Nowadays, many machinery manufacturers are choosing to […]
Nowadays, many machinery manufacturers are choosing to use injection molding machine manipulators as the main production method, but the use of automated manipulators in production can improve product production efficiency and product quality, and reduce the production cost of products. Whether the robot manipulator can work accurately is actually a three-dimensional positioning problem, which is a combination of several linear and angular positioning. In many simpler cases, a single quantity may be dominant. The factors that affect the positioning error of a single line or angle are as follows:
1. Positioning method-different positioning methods have different influencing factors. For example, when the mechanical stop is positioned, the positioning accuracy is related to the stiffness of the stop and the speed when the stop is touched.
2. Positioning speed-positioning speed has a great influence on positioning accuracy. This is because when the positioning speed is different, the energy of the moving parts that must be dissipated is different. Generally, in order to reduce the positioning error, the positioning speed should be reasonably controlled, such as improving the buffering performance and buffering efficiency of the buffering device, and controlling the drive system to decelerate the moving parts in a timely manner.
3. Accuracy-The manufacturing accuracy and installation speed adjustment accuracy of the manipulator have a direct impact on the positioning accuracy.
4. Rigidity-When the structural rigidity and contact rigidity of the manipulator itself are low, the positioning accuracy is generally low due to easy vibration.
5. The weight of the moving part-the weight of the moving part includes the weight of the manipulator itself and the weight of the object being grabbed. Changes in the weight of moving parts have a greater impact on positioning accuracy. Generally, when the weight of the moving parts increases, the positioning accuracy decreases. Therefore, it is necessary to not only reduce the weight of the moving parts itself, but also consider the influence of changes in the grasping weight during work.
6. Drive source-pressure fluctuations of hydraulic pressure and air pressure, and fluctuations of voltage, oil temperature, and air temperature will affect the repeat positioning accuracy of the manipulator. Therefore, take necessary measures to stabilize and adjust the oil temperature. For example, use accumulator to stabilize oil pressure, use heater or cooler to control oil temperature, and use temperature and pressure compensation flow control valve to control at low speed.
7. Control system-the position control accuracy of switch control, electro-hydraulic proportional control and servo control is different. This is not only because the accuracy and sensitivity of various control elements are different, but also related to the presence or absence of a position feedback device.