Position encoders play a crucial role in robotic systems by providing precise measurement of position, offering vital feedback on the movements of actuators, joints, and other components. In applications where ultra-precise position feedback is paramount, optical encoders utilizing glass scales stand out, delivering unparalleled performance.
Encoders, comprising a sensor and a scale, measure position changes as the scale moves either linearly or rotationally. While inductive encoders find favor in specific environments, optical encoders, particularly in applications like surgical robotics requiring high accuracy, are preferred. Optical encoders use photosensitive sensors to detect position changes relative to the scale, employing various technologies such as transmitted light, reflected light, or coherent light interference (talbot imaging). These encoders often feature an index mark on the scale for zero-point detection.
Glass scales, as opposed to metal scales, offer distinct advantages in precision applications. Metal scales, common in cost-driven scenarios, provide reasonable accuracy with laser-etched lines. However, glass scales, due to their increased rigidity, allow for higher precision through techniques like laser etching or chrome deposition, minimizing irregularities. Another significant advantage of glass is its lower coefficient of thermal expansion, reducing the impact of heat-induced expansion in high-precision robotics applications compared to metal scales.
While cost-driven applications may opt for metal scales, glass scales are the preferred choice for those prioritizing precision. In high-precision scenarios where accuracy is critical, the rigidity and thermal properties of glass scales make them the optimal selection, ensuring reliable and accurate performance in demanding robotic applications.