The Application of HPWM in Improving Vehicle Lateral Stability

2014 ◽  
Vol 936 ◽  
pp. 2171-2176
Author(s):  
An Jing Zhang ◽  
Yan Hai Xu ◽  
Xin Lv
Keyword(s):  
High Speed ◽  
Pulse Width Modulation ◽  
Control Unit ◽  
Lateral Stability ◽  
Hydraulic Control ◽  
Output Pressure ◽  
Switching Valve ◽  
High Speed Switching ◽  
Frequency Pulse

The application of the High-frequency pulse width modulation (HPWM) for improving vehicle lateral stability is investigated in the paper. Firstly, a hydraulic control unit (HCU) combined with a high-speed switching valve (HSV) for controlling hydraulic oil pressure by adjusting duty cycle is presented. Then, a typical control strategy is described based on the application of HPWM. Finally, by using a 15dofs vehicle model, a simulation is carried out to investigate the role of HPWM on improving vehicle lateral stability. The results show that HPWM is capable to control the output pressure of HSV accurately and improve vehicle lateral stability effectively.

scholarly journals Study on control performance of pilot high-speed switching valve

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401770890 ◽  
Author(s):  
Shuang Wang ◽  
Bin Zhang ◽  
Qi Zhong ◽  
Huayong Yang
Keyword(s):  
Response Time ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Oil Pollution ◽  
Duty Ratio ◽  
Main Stage ◽  
Switching Valve ◽  
Discrete Flow ◽  
Modulation Control ◽  
High Speed Switching

High-speed switching valves have been widely studied as pilot valves because of their advantages on easy digital control, low power loss, and non-sensitive to oil pollution. However, there are still lots of difficulties and problems between discrete flow and response time. In this article, two high-speed switching valves are used to pilot a three-way main stage valve. By adjusting the duty ratio of pulse width modulation control signals, the main stage can output continuous flow and pressure. The control performances of two pilot stage methods, which are high-speed switching valve and proportional valve, are compared through the theoretical analysis and the dynamic simulation. It is found that three factors directly affect the response time of the main stage, which are the control signal, the operating frequency of high-speed switching valve, and the pressure of the control chamber. The main valve can achieve better performance if optimized parameters are applied.

Hydraulic Control of a Buck Converter

2021 ◽  
Author(s):  
Rudolf Scheidl
Keyword(s):  
Buck Converter ◽  
Hydraulic Control ◽  
Simple Analytical Model ◽  
Operating Characteristics ◽  
Response Dynamics ◽  
Output Pressure ◽  
Operation Conditions ◽  
Basic Operating ◽  
Periodic Switching

Abstract This paper investigates a concept for the pure hydraulic control of a buck converter using a hydraulically piloted 2-2 way on-off valve. The pilot system is controlled by the desired output pressure of the buck converter in form of a pressure signal and the RC filtered feedback of the actual pressure. These pressures act via small plunger cylinders in opposite direction on the on-off valve. An additional pilot cylinder features a jumping active hydraulic area for a robust feedback. The valve performs close to rectangular oscillations, the frequency of which is mainly determined by the characteristic time of the RC filter. The concept is studied by a simple analytical model to obtain its basic operating characteristics and by a detailed numerical model to analyze the role of parasitic effects on system performance. The paper shows that this concept works and can robustly follow the commanded output pressure. The converter has a moderate response dynamics; in certain operation conditions it shows an aperiodic behavior by alternating between phases of periodic switching and pause.

The Control System Design of AC Servo PMSM Based on an EMCU

2013 ◽  
Vol 380-384 ◽  
pp. 309-312
Author(s):  
Xue Wen Wang ◽  
Zhou Hu Deng ◽  
Xiao Yun ◽  
Long Zhang ◽  
Yuan Zhang
Keyword(s):  
Control System ◽  
Vector Control ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Permanent Magnet Synchronous Motor ◽  
Control Process ◽  
Control Unit ◽  
Vector Model ◽  
Rotating Speed

The mathematical vector model of a permanent magnet synchronous motor (PMSM) has first been discussed in this paper, and a servo control system based on Space Vector Pulse Width Modulation (SVPWM) has been designed, in which a enhanced Microprogrammed Control Unit (EMCU) is combined with drive chips and the relevant control software to achieve the precise control of PMSM. In order to control the position, speed and current of the PMSM, six SVPWM signals are generated with the motor vector control method, and the vector control strategy with three closed loops is projected. According to the control principle, the circuits of the hardware modules are designed and built, and the program of the control process is compiled and downloaded the EMCU, and then the human-computer interaction interface of the system is implemented by LabVIEW. The results of the test show that the control system designed can control the rotating speed and the high-speed pendulum operation of PMSM precisely.

PWM Power Supply Using SiC RESURF JFETs with High Speed Switching

2013 ◽  
Vol 740-742 ◽  
pp. 1056-1059
Author(s):  
Satoshi Hatsukawa ◽  
Takashi Tsuno ◽  
Kazuhiro Fujikawa ◽  
Nobuo Shiga ◽  
Tuya Wuren ◽  
...  
Keyword(s):  
Pulse Width ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Sine Wave ◽  
Pulse Width Modulated ◽  
Fast Switching ◽  
Input Waveform ◽  
Switching Characteristics ◽  
High Speed Switching ◽  
Reduced Surface

400V/2.5A 4H-SiC JFETs, having a reduced surface field (RESURF) structure have been fabricated. Measurements on the on-resistance, blocking, and switching characteristics were carried out. It was confirmed that the JFET has fast switching characteristics. A demonstration of a Pulse Width Modulation (PWM) decoder using JFETs was carried out. The input waveform, which is pulse width modulated 20.5MHz at 4.1MHz sine wave, as able to be decoded at 4.1MHz sine wave.

scholarly journals Influence of eddy current on the dynamics of high speed switching valve.

1993 ◽  
Vol 24 (4) ◽  
pp. 504-510 ◽  
Author(s):  
Yasukazu SATO ◽  
Shojiro SATO ◽  
Hirohisa TANAKA ◽  
Yasuyuki YANAI
Keyword(s):  
Eddy Current ◽  
High Speed ◽  
Switching Valve ◽  
High Speed Switching

Modeling and Validation of a High Speed Rotary PWM On/Off Valve

2009 ◽  
Author(s):  
Haink C. Tu ◽  
Michael B. Rannow ◽  
Meng Wang ◽  
Perry Y. Li ◽  
Thomas R. Chase
Keyword(s):  
High Speed ◽  
Pulse Width Modulation ◽  
Hydraulic Systems ◽  
Rotary Valve ◽  
Flow Area ◽  
Output Pressure ◽  
Critical Technology ◽  
Variable Displacement ◽  
Pressure Ripple ◽  
Actuation Power

Efficient high-speed on/off valves are a critical technology for enabling digital control of hydraulic systems via pulse-width-modulation (PWM). High-speed valves, when used in virtually variable displacement pumps (VVDP), increase system bandwidth and reduce output pressure ripple by enabling higher PWM frequencies. Our approach to achieving high speed and large flow area with low actuation power is a unidirectional rotary valve designed specifically for PWM. In comparison to conventional valves, the rotary valve reduces valve actuation power from a cubic dependence on PWM frequency to a square dependence by eliminating motion reversals during transition. This paper presents experimental data that validates the rotary valve concept, valve design equations, and dynamic model of a rotary valve based VVDP. Our unoptimized prototype exhibits 65% efficiency at 50% displacement and 15Hz PWM frequency while the validated model projects that an optimized valve is capable of achieving 85% efficiency at 15Hz and 73% at 75Hz.

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