Analysis of Electromagnetic Nonlinearities in Stage Control of a Stepper Motor and Spool Valve

Author(s):  
R. Burton ◽  
J. Ruan ◽  
P. Ukrainetz ◽  
D. Bitner

In digital valves, stepper motors are often used as the electro-to-mechanical interface. To sustain both high speed of response and good quantitative accuracy, a special algorithm has been designed to control the stepper motor to produce a continuous displacement. Unlike conventional proportional magnets or torque motors, the input current to the stepper motor is cyclic (stage control) which has been shown to reduce magnetic saturation and hysteresis. In this paper a special mathematical formulation is developed to simulate magnetic saturation and hysteresis which can be applied to a generic situation. The mathematical formulation derived is one in which hysteresis and saturation parameters are established; an error rate of both saturation and hysteresis is defined from this. Since the error rates are easily determined experimentally or through manufacturers’ specifications, the parameters can be found from these mathematical formulations. The parameters can then be used to predict the hysteresis and saturation characteristics. Special experiments are designed to obtain the input-output characteristics of a stepper motor/valve system under single and multi-stage control. The model follows the experimental results reasonably well and can be used with confidence to model any system with hysteresis and saturation. The model also predicts very well the effects of using stage control in reducing hysteresis and saturation in a practical valve.

2003 ◽  
Vol 125 (3) ◽  
pp. 405-412 ◽  
Author(s):  
Rich Burton ◽  
Jian Ruan ◽  
Paul Ukrainetz

In digital valves, stepper motors are often used as the electro-to-mechanical interface. To sustain both high speed of response and good quantitative accuracy, a special algorithm has been designed to control the stepper motor to produce a continuous rotary displacement. Since in this algorithm the current to each coil is cyclic as the rotor tooth advances, several cycles can be used to achieve the desired angular displacement of the motor. This process can result in a reduction or “scaling down” of magnetic nonlinearities such as hysteresis and saturation. This cyclic algorithm has been defined as “stage control” because the algorithm need only be developed for one stage and then repeated when applied to subsequent stages. Critical to the development and understanding of the algorithm is an accurate model of the electromagnetic saturation and hysteresis which exist between the input current and output torque. In this paper, a special mathematical formulation is developed to simulate magnetic saturation and hysteresis which can be applied to a more generic situation. The mathematical formulation derived is one in which hysteresis and saturation parameters are established; an error rate of both saturation and hysteresis is defined from this. Since the error rates are easily determined experimentally or through manufacturers’ specifications, the parameters can be found from these mathematical formulations. The parameters can then be used to predict the hysteresis and saturation characteristics. Special experiments are designed to obtain the input-output characteristics of a stepper motor/valve system under single and multistage control. The model follows the experimental results reasonably well and can be used with confidence to model any system with hysteresis and saturation. The model also predicts very well the effects of using stage control in reducing hysteresis and saturation in a practical valve.


Author(s):  
D O Carrica ◽  
S A Gonzalez ◽  
M Benedetti

Stepper motor driving through conventional on-line control algorithms fails to produce a high-speed rate. In recent years this has become an issue, especially when applications involve microstepping drives. In this work an analysis of the problem is presented and a new algorithm is proposed that does not have the speed restriction of the conventional ones and does not require hardware timers. The proposed algorithm is first rehearsed by applying it to a stepper motor model, verifying that it allows higher speeds than conventional algorithms. Then a series of experimentations are carried out with a hybrid stepper motor.


2019 ◽  
Vol 27 (4) ◽  
pp. 772-780 ◽  
Author(s):  
Tao Ai ◽  
Aslam M. Mudassar ◽  
Ziqi Cai ◽  
Zhengming Gao
Keyword(s):  

2011 ◽  
Vol 130-134 ◽  
pp. 3954-3957
Author(s):  
Liu Wei

Mitsubishi FX2n series PLC's CPU module comes with high-speed pulse output channels. Using these channels, you can achieve position control of stepper motor. This article describes the use of high-speed pulse output instruction on the stepper motor control to achieve the design points. Contents include: key issues of PLC equipment selection, use of pulse command, and the stepper motor selection and setting.


Machines ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 56 ◽  
Author(s):  
Chiu-Keng Lai ◽  
Jhang-Shan Ciou ◽  
Chia-Che Tsai

Owing to the benefits of programmable and parallel processing of field programmable gate arrays (FPGAs), they have been widely used for the realization of digital controllers and motor drive systems. Furthermore, they can be used to integrate several functions as an embedded system. In this paper, based on Matrix Laboratory (Matlab)/Simulink and the FPGA chip, we design and implement a stepper motor drive. Generally, motion control systems driven by a stepper motor can be in open-loop or closed-loop form, and pulse generators are used to generate a series of pulse commands, according to the desired acceleration/run/deceleration, in order to the drive system to rotate the motor. In this paper, the speed and position are designed in closed-loop control, and a vector control strategy is applied to the obtained rotor angle to regulate the phase current of the stepper motor to achieve the performance of operating it in low, medium, and high speed situations. The results of simulations and practical experiments based on the FPGA implemented control system are given to show the performances for wide range speed control.


Author(s):  
Feng Wang ◽  
Mauro Carnevale ◽  
Luca di Mare ◽  
Simon Gallimore

Computational Fluid Dynamics (CFD) has been widely used for compressor design, yet the prediction of performance and stage matching for multi-stage, high-speed machines remain challenging. This paper presents the authors’ effort to improve the reliability of CFD in multistage compressor simulations. The endwall features (e.g. blade fillet and shape of the platform edge) are meshed with minimal approximations. Turbulence models with linear and non-linear eddy viscosity models are assessed. The non-linear eddy viscosity model predicts a higher production of turbulent kinetic energy in the passages, especially close to the endwall region. This results in a more accurate prediction of the choked mass flow and the shape of total pressure profiles close to the hub. The non-linear viscosity model generally shows an improvement on its linear counterparts based on the comparisons with the rig data. For geometrical details, truncated fillet leads to thicker boundary layer on the fillet and reduced mass flow and efficiency. Shroud cavities are found to be essential to predict the right blockage and the flow details close to the hub. At the part speed the computations without the shroud cavities fail to predict the major flow features in the passage and this leads to inaccurate predictions of massflow and shapes of the compressor characteristic. The paper demonstrates that an accurate representation of the endwall geometry and an effective turbulence model, together with a good quality and sufficiently refined grid result in a credible prediction of compressor matching and performance with steady state mixing planes.


Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5288
Author(s):  
Naveen Shirur ◽  
Christian Birkner ◽  
Roman Henze ◽  
Thomas M. Deserno

Automotive airbags protect occupants from crash forces during severe vehicle collisions. They absorb energy and restrain the occupants by providing a soft cushion effect known as the restraint effect. Modern airbags offer partial restraint effect control by controlling the bag’s vent holes and providing multi-stage deployment. Full restraint effect control is still a challenge because the closed-loop restraint control system needs airbag–occupant contact and interaction feedback. In this work, we have developed novel single and matrix capacitive tactile sensors to measure the occupant’s contact data. They can be integrated with the airbag surface and folded to follow the dynamic airbag shape during the deployment. The sensors are tested under a low-velocity pendulum impact and benchmarked with high-speed test videos. The results reveal that the single sensor can successfully measure occupant–airbag contact time and estimate the area, while the contact position is additionally identified from the matrix sensor.


Sign in / Sign up

Export Citation Format

Share Document