Understanding Accuracy in Ultra Precision Motion Control Systems

As a manufacturer of ultra precision motion control systems, ALIO knows that it’s crucial to delineate the concepts of accuracy and precision, their importance, and their interplay. These concepts are fundamental in our industry and can significantly impact the performance and outcomes of our products.

Accuracy in motion control systems refers to the degree to which the position of a controlled element aligns with its intended target or the true value. It’s a measure of how close a system can bring an object to a desired point, considering all possible errors in measurement and movement. For instance, if a motion control system is tasked with positioning an object at a specific coordinate, its accuracy would be determined by how closely the object reaches this coordinate within the tolerance limits.

Accuracy is paramount in applications requiring high precision, such as semi-conductor manufacturing, optical device assembly, and medical device fabrication. In these industries, even the slightest deviation from the intended position can lead to significant defects or malfunctions. Therefore, accurate motion control systems ensure that every movement and position is within the stringent tolerances necessary for high-quality production.

While accuracy refers to the closeness to the true value, precision relates to the repeatability or consistency of measurements. Precision is about the system’s ability to reproduce the same position or measurement under the same conditions multiple times. A system can be precise without being accurate if it consistently hits the same point that is not the target. Conversely, a system can be accurate on average but imprecise if its positions vary widely around the target.

Focusing solely on accuracy can be misleading because it does not provide a complete picture of the system’s performance. A system might have high accuracy but low precision, meaning it hits the target correctly but does not do so consistently. This inconsistency can result in variations in the quality of the manufactured products, which is unacceptable in high-precision industries.

For example, in semi-conductor manufacturing, both accuracy and precision are crucial. A motion control system must consistently place components at the exact locations required. If the system is accurate but not precise, the variability in component placement can lead to defects, reducing the overall yield and increasing costs.

For manufacturers of ultra precision motion control systems like ALIO, both accuracy and precision are recognised as essential. Accuracy ensures the system can hit the desired target, while precision guarantees that it can do so consistently. Understanding and communicating both aspects to our customers is critical to ensure they have a comprehensive view of the system’s capabilities. By doing so, we can help them make informed decisions, leading to optimal performance and quality in their applications.