Model Predictive Control and Discrete Analysis of Partial Stroke Operated Digital Displacement Unit

Pedersen, Niels Henrik; Johansen, Per Michael; Andersen, Torben Ole

doi:10.1109/gfps.2018.8472366

Cited by 4 publications

(4 citation statements)

References 11 publications

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“…Therefore, model predictive control (MPC) is considered to have a high potential for control of a partial stroke operated DDM. MPC does however require a discrete model representation of the system dynamics Sniegucki et al (2013); Pedersen et al (2018c). For partial stroke operation, only a part of the full stroke is used, which introduces additional complications seen from a partial stroke discrete approximation shown in Fig.…”

Section: Partial Stroke Strategymentioning

confidence: 99%

Challenges with Respect to Control of Digital Displacement Hydraulic Units

Pedersen

Johansen²,

Andersen³

2018

MIC

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This paper investigates the many complications arising when controlling a digital displacement hydraulic machine with non-smooth dynamical behavior. The digital hydraulic machine has a modular construction with numerous independently controlled pressure chambers. For proper control of dynamical systems, a model representation of the systems fundamental dynamics is required for transient analysis and controller design. Since the input is binary (active or inactive) and it may only be updated discretely, the machine comprises both continuous and discrete dynamics and therefore belongs to the class of hybrid dynamical systems. The study shows that the dynamical system behavior and control complexity are greatly dependent on the configuration of the machine, the operation strategy, and in which application it is used. Although the system has non-smooth dynamics, the findings show that simple continuous and discrete approximations may be applicable for control development in certain situations, whereas more advanced hybrid control theory is necessary to cover a broader range of situations.

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Section: Partial Stroke Strategymentioning

confidence: 99%

Challenges with Respect to Control of Digital Displacement Hydraulic Units

Pedersen

Johansen²,

Andersen³

2018

MIC

Self Cite

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“…In the matter of flow distribution characteristics and control strategies for a digital pump, Pan et al simulated the flow distribution characteristics of the FDV groups under clockwise and counterclockwise strokes of the motor, the steering variation process of the motor, and the effect of the switching valve frequency on the hydraulic motor [12]. Pederson et al proposed continuous, discrete, hybrid dynamic approximate methods for digital pumps/motors, but there are still many challenges to be solved [13][14][15][16]. Based on the three pistons pump/motor, Breidi proposed a prediction for valve response delay time and mode switching algorithm using pressure fluctuations in high and low pressure lines, realizing an automatic selection of the most efficient control strategy among different displacement control strategies [17,18].…”

Section: Introductionmentioning

confidence: 99%

An Adaptive Control Method for the Distribution Valve of a Digital Pump

et al. 2023

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Perfect flow distribution is extremely important and essential for digital pumps. However, the fluctuation of motor speed and the change of valve dynamic characteristics cause the flow distribution flaw, which generates the backflow of the oil in the piston chamber and the decrease in pump volumetric efficiency. Based on the three-dimensional and mathematical modeling of the digital pump, the perfect distribution state of the digital pump is analyzed. Then, the adverse effects of the variations in motor speed and valve dynamic characteristics on the flow distribution of the digital pump were simulated and investigated by the software AMESim. To overcome the aforementioned problems, we proposed an adaptive control method for the flow distribution valve of a digital pump, which was realized by adopting the axis rotation angle and the pressure difference between the inlet and outlet of the flow distribution valve. The results show that the control signal of the flow distribution valve can be regulated automatically along with the motor speed and the valve dynamic characteristics, achieving the ideal flow distribution of the digital pump designed in this paper. The study can be used as a reference for the optimal design and prototype manufacturing of the digital pump.

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“…Both continuous, discrete, and hybrid dynamical system approximations have been investigated. The continuous and discrete approximations are sufficient to describe the fundamental dynamics if the number of cylinders and displacement fraction is sufficiently high [5][6][7][8][9][10][11]. In the case of applying linear control theory on a variable speed unit, the shaft speed of the machine should not be lower than the speed used during linearization of the system.…”

Section: Introductionmentioning

confidence: 99%

Dynamic Response of a Digital Displacement Motor Operating with Various Displacement Strategies

et al. 2019

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Digital displacement technology has the potential of revolutionizing the performance of hydraulic piston pumps and motors. Instead of connecting each cylinder chamber to high and low pressure in conjunction with the shaft position, two electrically-controlled on/off valves are connected to each chamber. This allows for individual cylinder chamber control. Variable displacement can be achieved by using different displacement strategies, like for example the full stroke, partial stroke, or sequential partial stroke displacement strategy. Each displacement strategy has its transient and steady-state characteristics. This paper provides a detailed simulation analysis of the transient and steady-state response of a digital displacement motor running with various displacement strategies. The non-linear digital displacement motor model is verified by experimental work on a radial piston motor.

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Model Predictive Control and Discrete Analysis of Partial Stroke Operated Digital Displacement Unit

Cited by 4 publications

References 11 publications

Challenges with Respect to Control of Digital Displacement Hydraulic Units

Challenges with Respect to Control of Digital Displacement Hydraulic Units

An Adaptive Control Method for the Distribution Valve of a Digital Pump

Dynamic Response of a Digital Displacement Motor Operating with Various Displacement Strategies

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