Multi-margin pump valve combined hydraulic system for electro-hydraulic servo six-degree-of-freedom parallel robot

Abstract

The invention discloses a multi-margin pump and valve combined hydraulic system for an electro-hydraulic servo six-degree-of-freedom parallel robot. The multi-margin pump and valve combined hydraulic system comprises a static pressure supporting servo cylinder, a valve control module and a pump control module. The valve control module is a redundant valve group formed by connecting a servo valve, a proportional valve and an electromagnetic directional valve in parallel, the valve control module is designed into a multi-valve parallel scheme capable of realizing non-interference switching of oil ways, and the working stability and reliability of a servo cylinder are ensured; the pump control module is composed of a variable pump and a motor, and it is guaranteed that the system can still achieve high-precision motion control under the condition that a servo valve and a proportional valve fail. The valve control module is combined with the pump control module to ensure that the static pressure supporting servo cylinder always keeps a high-precision motion control state to be matched with an independently-controlled switch valve to achieve interference-free switching of oil ways, in addition, energy accumulators are arranged at multiple positions, pipeline pressure fluctuation is stabilized, the flow peak value of a pump station is compensated, the working stability of the system is effectively improved, and the service life of the system is prolonged. And the energy utilization rate is improved.

Description

technical field [0001] The invention belongs to the field of hydraulic systems, in particular to a multi-margin pump-valve combined hydraulic system for an electro-hydraulic servo six-degree-of-freedom parallel robot. Background technique [0002] The six-degree-of-freedom parallel robot refers to a closed-loop robot in which the fixed platform and the moving platform of the robot are connected by multiple motion branches, have six degrees of freedom, and are driven in parallel. Compared with serial robots, the six-degree-of-freedom parallel robot has the advantages of high carrying capacity, high stiffness, stable structure, and high end flexibility. Carry out performance tests in any pose state. At present, this type of robot has been widely used in the automatic fuel filling device of launch vehicle, the docking of aerospace product modules, road simulators, etc. It is of great significance to my country's aerospace applications, weapons research and other fields. Consi...

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Problems solved by technology

The existing parallel robot electro-hydraulic servo system can achieve high-efficiency and high-precision docking under normal operating conditions, but because it does not fully consider the margin design and joint control of pumps and valves, there are mainly the following hidden dangers: 1) The servo motor The hydraulic system is extremely sensitive to oil. Once the servo valve spool sticks or fails during position tracking, if the problem occurs when the spool is closed, it is only necessary to switch to the reserve proportional valve to repair the servo cylinder. control

However, if the problem occurs when the spool is open, the servo valve circuit cannot be cut off in time. At this time, when switching to the proportional valve, the two valves will jointly control the single servo cylinder, causing the robot to lose control; 2) Similarly, when the proportional valve appears When it

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