Guide to synchronizing two linear actuators

With the rapid development of science and technology, linear actuators are increasingly used in various industries, and synchronizing two linear actuators has become a key link in improving system performance. Whether in the aerospace field, the flap control system of an aircraft involves the coordinated work of multiple linear actuators. Or in precision medical equipment, the joint control of surgical robots, the synchronization accuracy of two linear actuators is directly related to the accuracy and safety of surgical operations.

This requires us to conduct in-depth research and exploration, from hardware selection to software control, from system integration to on-site debugging, to solve the synchronization problem in an all-round way, to ensure that linear actuators can work stably and efficiently in a variety of complex working conditions, and provide solid technical support for the development of high-end equipment manufacturing industry. The following are some guides to synchronizing two linear actuators, to show you what a linear actuator is, how a linear actuator works and solutions.

1. What is a linear actuator?

A linear actuator is a mechanical device that converts rotary motion (usually from an electric motor) into linear motion, enabling it to push, pull, lift or position an object in a straight line. It is widely used in industrial machinery, robotics, furniture automation and medical devices where controlled linear motion is required.

2. How does a linear actuator work?

The operation of a linear actuator depends on its type, but the basic working principle involves converting rotational energy into linear motion. Here are the common types and their working mechanisms:

Electric linear actuator

Components: electric motor, lead screw or ball screw and sliding nut.

How it works: The motor rotates the screw, and the nut attached to the screw moves along its length; linear motion is produced; direction is changed by reversing the rotation of the motor.

Uses: adjustable desks, home automation, industrial equipment.

Hydraulic linear actuator

Components: cylinder, piston, hydraulic fluid and control valve.

How it works: pressurized hydraulic fluid pushes a piston in a cylinder, and the movement of the piston produces a linear force, with the direction controlled by the fluid flow.

Uses: heavy machinery, construction equipment (such as excavators).

Pneumatic Linear Actuators

Components: Cylinder, piston, compressed air, and valve.

How it works:

Compressed air enters the cylinder, moving the piston linearly; airflow controls change direction and speed.

Uses: Automation, material handling, and robotics.

Mechanical (manual) linear actuators

Components: Lead screw, handwheel, or gear.

How it works: Manually turning a handle or gear rotates a screw; a screw moves a nut or slides linearly.

Uses: Adjustable machine parts, manual controls.

Piezoelectric linear actuators

Components: Piezoelectric crystals and mechanical elements.

How it works: Applying voltage to a piezoelectric material causes it to expand or contract; this microscopic expansion produces precise linear motion.

Uses: Microscopes, medical devices, and nanotechnology.

Key performance factors

Load capacity: The maximum weight that the actuator can move.

Speed: How fast the actuator can extend or retract.

Stroke length: The total distance the actuator can travel.

Duty cycle: The ratio of active operating time to static time.

3. Solution Guide

Synchronous linear actuator solutions ensure smooth, precise and coordinated motion in applications that require multi-axis control. Here are some of the most effective and reliable solutions:

1. Servo motor driven linear actuators

Precision: High closed-loop feedback accuracy.

Synchronization: Multiple actuators can be synchronized using a shared controller.

Applications: Robotics, CNC machinery and automation.

2. Stepper motor linear actuators with encoders

Cost-effective: Lower cost than servos, but with high precision.

Feedback: Encoders help maintain synchronization and avoid step loss.

Applications: 3D printers, conveyor systems and packaging machines.

3. Integrated linear actuators

All-in-one design: Motor, drive and control electronics are built into the actuator.

Simplified wiring: Reduces complexity and improves reliability.

Applications: Medical equipment, laboratory automation and light industrial use.

4. Screw driven linear actuators (ball screws/lead screws)

High load capacity: Ideal for heavy applications.

Smooth motion: Ball screws have low friction and high efficiency.

Applications: Machine tools, presses, and automated assembly lines.

5. Belt-driven linear actuators

Fast motion: High-speed performance and longer travel range.

Synchronization: Multiple actuators can be driven by a shared belt system.

Applications: Material handling, packaging, and pick-and-place systems.

6. PLC-controlled actuation systems

Programmable logic controller (PLC): Provides advanced synchronization through software.

Scalability: Easily integrate multiple actuators into one system.

Applications: Industrial automation and process control.

7. CANopen/EtherCAT communication systems

Real-time synchronization: Industrial communication protocols enable precise coordination.

Flexibility: Supports long-distance multi-axis control.

Applications: Robotics, conveyor systems, and large-scale automation.

8. Master-slave configuration

Direct control: One actuator acts as the master and controls other actuators (slaves) for synchronized motion.

Load sharing: Prevents uneven loads and mechanical stress.

Applications: Lifting systems, adjustable platforms, and theater stage settings.

9. Load sensor feedback integration

Adaptive control: Sensors adjust actuator motion based on real-time load feedback.

Protection: Prevent overload and misalignment.

Applications: Medical beds, ergonomic workstations, and automatic doors.

10. Customized gear synchronization system

Mechanical linkage: Gears or shafts physically connect actuators for perfect synchronization.

Zero drift: No electrical synchronization required.

Applications: Heavy machinery, conveyors, and synchronous lifting systems.

Summary

Linear actuators are essential for tasks that require reliable and repeatable linear motion, providing automation, precision, and versatility for a variety of industries. Choosing the right solution depends on application requirements, such as load capacity, speed, accuracy, and environmental conditions. The above understanding of what is a linear actuator, how a linear actuator works, and solutions is hoped to be helpful to you.

A precision robotic arm is performing high-precision assembly operations, and the movements of its various joints need to be highly coordinated. If the two key linear actuators are out of sync, it is like one fast and one slow when a person's hands are doing fine movements. Not only can the precise assembly task not be completed, but it may also cause failure or even damage to the entire mechanical system. This kind of asynchrony is very common in many application scenarios. For example, in the paper conveying system of a large printing press, if the linear actuators on both sides are not synchronized, the paper will be skewed, wrinkled, and other problems will seriously affect the printing quality.

FAQ:

1. Why do we need to synchronize two linear actuators?

There are mainly the following reasons for synchronizing two linear actuators: First, to improve the accuracy and stability of the system. For example, in precision machining equipment, synchronized actuators can ensure the machining accuracy of the workpiece; second, to ensure the uniform distribution of the load and avoid overload damage to some actuators due to actuator asynchrony; third, to achieve complex coordinated movements, such as multi-joint coordinated movement of robot arms.

2. What are the application scenarios of linear actuator synchronization?

The application scenarios are very wide, including but not limited to: material handling and assembly equipment on industrial automation production lines, such as joint control of robot arms; aircraft rudder control and flap retraction and extension systems in the aerospace field; surgical robot joint drive in medical devices; sample stage movement control in precision measuring equipment, etc.

3. What key equipment or components are needed in synchronous control?

The following key devices or components are usually required: high-precision position sensors, such as grating scales, magnetic scales, etc., for real-time detection of the position of the actuator; high-performance controllers, such as PLCs, motion controllers, etc., for processing feedback signals and issuing control instructions; drivers, for converting controller instructions into actuator drive signals; in addition, reliable communication interfaces are required to achieve data transmission between the controller and the sensor and driver.

4. How to measure synchronization accuracy?

Synchronization accuracy is generally measured by the following indicators: displacement synchronization accuracy, that is, the displacement deviation of the two actuators during movement; speed synchronization accuracy, which refers to the speed difference between the two actuators; acceleration synchronization accuracy, which indicates whether the accelerations of the two actuators are consistent. The maximum value or root mean square value of these parameters is usually used to quantitatively describe the synchronization accuracy. The smaller the value, the higher the synchronization accuracy.

5. What should I do if there is a deviation when two linear actuators are synchronized?

First, you need to check whether the sensor is working normally and eliminate the detection error caused by sensor failure; secondly, check whether the parameter settings of the controller and driver are correct, such as PID parameters, etc.; then check whether the actuator itself has mechanical failures, such as sticking, wear, etc.; if all of the above are normal, you can consider optimizing the control algorithm to improve the system's anti-interference ability and adaptability.