Robotic Exoskeleton Force Control Mode Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exoskeletons require users to wear sensors and interact with interfaces to estimate external forces, making them less ergonomic and limiting their use to complex applications, especially in dynamic or unknown environments.
Innovation Solution
A method and device that allow a robotic device to switch between force control and trajectory control modes, using computer recognition of movements to record external forces and automatically adjust assistance, reducing the need for user-worn sensors and interfaces, enabling more ergonomic and versatile operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If additional indicator elements (sensors, cameras, RFID) are arranged in the environment or on the exoskeleton to estimate external forces, then measurement precision of external forces is improved, but device complexity and ease of operation deteriorate due to requiring user interaction with interfaces and wearing multiple sensors
Solution Approach 1:
The patent extracts the force measurement function from the user-worn sensors and environment-based indicators, and relocates it to the robotic device itself. The robotic device's actuators and motors directly measure interaction forces during trajectory control operations, eliminating the need for separate sensor systems on the user or in the environment.
Solution Approach 2:
The robotic device performs self-measurement of external forces through its own actuators during normal operation. The system uses its motor currents and torque data to infer external forces without requiring external sensors or user interaction, making the system self-sufficient for force estimation.
2Measurement precision
If users directly wear sensors and interact with interfaces to provide force information, then measurement precision of external forces is improved, but ease of operation deteriorates due to reduced ergonomics
Solution Approach 1:
The patent removes all sensor wearing requirements from the user. Force measurement capabilities are extracted from the user side and consolidated into the robotic device, which autonomously measures forces through its actuators during trajectory control without requiring any user sensor wear or interface interaction.
Solution Approach 2:
The robotic device autonomously performs force measurement without user involvement. The system uses its own operational data (motor currents, torques, position changes) to estimate external forces, completely eliminating the need for user-worn sensors or interface interactions.
3Ease of operation
If the exoskeleton operates in force control mode with pre-programmed assistance, then ease of operation is improved, but adaptability to complex and unknown environments deteriorates
Solution Approach 1:
The patent implements dynamic switching between force control and trajectory control modes based on the operational context. The system can transition from pre-programmed force control to autonomous trajectory control with real-time force measurement when operating in unknown or complex environments, providing adaptability while maintaining ease of operation in familiar contexts.
Solution Approach 2:
The system changes its control parameters dynamically by switching between force control mode (with pre-programmed assistance) and trajectory control mode (with autonomous force measurement). This parameter change allows the exoskeleton to adapt to different operational requirements and environmental complexities.
4Adaptability or versatility
If the exoskeleton switches between trajectory control and force control modes, then adaptability to different applications is improved, but device complexity increases due to mode switching mechanisms
Solution Approach 1:
The patent merges the force measurement capability into the trajectory control mode itself. When the robotic device operates in trajectory control, its actuators simultaneously perform position control and force measurement functions. This combining eliminates the need for separate force sensors and simplifies the mode switching architecture.
Solution Approach 2:
The robotic device's actuators serve multiple functions: they perform trajectory control during movement and simultaneously measure external forces during the same operation. This multi-functionality reduces the need for dedicated force sensing hardware and simplifies the overall system architecture.
Data Source
Figure 1~2
Figure 3a~3b
AI summary
The invention relates to a method for assisting at least one movement of a user by means of a robotic device (1), the method allowing the robotic device to be operated in the following two modes: - Default mode: controlling the force of the robotic device via a computer (4) of the robotic device; - Measurement mode: controlling the path of the robotic device, via the computer, and saving in the computer at least one force exerted on the robotic device by an environment that is external to said robotic device in order to implement the force control of the default mode.