Robot End Effector Control via Segmented Interaction State Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robots equipped with end effectors often experience improper motion when interacting with objects due to the reliance on motor brakes, leading to inadequate control over interaction states.
Innovation Solution
A robot control method that includes a main control element for specifying limb motion trajectories, a first sub-control element to change interaction states by commanding the actuator, and a second sub-control element to maintain a motion halt state using a brake, allowing proper control of end effectors based on interaction states with the outside world.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a motor with a brake is used to drive the end effector, then the end effector can be driven, but the robot exhibits improper motion when interacting with objects
Solution Approach 1:
The controller is segmented into three independent control elements: a main control element for limb trajectory control, a first sub control element for actuator control to change interaction states, and a second sub control element for brake control to maintain motion halt states. This segmentation allows each control element to independently manage specific aspects of the robot's operation, resolving the contradiction between driving capability and interaction control reliability.
Solution Approach 2:
The system dynamically transitions between different interaction states (first mode and second mode) by coordinating the actuator and brake controls. The controller can switch between driving modes and holding modes based on interaction requirements, enabling the end effector to adapt its behavior dynamically rather than relying solely on the motor brake's static characteristics.
2Stability of the object's composition
If the brake is used to maintain the end effector's motion halt state, then the end effector can be held stationary, but the interaction state control becomes inadequate
Solution Approach 1:
The first sub control element acts as an intermediary between the main control element and the actuator, translating high-level trajectory commands into specific actuator control commands that change interaction states. This intermediary layer enables sophisticated interaction control without compromising the brake's ability to maintain stable motion halt states.
Solution Approach 2:
The system changes interaction mode parameters by coordinating actuator and brake control. When transitioning from a driving state to a holding state, the controller adjusts the brake application timing and duration to achieve the desired interaction outcome, enabling versatile interaction while maintaining stability during holding phases.
3Reliability
If the excitation of the motor is not cut off during malfunction, then the braking torque is maintained, but the end effector's motion control becomes improper
Solution Approach 1:
The second sub control element applies the brake in advance to maintain the motion halt state before potentially switching to a different interaction mode. This preliminary braking action ensures that the end effector is properly positioned and stabilized before the actuator resumes driving, preventing improper motion while maintaining reliable braking torque when needed.
Data Source
AI summary
Provided is a robot and a control method thereof in which the motion of an arm 12 as a specified limb among a plurality of limbs 12 and 14 extended from a body 10 is controlled according to a specified trajectory. If a first interaction state, in which a hand 126, which is an end effector, interacts with a horizontal wood member L (j) of a ladder L in a first mode is implemented, then a control command is given to an actuator 41 that drives the hand 126 to cause the hand 126 to perform a grasping motion, thereby implementing a second interaction state, in which the hand 126 interacts with the horizontal wood member L (j) in a second manner. If the second interaction state is implemented, a control command is given to a brake 42 to maintain a motion halt state of the hand 126.