Linear Motor Robot Arm Kinematics for High Dynamics
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Solution Overview
Problem
Existing robot systems for handling small-mass objects face limitations in dynamics and precision due to distributed actuators in anthropomorphic structures and complex mechanical links in parallel kinematics machines, leading to reduced working speeds, increased costs, and complex control algorithms.
Innovation Solution
A device utilizing a non-conventional kinematic structure with linear electric motors that enable circular and arched movements without supplementary mechanical organs, allowing for high dynamics and precision with simplified control, and featuring ironless linear electric motors for reduced mass and increased flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If traditional actuators with mechanical reducers are used in anthropomorphic robot arms, then torque-speed characteristics are adapted to application requirements, but the distributed actuators increase masses in movement and limit dynamics and working speed
Solution Approach 1:
The patent extracts the actuator from the moving chain and places it in the fixed base zone. The direct-drive actuator is mounted in the fixed support structure, eliminating mechanical reducers and transmitting motion directly to the moving arm through a flexible coupling. This removes the heavy reducer components from the moving parts, significantly reducing the mass that must be accelerated and enabling higher working speeds while maintaining the required torque characteristics.
Solution Approach 2:
The patent replaces the traditional mechanical reducer system with a direct-drive actuator system. Instead of using mechanical gears and reducers to adapt torque-speed characteristics, the system uses a direct-drive motor with a flexible coupling to transmit motion directly. This substitution eliminates mechanical friction, backlash, and the mass of reducer components, improving dynamics and working speed while maintaining control over torque characteristics through electronic control.
2Productivity
If parallel kinematics mechanisms are used to concentrate actuators in the fixed zone, then high dynamic levels are achieved, but the work volume is contained and no-go zones reduce the useful working zone
Solution Approach 1:
The patent segments the robot system into a fixed support zone containing the actuator and a moving arm zone. The actuator remains in the fixed zone while the arm moves freely in the working volume. This segmentation allows the actuator to be positioned optimally for high dynamic performance while the arm can access a larger work volume without being constrained by the actuator's position or creating no-go zones.
Solution Approach 2:
The patent inverts the traditional parallel kinematics approach by placing the actuator in the fixed zone rather than requiring multiple actuators on moving platforms. The single actuator in the fixed support drives the arm through direct transmission, reversing the conventional wisdom and enabling both high dynamics and large work volume without the complexity of multiple actuators creating no-go zones.
3Force
If mechanical reducers are provided with actuators, then torque is increased, but costs increase, maintenance is complicated, structure becomes less rigid, and noise and vibration increase
Solution Approach 1:
The patent extracts the mechanical reducer from the system entirely, replacing it with a direct-drive actuator configuration. The actuator is mounted in the fixed support and connects directly to the arm through a flexible coupling, eliminating the need for complex mechanical reduction mechanisms. This removes the source of noise, vibration, and maintenance complexity while maintaining the required torque output through direct motor selection.
Solution Approach 2:
The patent replaces the mechanical reducer system with an electronically controlled direct-drive system. Instead of using mechanical gears to multiply torque, the system selects an actuator with appropriate torque characteristics and transmits its output directly to the arm. Electronic control replaces mechanical complexity, reducing maintenance requirements, improving rigidity, and eliminating noise and vibration associated with mechanical reducers.
4Productivity
If parallel kinematics robots are used, then high dynamics are achieved, but the structure complexity considerably complicates the realisation of control algorithms
Solution Approach 1:
The patent extracts the actuator from the complex parallel kinematics structure and places it in a simple fixed support configuration. This simplification reduces the system to a single actuator driving a single arm, eliminating the need for complex control algorithms required by parallel kinematics with multiple actuators. The high dynamics are maintained through the direct-drive configuration and flexible coupling, while control complexity is dramatically reduced.
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
The device achieves large work volumes with high dynamics and precision, reduces costs and system complexity, and simplifies control algorithms while maintaining system reliability and control of torque and force.
Implementation Method 1
The means for supporting and moving the first arm comprise at least a first linear electric motor for promoting rotation of the first arm along a circular trajectory and at least a second linear electric motor for promoting oscillation of the first arm along an arched trajectory
Data Source
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AI summary
A device for handling and/or performing work operations on objects comprises: at least a first arm (2) comprising a first end (2a) for supporting a tool (3) for moving or working; means for supporting and moving (4) the first arm (2) which comprise at least a first linear electric motor (5), developing on a closed path (P), for moving the first arm (2) along a circular trajectory (91), and at least a second linear electric motor (6), to which the first arm (2) is directly connected, developing in an arched trajectory (92). The first (5) and the second (6) linear electric motors cooperate to move the first arm (2).