Precision vs. Accuracy: How the Archimedes Drive Delivers Both
For a robot to perform the exact intended movements and be easy to control, it needs to be both accurate and precise. Achieving both requires specific design attributes. The Archimedes Drive excels in this regard, as its high stiffness ensures high accuracy by maintaining the correct position under load. Simultaneously, its true zero backlash enables very precise movements by eliminating any play or delay in motion transfer.
1 – Accuracy vs Precision:
Accuracy: Accuracy refers to the closeness of a robot’s movement or positioning to the true or intended target. It measures how well the robot can achieve the desired position or outcome.
Precision: Precision denotes the consistency and repeatability of the robot’s movements. It measures how consistently the robot can reach the same position multiple times with minimal variation.
Both precision and accuracy are needed for a robot to be easy to operate
2 – High Stiffness – Accuracy
Definition: In the context of a robotic joint, high stiffness refers to the joint’s ability to resist bending, flexing, or twisting under applied forces. It measures how well the joint maintains its shape and position when subjected to external loads, ensuring that the intended motion is accurately executed without deformation.
Impact on Accuracy: High stiffness enhances accuracy by maintaining the intended shape and position under load. This ensures that movements are executed exactly as planned, reducing errors that could lead to deviations from the target position.
Example: Consider a six-axis articulated robotic arm used in welding a car chassis. If the first joint of the arm has low stiffness, the entire movement of the subsequent five joints will be affected.
3 – Zero Backlash – precision
Zero backlash refers to the absence of play or clearance between mating mechanical parts, which ensures that any input motion is transferred to the output motion without delay or lost motion.
Impact on Precision: Zero backlash greatly enhances precision by ensuring that every control input results in an immediate and accurate response. This eliminates any variability or lag in movement, allowing the robot to perform consistently and repeat the same motion with minimal variation.
Example: Consider a SCARA arm used in electronic component placement. If the actuators in the arm have zero backlash, the arm can place components on a circuit board with extreme precision.
Conclusion:
The Archimedes Drive achieves high accuracy through its high stiffness, ensuring the robot’s joints maintain their exact position under load. Simultaneously, the drive offers true zero backlash, eliminating any play or delay in motion transfer, crucial for precision.
This combination allows robots equipped with the Archimedes Drive to execute movements with both exactness and repeatability, making them ideal for tasks that require meticulous control and consistency, such as welding or electronic component placement.
