What factors determine the flexibility of an industrial robot? As we all know, the most important factor is the number of axes. The number of robot axes determines its degrees of freedom. The higher the degrees of freedom, the closer the robot is to the human hand's movement functions, and the better its versatility. However, the more degrees of freedom there are, the more complex the structure, and the higher the overall requirements for the robot. This is a contradiction in robot design.
This collaborative robot with degrees of freedom features functions such as rapid configuration, traction teaching, visual guidance, and collision detection.
Indispensable – Servos and Sensors
Collaborative robots make human-robot collaboration easier and safer by sensing and reacting to minute changes in external torque.
1. Ultra-compact, powerful servo drive
A single actuator is small enough to be directly mounted on the robot joint, ensuring a compact and efficient robot design. Mounting the servo actuator directly on the joint, and placing it close enough to the encoder feedback, saves on cabling, reduces interference, and achieves lower EMI and RFI levels, significantly improving system stability. Another feature that makes integration easier is the actuator's inherent robustness, allowing it to withstand extremely high mechanical acceleration and deceleration within the joint.
2. Dual closed-loop control algorithm
The dual-closed-loop control algorithm can improve the performance of the servo motor to achieve optimal performance. Each axis in the system employs a dual-closed-loop control algorithm to improve the positioning accuracy of the joint ends at the rear end of the reducer. Incremental encoders and Hall elements are placed at the front end of the reducer as speed loop feedback, while a 19-bit high-resolution absolute encoder serves as the load end position feedback.
3. Motion redundancy
Kinematic redundancy is useful for operating multiple robots within a specific space because motion interference is easily handled. Six degrees of freedom is the minimum number of degrees of freedom required to perform spatial positioning; robots with more than six axes are collectively referred to as redundant degree-of-freedom robots. Compared to traditional 6-joint robots, 7-joint robots can extend their robotic arms at multiple angles to approach a specific component. Redundant degree-of-freedom robots have more advantages in obstacle avoidance, overcoming singularities, flexibility, and fault tolerance; therefore, industrial robots with redundant degrees of freedom will have more applications in complex working environments.
4. Torque sensor
In human-robot collaborative environments, these robots are tasked with high-speed, high-precision tasks. Using cameras, force sensors, and other sensing elements, the robots can detect the presence of humans and take appropriate actions to avoid harm. In some cases, torque sensors are placed behind the motor gearbox to directly detect any rapid increases in external torque; in others, the robot needs to output a certain torque to lift loads or move loads from one location to another. When the robot detects an abnormal increase in torque during movement, such as a collision, it will automatically stop.
5. Safety sensors
For industrial robots to collaborate with humans, the first step is to find ways to ensure worker safety. These sensors come in various forms, from cameras to lasers, but their purpose is the same: to inform the robot about its surroundings. A simple example is the laser safety sensor on an elevator door. When the laser detects an obstacle, the door immediately stops closing and retracts to avoid a collision. Most safety sensors in the robotics industry work similarly.
6. Parts inspection sensors
In parts picking applications (assuming no vision system), you cannot know whether the robotic gripper has correctly picked up the parts. Part inspection applications, however, can provide feedback on the gripper's position. For example, if the gripper misses a part, the system will detect the error and repeat the process to ensure the part is picked up correctly.
