scholarly journals Hydraulic Pressure-Flow Rate Control of a Pallet Handling Robot for an Autonomous Freight Delivery Vehicle

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1370
Author(s):  
Khayyam Masood ◽  
Xavier Dauptain ◽  
Matteo Zoppi ◽  
Rezia Molfino
Keyword(s):  
Hydraulic System ◽  
Hydraulic Pressure ◽  
Processing Unit ◽  
Delivery Vehicle ◽  
Bypass Valve ◽  
Displacement Pump ◽  
Gear Pumps ◽  
Single Sensor ◽  
Robotic Vehicle ◽  
Flow Rate Control

The current paper presents an upgrade of a pre-installed hydraulic system for the operation of a pallet handling robot for a freight delivery vehicle known as FURBOT (freight urban robotic vehicle). The automated forklift installed on FURBOT for loading/unloading of cargo is powered with the help of hydraulics. The previous hydraulic system worked via a classical approach with a fixed displacement pump and a bypass valve, making it work on full power when in use. An alternative design was proposed, simulated and installed on FURBOT; it uses a fixed displacement pump and changes the rotation speed in real time using a pressure sensor. Novelty was attained with the use of gear pumps for said scenario. A control algorithm is implemented in the processing unit for controlling the speed of the motor driving the pump. The main advantage of this approach is better use of energy for the vehicle’s battery. The aim of this research is to control both the speed and maximum force exerted by the actuators with the help of a single sensor and an inexpensive pump.

Reinforcement Learning for Active Noise Control in a Hydraulic System

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Eric R. Anderson ◽  
Brian L. Steward
Keyword(s):  
Reinforcement Learning ◽  
Hydraulic System ◽  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Operating Point ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Active Noise ◽  
Pressure Ripple

Abstract Hydraulic pressure ripple in a pump, as a result of converting rotational power to fluid power, continues to be a problem faced when developing hydraulic systems due to the resulting noise generated. In this paper, we present simulation results from leveraging an actor-critic reinforcement learning method as the control method for active noise control in a hydraulic system. The results demonstrate greater than 96%, 81%, and 61% pressure ripple reduction for the first, second, and third harmonics, respectively, in a single operating point test, along with the advantage of feed forward like control for high bandwidth response during dynamic changes in the operating point. It also demonstrates the disadvantage of long convergence times while the controller is effectively learning the optimal control policy. Additionally, this work demonstrates the ancillary benefit of the elimination of the injection of white noise for the purpose of system identification in the current state of the art.

Design and Research of Hydraulic Station of Hydraulic Tire Curing Press

2012 ◽  
Vol 507 ◽  
pp. 172-175
Author(s):  
Rong Li
Keyword(s):  
Flow Rate ◽  
Hydraulic System ◽  
Switching Time ◽  
Piston Pump ◽  
Hydraulic Pressure ◽  
Pressure Relief ◽  
Hydraulic Station

Analyzes the change of hydraulic pressure and flow rate during the opening/closing and curing processes in the hydraulic system of hydraulic tire curing machine and proposes a new design of the hydraulic station. By using three groups of motors-variable piston pump to work independently, the new hydraulic station can reduce machine downtime. Through using accumulator to keep pressure and delaying switching time of the valve to gradually release pressure, the new hydraulic station solves the problem of the severe impact caused by pressure relief and improve the safety and relia-bility.

STEAM: A Mobile Hydraulic System With Engine Integration

2013 ◽  
Author(s):  
Milos Vukovic ◽  
Sebastian Sgro ◽  
Hubertus Murrenhoff
Keyword(s):  
Hydraulic System ◽  
High Efficiency ◽  
Combustion Engine ◽  
Low Cost ◽  
Total System ◽  
Hydraulic Systems ◽  
Pressure System ◽  
Operating Modes ◽  
Hydraulic Design ◽  
Displacement Pump

In recent years, research institutions worldwide have developed a number of new mobile hydraulic systems. Despite their improved energy efficiency, these systems have yet to gain market acceptance due to their related increase in component costs and decrease in robustness. At the Institute for Fluid Power Drives and Controls in Aachen, a new system for mobile machines, named STEAM (Steigerung der Energieeffizienz in der Arbeitshydraulik mobiler Arbeitsmaschinen), is being developed using inexpensive off-the-shelf components. The aim is to improve the total system efficiency by considering all the subsystems in the machine. This is done by integrating the internal combustion engine (ICE) into the hydraulic design process. By using a constant pressure system in combination with a low-cost fixed displacement pump the hydraulic system is designed to ensure the ICE experiences a constantly high load in a region of high efficiency, so-called point operation. To decrease the hydraulic losses incurred when supplying the linear actuators with flow, an additional intermediate pressure rail with independent metering edges is used. This enables various energy efficient discrete operating modes, including energy regeneration and recuperation.

Energy-Saving Optimization for Wheel Loader's Double-Pump Confluence Hydraulic System with Fixed-Displacement Pump

2013 ◽  
Vol 389 ◽  
pp. 618-622 ◽  
Author(s):  
Zhao Jun Tan ◽  
Yao Jin
Keyword(s):  
Field Test ◽  
Hydraulic System ◽  
Test Results ◽  
Proportional Valve ◽  
Load Pressure ◽  
Wheel Loader ◽  
Displacement Pump ◽  
Operation Rule ◽  
Constant Displacement ◽  
Simulation Results

The field test results show that existing double-pump confluence hydraulic system with constant displacement pump of wheel loader could only save some energy while the load pressure is rather high (>15Mpa in the tests). However, the load pressure is usually low, especially when the wheel Loader is working on bulldozing operation or just steering and running. Thus, an optimized double-pump confluence hydraulic system was designed by adding a proportional valve and adjust operation rule, so that the output oil of steering pump flow into tank by the proportional valve while the load pressure is low and the relative position of joystick is not large (<72%), and in this way the throttle losses is reduced. Simulation results indicate that the optimized confluence hydraulic system could save 26.2% throttle losses while the wheel Loader is working on bulldozing operation.

Research Regarding Pressure Compensated Flow Control Valves

2015 ◽  
Vol 809-810 ◽  
pp. 992-997
Author(s):  
Irina Tiţa ◽  
Irina Mardare
Keyword(s):  
Power Systems ◽  
Flow Control ◽  
Hydraulic System ◽  
Block Diagram ◽  
Control Valve ◽  
Operating Conditions ◽  
Flow Control Valve ◽  
Constant Flow ◽  
Working Pressure ◽  
Displacement Pump

In fluid power systems, flow control may be done either with variable displacement pump or using variable orifice. In this paper is considered the second method for flow control. In a hydraulic system, working pressure is frequently variable and therefore the use of the method does not provide constant flow rates in all operating conditions. In order to keep a constant flow, if this is important in a certain case, the flow control must be accomplished using a pressure compensated flow control valve. In this paper are analyzed possible structural diagrams, mathematical model, block diagram and functional diagram for this kind of equipment. The influence of the spring compression is analyzed also. The diagrams proposed in the paper will be used for the study of a hydraulic system designated for applications with strict flow control. It will represent an important research instrument for such cases.

Design and Analysis of Hydraulic Control System for Pipe Storage and Handling System

2011 ◽  
Vol 480-481 ◽  
pp. 1240-1245
Author(s):  
Yu Wang ◽  
Bao Lin Liu ◽  
Yuan Biao Hu
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Hydraulic Pressure ◽  
Hydraulic Control ◽  
Round Trip ◽  
Handling System ◽  
Piston Speed ◽  
Valve Operation ◽  
Hydraulic Control System ◽  
Pipe Joint

This paper research the hydraulic control system of pipe storage and handling system. The pipe storage and handling system (PSHS) is the key parts on rig to handle the drilling pipe and it can improve the efficiency during the drilling works. The hydraulic system of pipe storage and handling system have designed according to automatic round-trip operation in drilling engineering. The mathematical modeling of hydraulic components in PSHS have established and analyzed. The simulation model of hydraulic system of PSHS is also built and simulated to analysis the characteristics of reversal valve operation, Hydraulic pressure adjusting operation, piston speed control and state of accumulator based on the AMESim. The results prove that the operations of pipe storage and handle such as pipe storage, pipe clamping, pipe lifting, pipe transfer and pipe joint can be accomplished drive by hydraulic system. Meanwhile, AMESim have great views to research the geosciences equipment.

scholarly journals Research Status, Critical Technologies, and Development Trends of Hydraulic Pressure Pulsation Attenuator

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yan Wang ◽  
Tongsheng Shen ◽  
Chunsen Tan ◽  
Jian Fu ◽  
Shengrong Guo
Keyword(s):  
Pressure Pulsation ◽  
Design Method ◽  
Development Trend ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Flow Pulsation ◽  
Simulation Design ◽  
Positive Displacement ◽  
Critical Technology ◽  
Displacement Pump

AbstractHydraulic pumps are a positive displacement pump whose working principle causes inherent output flow pulsation. Flow pulsation produces pressure pulsation when encountering liquid resistance. Pressure pulsation spreads in the pipeline and causes vibration, noise, damage, and even pipeline rupture and major safety accidents. With the development of airborne hydraulic systems with high pressure, power, and flow rate, the hazards of vibration and noise caused by pressure pulsation are also amplified, severely restricting the application and development of hydraulic systems. In this review paper, the mechanism, harm, and suppression method of pressure pulsation in hydraulic systems are analyzed. Then, the classification and characteristics of pulsation attenuators according to different working principles are described. Furthermore, the critical technology of simulation design, matching method with airborne piston pumps, and preliminary design method of pulsation attenuators are proposed. Finally, the development trend of pulsation attenuators is prospected. This paper provides a reference for the research and application of pressure pulsation attenuators.

Spring Parameters Design for the New Hydraulic Actuated Quadruped Robot

2014 ◽  
Vol 6 (2) ◽  
Author(s):  
Xianbao Chen ◽  
Feng Gao ◽  
Chenkun Qi ◽  
Xinghua Tian ◽  
Jiaqi Zhang
Keyword(s):  
Hydraulic System ◽  
Stance Phase ◽  
State Of The Art ◽  
Dynamic Performance ◽  
Weight Ratio ◽  
Quadruped Robot ◽  
Hydraulic Pressure ◽  
System Pressure ◽  
Pump Pressure ◽  
Very High

More and more state-of-the-art robots have employed hydraulic actuating systems. It has a high power-to-weight ratio. Robots with these actuators can bear more payloads and achieve highly dynamic performance. However, the energy consumption is also very high and the system is very complicated comparing to the electronic motor actuated robot. A lot of research has been done to save the energy. Among which the application of springs is one of the most commonly used methods. This paper presents another use of the spring to save the energy by reducing the hydraulic system pressure of a newly built robot called the “Baby Elephant.” The configuration of the spring is designed according to the leg mechanism. The spring gives an assist force in the stance phase of the leg and exerts a passive payload in the swing phase. The maximum cylinder force is then reduced so as to bring down the pump pressure. The energy to be saved depends on how much the hydraulic pressure can be reduced. In this paper, the Baby Elephant is briefly introduced, the design of the springs on saving the energy are described. Simulations and experiments are carried out to confirm the effect.

scholarly journals Research on the Nonlinear Characteristic of Flow in the Electro-Hydraulic Servo Pump Control System

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 814
Author(s):  
Tiangui Zhang ◽  
Gexin Chen ◽  
Guishan Yan ◽  
Cheng Zhang ◽  
Yuan Li ◽  
...  
Keyword(s):  
Control System ◽  
Hydraulic System ◽  
Dead Zone ◽  
Servo Motor ◽  
Saturation Zone ◽  
Output Displacement ◽  
Positive Displacement ◽  
System Flow ◽  
Displacement Pump ◽  
Hydraulic Servo

In an electro-hydraulic servo system, the system flow is used as an intermediate variable to control the output displacement/force/speed of the actuator, and it plays the role of a medium for energy transmission and conversion. Therefore, the control of the system flow is the essence of state control for the system actuator. The purpose of this paper is to study the non-linear characteristics of pump control system flow and pave the way for high-performance control of the system. Based on the flow partition idea, the system output flow is divided into the dead zone, load zone, and saturation zone. We establish a mathematical model of the hydraulic system to analyze and study the effect of the nonlinear characteristics of the servo motor and the positive displacement pump on the system flow partition characteristics. We focus on the effects of the positive displacement pump shear flow internal leakage, pressure difference flow internal leakage, oil compression, servo motor rotation friction, and servo motor torque reserve rate on the system flow output, and analyze the partition characteristics of the system flow under different working conditions. We provide a theoretical basis for a high-precision control strategy for a hydraulic system.

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