Model reduction and composite control for overhead hoist transport system by singular perturbation technique

One of the most critical issues in overhead cranes is the swing of a suspended load while the crane starts to move and accelerates, changes the movement direction, breaks or stops. This can lead to severe damage, and therefore several methods have been applied to damp the load swings. Most of these methods are based on information about the swing angle of a suspended load. In traditional methods, camera vision, acceleration or inclinometers sensors, simple pendulums and other types of sensors have been used. Generally, a method is desired if it can estimate the swing angle with the least equipment costs, while using an uncomplicated calculation method and the minimum sensitivity to environmental situations and industrial noises. In this paper, a new algorithm is proposed to estimate the swing angle. To do so, the supplied voltage and current of the induction motor which drives the trolley are measured, and then using a new proposed method based on a dynamic analysis of the mathematical dynamic model, the swing angle is estimated and is used in the controller system to damp the swings. The proposed method is verified by means of computer simulations.

Section: Introductionmentioning

confidence: 99%

Sensorless anti-swing control for overhead crane using voltage and current measurements

Gholabi

Ebrahimi

Yousefi

et al. 2013

“…However, the efficiency improvements reported in these studies were limited. Sliding mode control (SMC), also called variable structure system (VSS), is based on the sliding motion of the switching surface and is an ideal candidate for designing a control system with good robustness (Li and Wang, 2011;Song and Sun, 2012;Tsai et al, 2012). Applications of SMC to overhead crane designs have also been reported.…”

Section: Introductionmentioning

confidence: 99%

Parallel neural network combined with sliding mode control in overhead crane control system

Lee

Huang

Shih

et al. 2012

A novel control for a nonlinear two-dimensional (2-D) overhead crane is proposed. Instead of the complex design procedures used in classic methods, the proposed scheme combines the principles of neural networks (NNs) and variable structure systems (VSS) to derive control signals needed to drive the cart smoothly, rapidly and with limited payload swing. The merits include the robustness and model-free properties of the sliding mode and neural based controllers, respectively. Simulations performed using a scaled 2-D mathematical model of the crane confirm the effectiveness of the proposed method.

Dynamic analysis and collision prevention for μ-disc-type inductive micro-motor driven by solenoids

Tsai

Lin

2013

Self Cite

An innovative μ-disc-type inductive micro-motor is proposed and studied in this paper. The novel 3D solenoid-type electromagnetic poles are designed and fabricated by dry isotropic etching technique so that the output torque of the inductive motor can be greatly increased even though a simpler fabrication procedure is employed. On the other hand, the order-reduced dynamic model for the proposed micro-motor is established by using the singular perturbation theory. Based on the order-reduced model, a composite controller is synthesized to prevent potential collision between the disc and the center bearing by sliding mode control strategy and successfully suppress the unfavorable periodic oscillation, due to eccentricity of the disc, by an anti-swaying policy. Eventually, a few comparisons on several typical operational conditions, such as various vacuum levels, van der waals force and periodic disturbance, are also addressed and presented. The efficacy of the composite controller and the performance of the proposed micro-motor are verified by intensive simulations undertaken via the commercial software, Matlab/Simulink, and the interface module dSpace DS 1104 Board. Finally, the superior performance for the proposed micro-motor is assured, e.g., the collision between the disc and the center bearing can be successfully prevented and a constant spinning speed can be retained even if a certain degree of disturbance and uncertainty abruptly occurs.