Qipeng Li

Novel bidirectional linear actuator for electrohydraulic valves

This paper presents a permanent-magnet actuator with bidirectional and high levels of linear force over short strokes. The actuator can be used in electrohydraulic valves. Its static and dynamic performances were analyzed by using two-dimensional finite-element magnetic field solutions that take into account the nonlinearity of the material. The measured and simulated results are highly consistent. Experimental results show that the prototype actuator can produce a force of /spl plusmn/60 N, its nonlinearity is less than 0.5%, and the hysteresis is less than 2% within a stroke of /spl plusmn/1 mm. The actuators frequency response (-3 dB) can reach 150 Hz.

Novel Bidirectional Rotary Proportional Actuator for Electrohydraulic Rotary Valves

This paper presents a bidirectional rotary actuator for electrohydraulic rotary valves using permanent-magnet rotor with output torques and angular displacements proportional to the excitation currents. Finite-element analysis provides the static characteristics of the actuator and the analysis is coupled to a nonlinear time domain simulation to determine the dynamic performance. The measured and simulated results agree well and show that the actuator can produce torques up to plusmn0.65 Nm, linear angular displacements of plusmn8deg with hysteresis less than 4%, and frequency bandwidth (-3 dB) about 190 Hz.

Novel High-Speed Electromagnetic Actuator With Permanent-Magnet Shielding for High-Pressure Applications

We present a novel moving-iron, high-pressure, high-speed electromagnetic actuator that utilizes permanent-magnet (PM) shielding for increasing air-gap flux. We analyze its static and dynamic characteristics by using the finite-element method, taking into account the nonlinear characteristics and the eddy-current loss of the magnetic material. The experimental and simulated results agree well and show that the actuator has a displacement of 0.6 mm, closing time of 2.24 ms, and opening time of 7.78 ms without latching force.

Novel high-response electromagnetic actuator for electronic engraving system

We describe a new moving-iron electromagnetic actuator that utilizes cantilever-beam-type springs, /spl pi/ type armature, full-bridge magnetic circuits, and a single driving coil. The actuator is suitable for electromechanical converters with high response and minor displacement for use in electronic engraving systems. We analyzed its static and dynamic characteristics by using a three-dimensional finite-element method. We used a simple and practical measuring method based on light reflection to detect the actuators real hysteresis loop and amplitude frequency response characteristics. The results show that the actuator has a displacement of /spl plusmn/65 /spl mu/m, hysteresis of less than 5.5%, and amplitude cutoff frequency of 3.1 kHz. We tested the actuator on a real engraving system and confirmed its characteristics by the engraving results.

A novel eddy current angle sensor for electrohydraulic rotary valves

We present an eddy current angle sensor for high-pressure electrohydraulic rotary valves. An oblique ring-shaped sensing coil and a symmetric semi-cylindrical rotor are utilized, making the coil impedance and the output voltage proportional to the angular displacements. Analysis based on an electrical equivalent circuit and the finite-element method is provided, and good agreement is obtained between the simulated and measured results. Extensive experiments have shown that the sensor has a linear working range of about 30° with nonlinearity 0.8% and temperature drift less than 1% over 30 °C–90 °C.

High-Response Electromagnetic Actuator With Twisting Axis for Gravure Systems

We present a new moving-iron electromagnetic actuator utilizing a single driving coil, a twisting axis as high-stiffness spring, and laminated permalloy material. We analyze its static and dynamic characteristics using the finite-element method, and then we present measurements of the real hysteresis loop and frequency response of the actuator based on a flash charge-coupled device (CCD) laser microangular displacement sensor. The results show that the actuator has angular displacement of plusmn0.0064 rad, low hysteresis of less than 5%, and amplitude frequency response (-3 dB) of 4.3 kHz. We have tested the actuator successfully in a gravure system.

The error analysis of the tack measurement for non-Newtonian fluid based on the inkometer

This paper presents the error analysis of the tack measurement for non-Newtonian fluid based on the inkometer. Offset inks are taken as the analysis object, and a force analysis model is established to analyze the remarkable influence of the surplus force on the sensitivity and the precision of the tack measurement of offset inks. Experimental and theoretical analyses are carried out and are in good agreement. The results show that the measuring angle and the resisting torque of the roll bearing in the measurement roller have primary influences on the surplus force. Corresponding approaches to improve the sensitivity and the precision of the tack measurement are proposed.