Current Issue : April - June Volume : 2019 Issue Number : 2 Articles : 5 Articles
In this paper, we deal with a simple embedded electronic system for an industrial\npneumaticâ??hydraulic system, based on a low-cost programmable logic controller (PLC) and industrial\nelectronic parts with 24 V logic. The developed system is a hydraulic pulse system and generates a\nseries of high-pressure hydraulic pulses with up to a max. 200 bar output pressure level and with\nup to a max. 2 Hz output hydraulic pulses frequency. In this paper we are describing requirements,\nthe concept of the embedded control system in a diagram, security features and its industrial\nnetwork connectivity (CAN bus, MODBUS). In description of the software solution we describe the\nimplementation of the program threads approach in this low-cost PLC. The PLC programming with\nthreads generate two layers of services-physical and application layer, and as a result, the threads\ncreate the main control state machine. In conclusion, we describe the calibration method of the system\nand the calibration curves. For further study we offer readers the full programming code written in\nsequential function charts to be used as PLC language. The cost of the described industrial networked\ncontrol system with industry standard optoelectronic insulated interfaces and certified industrial\nsafety relay does not exceed 1000 Euros....
Making full use of front road grade information to achieve the best fuel efficiency is\nimportant for intelligent vehicles. Normal theoretical studies pay too much attention to engine\ncontinuous feedback control. The theoretical foundation of switching between traction and brake\ncontrol has been ignored. In mountainous terrain, both the engine and road slopes are energy sources.\nSwitching between traction and brake control is the key point. This research focuses on broadening\nthe normal control range. The comprehensive objective function that contains traction and brake\ncontrol is built, and then the analytical switching control law is derived based on Pontryaginâ??s\nmaximum principle (PMP). Analytical switching control laws express the mechanism of switching\nbetween traction and brake control for economic cruise control (ECC). Simulation results show that\nthe model can solve the switch time and the entire speed profile precisely. Brake control is very\nimportant in downhill situations. The parameters in the objective function influence not only the\nswitch time but also the switch process. This research offers a theoretical foundation for ECC with\nroad slopes and can make onboard control more precise and efficient....
This paper introduces a novel control strategy into the insulation space for liquid natural gas\ncarriers. The control strategy proposed can improve the effects of control for differential pressure and\nreduce the energy consumption of nitrogen. The method combines a nonlinear feedback technique\nwith a closed-loop gain shaping algorithm (CGSA). It is designed for the pressure control system\nwhich is vital for liquid natural gas carriers (LNGCs) in marine transportation. The control error\nis modulated using nonlinear function. The deviation signal is replaced with a nonlinear feedback\nsignal. Comparison experiments are conducted under different conditions to prove the effectiveness\nof this strategy. This paper compares three control strategies: a control strategy with nonlinear\nfeedback based on CGSA, a control strategy without nonlinear feedback based on CGSA, and a\ntwo-degree-of-freedom (DOF) control strategy. The simulation results show that this control strategy\nwith nonlinear feedback performs better than the other two. The average reduction of control input\nis about 38.8%. The effect of pressure control is satisfactory....
In this paper, the problems of event- and self-triggered control are studied for a nonlinear\nbicycle robot model. It has been shown that by applying control techniques based on triggering\nconditions, it is possible to reduce both state-based performance index, as well as the number of triggers,\nin comparison to a standard linear-quadratic control which consumes less energy of the control system\nand decreases the potential mechanical wear of the robot parts. The results presented in this paper open\na new research field for further studies, as discussed in the Summary section, and form the basis for\nfurther research in energy-efficient control techniques for stabilizing a bicycle robot....
In this paper, a novel hybrid strategy is proposed for unmanned surface vehicle (USV) formation control.The strategy is divided\ninto two subsystems: a virtual velocity controller based on the bioinspired model and a dynamic controller based on the slidingmode\nmodel.The proposed control scheme solves the problem of a speed jump that occurs in the traditional backsteppingmethod\nwhen the margin of error increases suddenly, and it also satisfies the actuator control constraint. Additionally, a dynamic controller\nis designed, combining the sliding mode with the proposed virtual controller, to avoid the traditional chattering problem. System\nstability is proven by the Lyapunov theory. Simulation results verify the effectiveness of the proposed controller....
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