Bird-like Robot Leg with Spring-Damper Compliance
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Solution Overview
Problem
Current robotic systems fail to effectively imitate the running and jumping movements of birds, which require unique stability and control mechanisms different from human running principles.
Innovation Solution
A mobile robot leg arrangement featuring a torso and leg segments connected by a middle joint, allowing pivoting and stretching, with a spring-damper unit for energy efficiency and stability, and a foot design with multiple ground contact points for enhanced stability and control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If active rigid body mechanisms are used for walking robots, then locomotion capability is achieved, but energy consumption is high and control complexity increases
Solution Approach 1:
The patent changes the physical parameters of the leg mechanism by introducing passive compliance elements (springs and dampers) and variable length capability. The leg can transition between extended and retracted states passively, changing its mechanical properties to match different phases of the bird-like gait cycle, thereby reducing energy consumption and control complexity
Solution Approach 2:
The leg mechanism performs self-regulation through passive elements. The spring-damper system automatically absorbs and releases energy during the gait cycle, and the variable length mechanism passively adjusts leg configuration based on ground reaction forces, eliminating the need for active control during critical phases of movement
2Reliability
If bird-like running movements are imitated, then stability and energy efficiency are improved, but the mechanism complexity increases
Solution Approach 1:
The leg is segmented into multiple functional components: upper and lower leg segments, spring-damper units, and variable length mechanisms. This segmentation allows each component to perform a specific function (energy storage, shock absorption, length adjustment) that collectively achieves bird-like stability without requiring complex overall system design
Solution Approach 2:
The spring-damper units and variable length mechanisms serve multiple functions simultaneously: they provide energy storage and release, shock absorption, passive leg length adjustment, and stability control. This multi-functionality reduces the need for separate dedicated mechanisms, thereby limiting the increase in overall complexity
3Productivity
If variable leg length is implemented, then running efficiency is improved, but the device complexity increases
Solution Approach 1:
The leg length is made dynamically adjustable through passive variable length mechanisms that respond to ground reaction forces and gravitational effects. The leg automatically transitions between extended and retracted configurations during the gait cycle, enabling efficient running without requiring active control systems
Solution Approach 2:
Passive mechanical elements (springs, dampers, and linkage mechanisms) serve as intermediaries that mediate the length adjustment process. These intermediaries translate ground reaction forces into automatic leg length changes, eliminating the need for direct active control while achieving efficient variable length operation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables the robot to mimic bird-like running and jumping movements with minimal energy consumption and reduced control effort, offering improved stability and efficiency compared to actuated rigid-body walking systems.
Implementation Method 1
The upper leg segment can be shortened in relation to the torso joint via a spring-damper unit by a force acting between the upper leg segment and the torso joint
Implementation Method 2
spring-damper unit
Data Source
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AI summary
The invention relates to a mobile robot, which is suitable for performing running/walking movements known from nature and comprises two leg assemblies, each having a leg (02) and a trunk part (01). The leg (02) comprises an upper leg segment (03) and a lower leg segment (04), which are connected to each other by a center joint (06). The upper leg segment (03) and the lower leg segment (04) can be extended relative to each other by an extending drive (18) by means of the center joint (04). The upper leg segment (03) is mounted in a trunk joint on the trunk part (01) and can be swung relative to the trunk part (01) in a running/walking direction by means of a leg swing drive (08, 09, 11). The trunk joint can be translated relative to the trunk part (01) by means of a leg retraction drive (12, 14, 16). The upper leg segment (03) can be shortened with respect to the trunk joint by means of a spring-damper unit (07). The leg (02) has, on the lower leg segment (04), a foot (26) extending in a surface. The invention further relates to a method for performing a running/walking movement by means of a leg assembly according to the invention.