Robot Gait Phase Variable Shaping for Smoother Foot Contact
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Solution Overview
Problem
The construction of phase variables in gait planning for robots can lead to excessive impact between the swinging leg's foot and the support surface, affecting the stability of the robot's gait.
Innovation Solution
Improving the phase variable in three-dimensional space to reduce the impact on the planned foot of the swing leg when it contacts the support surface, by constructing a second phase variable with a smaller slope using an inverse hyperbolic sine function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the phase variable is constructed in three-dimensional space to enable automatic adjustment of swing time and trajectory, then the robot can maintain stable gait and resist disturbances, but excessive impact occurs between the foot of the swinging leg and the support surface
Solution Approach 1:
The patent modifies the phase variable construction by introducing a scaling factor α that adjusts the rate of change of the phase variable. By changing this parameter, the system reduces the slope of the phase variable near the end of the swing phase, which in turn reduces the impact velocity of the foot upon ground contact while maintaining the stability benefits of phase variable-based control.
2Adaptability or versatility
If the phase variable is used to plan the controlled joints of the robot, then the robot can automatically adjust swing time and trajectory according to disturbance, but the foot of the swinging leg touches the ground in advance causing excessive impact
Solution Approach 1:
The patent introduces a scaling factor α < 1 that modifies the phase variable calculation. This parameter change allows the system to maintain adaptability to disturbances through phase variable-based control while reducing the rate of change of the phase variable near the end of the swing phase, preventing early ground contact and excessive impact.
Data Source
AI summary
A gait planning method for a robot includes: constructing a first phase variable of a gait planning of the robot, wherein the first phase variable is a function of two position components of a torso of the robot on a horizontal plane; constructing a second phase variable based on the first phase variable, wherein the second phase variable is a function of the first phase variable, and a slope of the second phase variable is smaller than a slope of the first phase variable when a foot of a swing leg of the robot starts to touch a support surface; and performing the gait planning on the foot of the swing leg using the second phase variable to obtain a planned trajectory of the foot of the swing leg.