Robot Controller Torque Optimization for Power Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Robot apparatuses face challenges in executing flexible motions while minimizing electric power consumption, often resulting in increased energy usage and reduced ability to safely interact with obstacles due to constrained motion control systems.
Innovation Solution
A robot apparatus with a controller that uses a cost function to minimize electric power consumption by classifying joint axes into independent and dependent axes, calculating optimal torque reference inputs, and adjusting control gains based on motion environment and importance weights, allowing for flexible and safe motion execution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If motion reference input from a user constrains the motions of various joint axes of the robot, then the robot can execute desired motions, but the electric power consumption of the robot increases and the robot becomes unable to flexibly contact obstacles around the robot
Solution Approach 1:
The patent segments the control of joint axes by classifying them into independent axes and dependent axes. The independent axes are directly controlled by torque reference inputs, while the dependent axes are controlled through position reference inputs derived from the independent axes. This segmentation allows the robot to execute desired motions while minimizing power consumption by only actively controlling the necessary independent axes.
Solution Approach 2:
The patent implements dynamic control gain adjustment where the control gains for dependent axes are changed based on the robot's operational state. When the robot needs to contact obstacles, the control gains are adjusted to allow more flexible motion. This dynamic adjustment enables the robot to adapt its control stiffness in real-time, reducing power consumption during normal operation while maintaining flexibility when needed.
2Reliability
If control gains of a servo-control system are changed to achieve soft contact, then the robot can safely contact obstacles, but the motions of axes of the robot are constrained and the electric power consumption increases
Solution Approach 1:
The patent dynamically adjusts control gains based on the robot's operational context. During obstacle contact, control gains are modified to enable soft and safe interaction. During normal motion execution, the control gains are optimized for power efficiency. This dynamic adjustment allows the system to achieve safe contact capability without continuously consuming excessive power.
Solution Approach 2:
The patent applies different control strategies to different axes based on their role. Independent axes receive torque control for precise motion execution, while dependent axes receive position control with dynamically adjusted gains for safe interaction. This localized differentiation allows the robot to achieve safe contact capability only where needed (in dependent axes) without compromising overall power efficiency.
3Power
If the robot apparatus frequently charges the battery due to increased electric power consumption, then the robot can maintain operation, but the operational continuity is reduced and charging frequency increases
Solution Approach 1:
By segmenting the control into independent and dependent axes, the patent reduces the overall power consumption of the robot system. The independent axes are controlled with torque inputs that minimize energy use, while dependent axes use position control that is only activated when needed. This segmentation leads to reduced battery consumption and extended operational continuity between charges.
Solution Approach 2:
The patent changes control parameters (control gains) based on operational requirements. By optimizing control gains for power efficiency during normal operation and only adjusting them for safe contact when necessary, the system minimizes overall power consumption and extends battery life, thereby improving operational continuity.
Data Source
AI summary
A robot apparatus includes a robot mechanism having a plurality of joints, and actuators that drive joint axes of the robot mechanism. The robot apparatus includes a robot controller that controls the driving of the actuators based on a cost function that is a function of torque reference inputs for the actuators.