Measurement and inspection equipment yields inaccurate results
Machining dimensions on machine tools exceed tolerances
Alignment deviation
…
If you have encountered any of these issues,
there is a good chance that position control is not precise enough!
Precision is the cornerstone of any motion control system. Modern industry's pursuit of efficiency, quality, and consistency has pushed position control accuracy to unprecedented heights. In this precision race, the encoder has always played the role of the "unsung hero." Although it is hidden deep within the equipment, it carries the core mission of providing high‑precision position feedback. If we liken a motion control system to a "human body" and the controller to the "brain," then the encoder is the "eyes" of the motion control field! Just as humans rely on visual feedback to accurately perform actions like grasping and walking, industrial equipment relies on real‑time, accurate position feedback from encoders to form a closed‑loop control, thereby precisely driving motors or actuators to reach predetermined positions.
Only when the encoder's "eyesight" is sharp and precise enough can the accuracy of the entire system be effectively guaranteed. Especially in high‑end industries such as semiconductors, display panels, electronics, and medical devices, where processes involve micron‑ or even nanometer‑level position movements, the requirements for encoder accuracy and stability are even more stringent.
1) Why Does Motion Control Need Precise Position Feedback?
Most modern control systems are "feedback control" systems. That is: you give a command (e.g., press a button), the system executes the action (e.g., the motor starts turning), and at the same time the system continuously "looks back" in real time—feeding the execution results back to the controller, which then judges whether the action was performed correctly and adjusts if not. There are many forms of feedback, including limit switches, temperature sensors, etc. Position feedback is one type of feedback information, used to monitor or adjust position and speed.
There are various means to obtain position feedback, including encoders, displacement sensors, and even laser distance sensors. Among them, the encoder is a critical position feedback component. Essentially, it is a sensor that converts mechanical motion into electrical signals and transmits data to other devices, providing the controller with feedback such as "where it is now" and "how fast it is moving." Taking an optical encoder as an example, its working principle includes a read head and a scale. The read head reads the graduations on the scale, converting them into periodically varying electrical signals, which are then counted by back‑end signal acquisition equipment to determine the position of the motion axis.
1) What Are the Consequences of Imprecise Position Control?
As the "eyes" of the closed‑loop system, if the encoder's "vision" deteriorates—data deviations or signal loss—the entire system's judgment will be severely biased, manifesting as:
l Inability to reach the target position
Take industrial robots as an example. Rotary encoders provide real‑time feedback of joint angles, which is the basis for precise movements. If the feedback data is distorted, the robot will deviate when grasping objects, affecting operational quality.
l Reduced system stability and reliability
In new energy vehicle battery manufacturing equipment, encoders must be extremely stable and reliable to ensure high production yield. If an encoder fails or data becomes abnormal, the entire production line may be forced to stop, increasing material waste.
l Reduced safety
Surgical robots demand extremely high system safety. Any minor error in the encoder can have a fatal impact on operational precision, directly threatening patient safety.
l Impaired production efficiency and cost
In semiconductor manufacturing, wafer materials are extremely expensive, and high yield is crucial. Encoders must not only run stably in harsh environments such as vacuum and high temperature, but also maintain extremely high precision; otherwise, yields will drop and costs will rise.
2) Which Industries Have Higher Requirements for Encoders? Why?
Any closed‑loop equipment containing moving parts requires encoders, but high‑end industries such as semiconductors, display panels, medical devices, and electronics manufacturing have particularly stringent requirements, because their processes involve micron‑ or even nanometer‑level displacement control.
3) Trends in Motion Control Development and New Demands on Encoders
With the rapid development of emerging technologies such as artificial intelligence and new energy, market demand for encoders continues to rise. In particular, driven by AI, the surging demand for high‑end chips has directly boosted encoder usage as semiconductor capacity expands.
Looking ahead, encoder technology is also evolving to meet increasingly demanding application scenarios:
l More miniaturized and lightweight read‑head designs to fit compact spaces
l Stronger customization capabilities to meet specific needs of high‑end applications
l Higher response speeds to match the pace of high‑speed motion control
l Broader system compatibility for easier integration and deployment
l Higher safety and stability to ensure zero‑failure in critical tasks
Position control is not just a "parameter" of a piece of equipment—it is the foundational lifeblood. It determines how precise a component the equipment can machine, how high a yield it can maintain, and how long it can operate safely.
And the encoder is the "industrial eye" within this lifeblood—it is responsible for "seeing" the position, giving the control system the basis for correction. The visual acuity of this "eye" directly caps the upper limit of position control for the entire machine.
The 2026 S‑FACTORY Smart Factory and Automation Technology Exhibition is deeply rooted in the entire smart manufacturing industry chain, bringing together automation companies such as HIWIN, Flexiv, IKO, MOSIONX, KONECRANES, WORLD WIDE GROUP, and MEAN WELL. From October 27‑29 at the Shenzhen World Exhibition & Convention Center, we sincerely invite you to visit the show!
Source: Renishaw