Hydraulic servo control system, as an important means of industrial control, its design and operation must meet a series of strict control requirements to ensure efficient, stable and safe operation of the system. The following is a detailed description of the control requirements of the hydraulic servo control system, covering a variety of aspects.
First, the system performance requirements
Wide speed range: hydraulic servo system needs to have a wide speed range to meet the speed control needs of different working conditions. Generally speaking, the speed range of the system should be able to cover a wide range from very low speed to high speed to meet the requirements of a variety of complex motion control.
High positioning accuracy: the system should have high-precision positioning capability and be able to accurately position the actuator to a predetermined position. This requires the system to have a small positional error and repetitive positioning error to ensure the accuracy of processing or operation.
Sufficient transmission rigidity and high speed stability: the hydraulic servo system should have high transmission rigidity and speed stability to ensure that the system can still maintain a stable motion state under load changes or external interference. This helps to reduce the vibration and noise of the system and improve the dynamic performance of the system.
Fast response, no overshoot: the system should be able to respond quickly to input commands and reach a stable state within a specified time. At the same time, the system should avoid generating excessive overshooting to minimize the adverse effects on the actuator and the entire system.
Second, the system reliability requirements
Strong overload capacity: hydraulic servo system should have a strong overload capacity to cope with possible instantaneous overload or shock load. Servo drive should usually be able to withstand overload in a few minutes or even half an hour more than 1.5 times without damage, a short period of time can be overloaded 4 to 6 times without damage.
High reliability: the system should be highly reliable and able to operate stably in a variety of harsh environments. This requires the system has a strong temperature, humidity, vibration and other environmental adaptability and anti-interference ability.
Easy to maintain: the system should be designed to be easy to maintain and repair, in order to reduce downtime and maintenance costs. For example, the system should be modular design, easy to replace and repair faulty parts.
Third, the motor requirements
Smooth operation: from the lowest speed to the highest speed, the motor should be able to run smoothly, torque fluctuations should be small. Especially at low speeds, the motor should have no creeping phenomenon to ensure the stability and accuracy of the system.
Large torque: the motor should have large torque to meet the requirements of low-speed large torque. At the same time, the motor should have a large overload capacity to cope with possible instantaneous overload conditions.
Fast response: In order to meet the requirements of fast response, the motor should have a small moment of inertia and large blocking torque, and have the smallest possible time constant and starting voltage.
Frequent start braking ability: the motor should be able to withstand frequent start, brake and reverse operation to meet the needs of the system to frequently change the state of motion.
Fourth, the servo amplifier parameter requirements
Position proportional gain: position proportional gain should be set according to the specific servo system model and load conditions. The larger the setting value, the higher the gain, the greater the stiffness, the smaller the positional hysteresis under the condition of the same frequency command pulse. However, care should be taken to avoid oscillation or overshoot caused by too large a setting value.
Position feed-forward gain: The setting of position feed-forward gain should also be determined according to the system requirements. The larger the setting value, the smaller the position hysteresis, but it may make the system position unstable and cause oscillation. It is usually set to 0 when high response characteristics are not required.
Speed proportional gain and integral time constant: speed proportional gain and integral time constant settings also need to be determined according to the specific servo drive system models and load conditions. In the system does not produce oscillation conditions try to set a larger value to improve the system response speed but need to pay attention to avoid causing oscillation.
Speed feedback filtering factor: speed feedback filtering factor should be set taking into account the balance between the system's response speed and stability. The larger the value of the cutoff frequency the lower the noise generated by the motor is smaller, but may cause the response slower; the smaller the value of the cutoff frequency the higher the speed of the feedback response faster, but may increase the noise.
Fifth. Summary
Hydraulic servo control system control requirements cover a number of aspects of system performance, reliability, motor and servo amplifier parameters. These requirements together constitute the basis for the design and operation of the hydraulic servo control system for the system's efficient, stable and safe operation provides a guarantee. In practice, it is necessary to make reasonable choices and configurations according to the specific conditions and needs to ensure that the system meets the control requirements and achieve optimal performance.