Due to factors such as machining errors and installation errors, there is a deviation between the ideal structural parameters (hinge position, rod length, etc.) of the parallel mechanism and the actual structural parameters, resulting in inaccurate kinematic models of the parallel mechanism and affecting the accuracy of the parallel robot.

There are currently two main methods to improve the accuracy of parallel mechanisms:

The first approach is to directly improve the manufacturing and installation accuracy of each component of the parallel structure, but this will significantly increase processing costs and also require a high level of ability from assembly personnel.

The second method is to calibrate the parameters of the assembled parallel mechanism, usually through kinematic calibration. This method is currently widely adopted due to its low cost and high efficiency.

Kinematic calibration is the process of using advanced measurement methods and model-based parameter identification methods to identify the accurate parameters of the robot model. By using additional control algorithms or modifying the original control algorithm to compensate for robot errors, the absolute accuracy of the robot is improved.

According to customer needs and market conditions, high-precision parallel mechanisms are the future trend.

The following is the calibration process carried out by Zhengyu Technology for customized platforms for customers:

Calibration preparation: Use a laser tracker for calibration work and use an ADM measurement system for error measurement.

Result comparison:

Before calibration: Repetitive positioning accuracy: ± 0.005mm, positioning accuracy: 0.05mm.

After calibration: Repetitive positioning accuracy: ± 0.005mm, positioning accuracy: 0.01mm.

From the calibration results, it can be seen that the kinematic accuracy of parallel mechanisms has been significantly improved, and forward domain technology is further applied in the field of high-precision parallel mechanisms.