Modeling and simulation of electro-hydraulic telescopic elevator system controlled by programmable logic controller

Abstract

Traditional hydraulic <span>cylinders are widely used in industry as load lifting tools. There is difficulty in employing these cylinders in narrow installation space like building elevators as well as they require a long working stroke, so solving this problem requires using the telescopic hydraulic cylinder instead. This cylinder is a unique hydraulic cylinder design that uses a sequence of decreasing diameters to create a long operating stroke in a compact-retracted form. In this work, the Auto Station software is used to build a telescopic hydraulic cylinder model that includes hydraulic elements such as double-acting hydraulic telescopic cylinders, pump, valves, pipeline, and filter, as well as electrical parts such as programmable logic controller (PLC), push-bottoms, and position sensors. The proposed model is operated by a PLC controller and has three floors with an overall height of around 300 cm for lifting a 100 kg payload. The accuracy and validity of this model in lifting big weights were demonstrated by the analytical findings of characteristic curves for cylinder position and velocity. This model can be used a basic reference to analyze and construct hydraulic cylinders with any number of stages. The findings of simulations reveal that a quick change in pressure due to phase change causes multi-phase vibration.</span>

A review on the employment of the hydraulic cylinder for lifting purposes

“…Hady et al [14] employed the 4-stages telescopic cylinder in building a PLC-based elevator system for lifting purposes as shown in Figure 7. The study findings, which included typical curves for cylinder position and speed, demonstrated the simulated model's correctness and believability.…”

“…The theoretical analysis of the telescopic hydraulic cylinder is represented by all of the studies in Table 1, while the studies in Table 2 are concerned with designing and implementing an effective and smooth control of the motion of the telescopic hydraulic cylinder. The elevator system in the studies [13,14] differs from the all previously mentioned cylinders or lifting systems in that it is constructed using a telescopic hydraulic cylinder as a driving mechanism.…”

“…Offer a better riding and reduced steady-state losses Mohammed et al [10], Mohammed et al [11] Controlled the hydraulic elevator speed using a proportional valve and PI controller Effectiveness of using Electro-hydraulic servomechanism to get high comfort & smoothness Mohammed et al [12] Hydraulic elevator controlled by PLC Great outcomes for system control, efficiency, reactivity, & smoothness Al-Hady et al [13], Al-Had et al [14] Employed a telescopic hydraulic cylinder to build PLC-based elevator…”

“…Elevators are classified depending on a variety of factors, but the driving mechanism determines the design and element manufacturing processes. Elevators are classified into three categories based on how they are powered; Electric traction elevators [3]- [9], Hydraulic elevators [10]- [14], and Pneumatic elevators [15]- [17]. A typical hydraulic elevator consumes significantly more energy than a traction elevator.…”

“…The EHS generally consists of three main units including the power unit which is responsible for increasing the power of the fluid, the control unit, which is responsible for controlling the pressures, directions, and velocities with the 1476 time in the system, and the operating unit, which is responsible for obtaining the useful work of the system [20]. The electro-hydraulic system offers several benefits, including a wide speed range, fast response, high durability, and a high power-to-weight ratio, and it is extensively employed in industrial manufacturing, agricultural machinery, and armament systems [1], [14], [21], [22].…”