Trajectory generation schemes for bipedal ascending and descending stairs using univariate dynamic encoding algorithm for searches (uDEAS)

Abstract

In this paper, we propose new motion schemes for a biped robot to walk up and down a staircase using dynamic encoding algorithm for searches (DEAS) for optimization. Ascending and descending a staircase are scheduled by four phases for convenience of motion generation. Each phase mimics the natural gait of a human being and is easy to analyze and implement. Optimal trajectories of 10 joint motors in a lower extremity of a humanoid are computed to simultaneously satisfy stability conditions, walking constraints, and energy efficiency requirements, and the zero moment point condition. The performance of uDEAS is compared to genetic algorithm in finding 13 parameters with the result that uDEAS requires only 17 seconds, which is 12 times faster. The feasibility of the proposed motion schemes is validated with computer simulations and experiments successfully carried out for a small humanoid robot.

Walking with perturbations: a guide for biped humans and robots

“…The equivalent of humans walking with a foot-in-hole has not been tested systematically in biped robots but some attempts were made to add sensors to the feet to enable walking on uneven terrain [269]. In contrast, several groups have tackled the issue of stair descend, which is particularly challenging as it requires lateral tilting [270][271][272]. Probably most spectacular is the stair descend of robots such as Asimo [273].…”

Online Joint Trajectory Generation of Human-like Biped Walking

“…For the generation of arbitrary walking motions, it is necessary to describe a robot's motion with respect to its joint spaces based on kinematic relationships. This work is based on a newly completed 3-D whole-body model of a humanoid using both the Denavit-Hartenberg (DH) convention [14] and the projection principle [8] for the DARwIn-OP platform, as shown in Figure 1, where the double-scripted symbols (such as l c i and l s i ) denote the length of the i -th link projected on the coronal plane and the sagittal plane, respectively. M i and ( X i , Y i , Z i ) represent the point mass of the i -th link and the world coordinate of the i -th joint, respectively.…”

“…Owing to the dynamically adapted upper and lower boundaries of the search variables, PSO succeeds in locating local minima within five seconds. This search time is reduced to one second when the projection-based humanoid modelling in [8] is used, which is nearer to real-time.…”

“…From the viewpoint of robotics theory, dynamic walking strategies has been developed in relation to offline walking pattern generation, online pattern adjustment, and real-time balance control [7][8][9][10][11]. In general, basic patterns are designed offline by planning the zero moment points (ZMPs) of the humanoid to be placed inside the convex hull of the stance foot while walking [7] and ascending/descending stairs [8]. For online pattern adjustment, the cycloid function and third-order polynomial interpolation are employed to describe the reference position trajectories of the swing leg's ankle and centre of pelvis, respectively [9].…”

Topology Optimization Design Parameter Enhanced by Univariate Dynamic Encoding Algorithm for Searches

“…Optimization methods can be categorized into two approaches; indirect and direct methods as termed in [11]. Among them, the approach using a univariate dynamic encoding algorithm for searches (uDEAS) [12], [13] was used for multiple optimization problems and was used for corresponding hyper-parameter tuning. This algorithm was used to optimize various control parameters such as fuzzy parameter of a robot controller [14], motor parameter estimation [15], billet temperature estimation [16], as well as finding a high-dimensional optimization problem quickly global optimal point.…”