The concurrent implementation of high velocity control performance and high energy efficiency for hydraulic injection moulding machines

Proceedings of the JFPS International Symposium on Fluid Power

Chen

2008

In the hydraulic servo control applications, hydraulic valve-controlled systems, which have a problem of low energy efficiency, are used mostly because of the high response characteristics. Hydraulic pump-controlled servo systems have high energy-efficiency. However, the conventional pump-controlled systems, which are altered by displacement via variable displacement pumps, have lower response. This paper aims to investigate the servo performance of the high response and high energy efficiency electro-hydraulic pump-controlled system driven by a variable rotational speed AC servo motor in comparison with the conventional pump-controlled systems which are altered by displacement via variable displacement pumps. For that, the control strategy, adaptive fuzzy sliding-mode controller (AFSMC) is introduced. The AFSMC can not only simplify the fuzzy rule base but also estimate the equivalent control force and online self-tune the rule base through the adaptive strategy. The developed high response variable rotational speed electro-hydraulic pump-controlled system controlled by AFSMC and the conventional variable displacement pump-controlled system (VDPCS) are implemented and verified experimentally for velocity control with various velocity targets and external loading conditions. Furthermore, the energy efficiencies of different experiments are analyzed and compared precisely by the power quality recorder used to measure the electrical power consumed by the AC servo motor.

Section: Introductionmentioning

confidence: 99%

A Comparison of an Ac-Servo Motor Driving Variable Rotational Speed and a Variable Displacement Pump-Controlled Systems for Velocity Control

Proceedings of the JFPS International Symposium on Fluid Power

Chen

2008

“…The velocity control, pressure control and phase switching control of the HIMM have been discussed and published in general terms [1][2][3][4][5]. In the conventional HIMM, the clamping force was controlled indirectly by means of the pressure control of the clamping cylinder via a servo valve.…”

Section: Introductionmentioning

confidence: 99%

“…For that reason, the energy-saving control, such as load-sensing control (LSC) and constant supply pressure control (CSPC), is introduced to improve the energy efficiency in the HVCCS. The LSC enables the supply pressure to be adjusted according to the load-sensing pressure of the hydraulic actuator thereby achieving the energy-saving effects by keeping a constant difference between the supply pressure and the load-sensing pressure [3,6,7]. Moreover, the integrated control of velocity-force control and energy-saving control in HVCSS is more complicated than the force control or velocity control alone, therefore it is indispensable to develop an appropriate controller to provide the excellent velocity-force control response as well as high energy efficiency for the HIMM.…”

Section: Introductionmentioning

confidence: 99%

Concurrent Control of Velocity-Force Control and Energy-Saving Control in Hydraulic Value-Controlled Cylinder Systems

Proceedings of the JFPS International Symposium on Fluid Power

Yang²,

Chen³

et al. 2005

High servo control response and high energy-efficiency are requested in hydraulic servo systems of current hydraulic machines. This investigation concurrently implements energy-saving control and velocity-force control for simultaneously realizing high velocity-force control response and high energy-efficiency for hydraulic valve-controlled cylinder systems. The velocity-force control of the hydraulic cylinder, including 1st stage of velocity control and 2nd stage of force control, can be applied in hydraulic machines, i.e. injection moulding machines. The energy-saving control implemented here contains load-sensing control, constant supply pressure control and constant supply power control. The concurrent control of energy-saving control and velocity-force control of the hydraulic valve-controlled cylinder system becomes a two-input and two-output control problem. For that, an intelligent control strategies using fuzzy sliding mode control is developed. The experimental comparisons of the four different systems, including velocity-force control with load-sensing control, velocity-force control with constant supply pressure control, velocity-force control with constant supply power control and velocity-force control without energy-saving control, are implemented for the same velocity-force profile. The minimum consumed powers in each system are compared. The feasibility of the concurrent control of energy-saving control and velocity-force control is verified experimentally.KEY WORDS

“…However, the enhancement of energy efficiency in HIMMs has become a very important and decisive factor in the competition with EIMMs [1]. The study of the integration of velocity control (VC) and energy-saving control (ESC) in HIMMs was published first by Chiang, et al [3]. Chiang et al [6] discussed the parallel control of path control and ESC in hydraulic valve-controlled cylinder systems (HVCCS).…”

mentioning

confidence: 99%

“…For that reason, ESC, such as load-sensing control (LSC) and constant supply pressure control (CSPC), is introduced to improve the energy efficiency in the HVCCS. LSC enables the supply pressure to be adjusted according to the load-sensing pressure of the hydraulic actuator, thereby achieving the energy-saving effects by keeping a constant difference between the supply pressure and the load-sensing pressure [3,6,7]. Due to the characteristics of FC in HVCCS, the traditional control strategy, i.e.…”

mentioning

confidence: 99%

Integrated control of clamping force and energy-saving in hydraulic injection moulding machines using decoupling fuzzy sliding-mode control

Int J Adv Manuf Technol

Yeh

Yang

et al. 2005

The objective of this research is to implement a novel parallel control of clamping force and energy-saving in hydraulic injection moulding machines (HIMMs) in order to simultaneously achieve accurate force control response and high energy efficiency. In order to verify the feasibility of the integrated control system and compare energy-saving effects, the clamping force control of HIMMs can be integrated with two different energy-saving control systems or integrated with a conventional hydraulic system without energy-saving control. The overall control system is a coupled two-input two-output system. Therefore, a decoupling fuzzy sliding-mode control (DFSMC) strategy, which can reduce the fuzzy rule numbers and counteract the coupling effects, is developed for the integrated control of HIMMs. The experimental results show the outstanding performance of the parallel control in HIMMs with DFSMC.