract

Abstract-This paper concentrates on three important points: the selection of the suitable direct method used for suboptimal control of the biped robot, the selection of the appropriate nonlinear programming (NLP) algorithm that searches for the global minimum rather than the local minimum, and the effect of different constraints on the energy of the biped robot. To perform the mentioned points, the advantages and disadvantages of the optimal control methods were illustrated. The inverse-dynamics based optimization is preferred because of the ability to convert the original optimal control into algebraic equations which are easy to deal with. The inverse-dynamics-based optimization was classified as spline and the finite difference based optimization. Due to the easy use of the latter, it was used for investigating seven cases with different constraints for 6-DOF biped robot during the single support phase (SSP). Hybrid genetic-sequential quadratic programming (GA-SQP) was used for simulation of the target robot with MATLAB. It can be concluded that more imposed constraints on the biped robot, more energy is needed. In general, more energy can be required in the case of (1) restriction of the swing foot to be level to the ground and (2) reducing the hip height or constraining the hip to move in constant height.Index Terms-Biped robot, dynamic optimization suboptimal control, walking patterns.

Decentralized adaptive partitioned approximation control of high degrees-of-freedom robotic manipulators considering three actuator control modes

“…See [48,49] for more details. Figure 9 shows the configuration of the biped robot during the SSP; for more details on modeling and control of biped robots see [47][48][49][50][51][52][53][54][55][56][57]. The physical parameters are borrowed from [58].…”

“…The ZMP location coincides with the location of the center of pressure for the balance walking; however, this is not the case for unbalanced walking. See[47][48][49][50][51][52][53][54][55][56][57] and the references therein for more details.…”

Multi-level control of zero-moment point-based humanoid biped robots: a review

“…Offline walking patterns do not need multi-level controllers, because they have been prepared in advance to satisfy the dynamic/kinematic constraints. 65,69,70,102 It needs only low-level control to track the desired angular joint trajectories.…”

A Simple Algorithm for Generating Stable Biped Walking Patterns

“…Numerous approaches have been used to generate the motion of biped robot. However, there are three efficient methods have been used successfully for this purpose: Optimization-based gait, COG-based gait and the interpolation-based gait [5][6][7][8]; see the references therein. Despite the miscellaneous walking pattern generation and stabilization approaches, it is difficult to find a thorough method that can tune the walking parameters to satisfy the kinematic and dynamic constraints: singularity condition at the knee joint, zero-moment point (ZMP) constraint, and unilateral contact constraints.…”