Towards Oscillation Reduction in Forestry Cranes

2016 ◽  
Author(s):  
Szabolcs Fodor ◽  
Carlos Vázquez ◽  
Leonid Freidovich ◽  
Nariman Sepehri
Keyword(s):  
Control Method ◽  
Control Technique ◽  
Input Shaping ◽  
Pressure Measurements ◽  
Heavy Duty ◽  
Easy Task ◽  
Input Shaping Control ◽  
Aggressive Signals

Smooth operation of heavy-duty forestry cranes is not an easy task for the operators with the current joystick-based control method that is complex and non-intuitive. Moreover, abrupt movements of the same joysticks provoke aggressive signals that can lead to oscillatory motions in the actuators and in the entire crane. These oscillations, not only contribute to wear of the joint actuators but also can cause damage to both the operators and the environment; therefore, they must be attenuated. The proposed approach in this paper uses the popular input shaping control technique combined with a practical switching logic to deal with different frequency payload oscillations induced by the motion of the inner boom actuator of a forwarder crane. The results show a significant improvement in terms of visible oscillation reduction monitored through their appearance in the torque signal computed from pressure measurements. Experiments performed on a down-sized forestry crane verifies the effectiveness of the approach.

Human Operator Learning on Double-Pendulum Bridge Cranes

2007 ◽  
Author(s):  
Dooroo Kim ◽  
William Singhose
Keyword(s):  
Control Method ◽  
Performance Testing ◽  
Human Operator ◽  
Input Shaping ◽  
Double Pendulum ◽  
Bridge Crane ◽  
Theoretical Limit ◽  
Control Scheme ◽  
Human Operators ◽  
Input Shaping Control

Oscillation of crane payloads makes it challenging to manipulate payloads quickly, accurately, and safely. The problem is compounded when the payload creates a double-pendulum effect. This paper evaluates an input-shaping control method for reducing double-pendulum oscillations. Human operator performance testing on a 10-ton industrial bridge crane is used to verify the effectiveness and robustness of the method. The tests required the operators to drive the crane numerous times over a period of eight days. Data from these experiments show that human operators perform manipulation tasks much faster and safer with the proposed control scheme. Furthermore, considerably less operator effort is required when input shaping is used to limit the oscillation. These experiments also show that significant learning occurred when operators did not have the aid of input shaping. However, the performance never approached that achieved with input shaping without any training. With input shaping enabled, only moderate learning occurred because operators were able to drive the crane near its theoretical limit during their first tests.

Dynamics and Control of Bridge Cranes Transporting Distributed-Mass Payloads

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Raymond Manning ◽  
Jeffrey Clement ◽  
Dooroo Kim ◽  
William Singhose
Keyword(s):  
Control Method ◽  
Single Mode ◽  
Input Shaping ◽  
Double Pendulum ◽  
Efficient Operation ◽  
Performance Improvements ◽  
Dynamics And Control ◽  
Damped Oscillation ◽  
And Control ◽  
Input Shaping Control

The large-amplitude and lightly-damped oscillation of crane payloads is detrimental to safe and efficient operation. The problem is further complicated when the payload creates a double-pendulum effect. Previous researches have shown that single-mode oscillations can be greatly reduced by properly shaping the inputs to the crane motors. This paper builds on previous developments by thoroughly describing the double-pendulum dynamic effects as a function of payload parameters and the crane configuration. Furthermore, an input-shaping control method is developed to suppress double-pendulum oscillations created by a payload with distributed-mass properties. Experiments performed on a 10-ton industrial bridge crane verify the effectiveness of the method. A critical aspect of the testing was human operator studies, wherein numerous operators utilized the input-shaping controller to perform manipulation tasks. The performance improvements provided by the input-shaping controller, as well as operator learning effects, are reported.

Combined Input Shaping and Feedback Control of a Double-Pendulum System Subject to External Disturbances

2015 ◽  
Author(s):  
Robert Mar ◽  
Anurag Goyal ◽  
Vinh Nguyen ◽  
Tianle Yang ◽  
William Singhose
Keyword(s):  
Feedback Control ◽  
Control Method ◽  
Open Loop ◽  
Input Shaping ◽  
Double Pendulum ◽  
External Disturbances ◽  
Pendulum System ◽  
Modeling Uncertainties ◽  
Point To Point ◽  
Input Shaping Control

A control system combining input shaping and feedback is applied to a double-pendulum bridge crane subjected to external disturbances. The external disturbances represent naturally occurring forces, such as gusting winds. The proposed control method achieves fast point-to-point response similar to open-loop input-shaping control. It also minimizes transient deflections and disturbance-induced residual swing using the feedback control. Effects of parameters such as the mass ratio of the double-pendulum, suspension length ratio, and the traveled distance were studied via numerical simulation and hardware experiments. The controller effectively suppresses the disturbances and is robust to modeling uncertainties and task variations.

Two-degree-of-freedom Controller Design for Uncertain Processes Using Input/output Linearization Control Technique

2011 ◽  
Vol 11 (1) ◽  
pp. 16 ◽  
Author(s):  
Pisit Sukkarnkha ◽  
Chanin Panjapornpon
Keyword(s):  
Disturbance Rejection ◽  
Control Structure ◽  
Control Method ◽  
Random Noise ◽  
Degree Of Freedom ◽  
Control Technique ◽  
Input Output ◽  
Tracking Controller ◽  
Two Degree Of Freedom ◽  
Input Output Linearization

In this work, a new control method for uncertain processes is developed based on two-degree-of-freedom control structure. The setpoint tracking controller designed by input/output linearization technique is used to regulate the disturbance-free output and the disturbance rejection controller designed is designed by high-gain technique. The advantage of two-degree-of-freedom control structure is that setpoint tracking and load disturbance rejection controllers can be designed separately. Open-loop observer is applied to provide disturbance-free response for setpoint tracking controller. The process/disturbance-free model mismatches are fed to the disturbance rejection controller for reducing effect of disturbance. To evaluate the control performance, the proposed control method is applied through the example of a continuous stirred tank reactor with unmeasured input disturbances and random noise kinetic parametric uncertainties. The simulation results show that both types of disturbances can be effectively compensated by the proposed control method.

Research on a New Type of Lithium Battery String Equalization and Management System

2011 ◽  
Vol 383-390 ◽  
pp. 1470-1476
Author(s):  
Hao Wang ◽  
Ding Guo Shao ◽  
Lu Xu
Keyword(s):  
Lithium Batteries ◽  
Management System ◽  
Lithium Battery ◽  
Large Scale ◽  
Control Method ◽  
Balance Control ◽  
Industrial Applications ◽  
Control Technique ◽  
New Type ◽  
Management Functions

Lithium battery has been employed widely in many industrial applications. Parameter mismatches between lithium batteries along a series string is the critical limits of the large-scale applications in high power situation. Maintaining equalization between batteries is the key technique in lithium batteries application. This paper summarizes normal equalization techniques and proposed a new type of lithium Battery Equalization and Management System (BEMS) employing the isolated DC-DC converter structure. The system is integrated both equalization functions and management functions by using distributed 3-level controlled structure and digital control technique. With this control method the flexibility of the balance control strategy and the compatibility for different battery strings are both improved dramatically. The experimental results show optimizing equalization, efficiency and the battery string life span has been extended.

Effect of Input Shaping on Response of Inertia Plants

2011 ◽  
Vol 121-126 ◽  
pp. 2676-2680
Author(s):  
Ming Xiao Dong ◽  
Rui Chuan Li ◽  
Qin Zu Xu
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Control Systems ◽  
Setting Time ◽  
Input Shaping ◽  
Pd Controller ◽  
Residual Vibration ◽  
Simulation Results ◽  
Analytical Expressions ◽  
Input Shaping Control

A poorly designed control system can lead to excessive residual vibration and long setting time. This paper investigates the effect of input shaping on control efficiency. To perform this investigation, we design a PD controller combined with input shaping for an inertia plant. We then subject it to four standard types of inputs. The responses of the control systems are described by analytical expressions. The performances of PD control and PD combined with input-shaping control are thoroughly analyzed and compared. Simulation results show that PD feedback control enhanced with input shaping minimizes overshoot and setting time.

scholarly journals A Cable-Passive Damper System for Sway and Skew Motion Control of a Crane Spreader

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
La Duc Viet ◽  
Youngjin Park
Keyword(s):  
Motion Control ◽  
Input Shaping ◽  
Passive System ◽  
Time Integral ◽  
Passive Damper ◽  
Optimal Damping ◽  
Control Command ◽  
System Energy ◽  
Energy Dissipated ◽  
Input Shaping Control

While the crane control problem is often approached by applying a certain active control command to some parts of the crane, this paper proposes a cable-passive damper system to reduce the vibration of a four-cable suspended crane spreader. The residual sway and skew motions of a crane spreader always produce the angle deflections between the crane cables and the crane spreader. The idea in this paper is to convert those deflections into energy dissipated by the viscous dampers, which connect the cables and the spreader. The proposed damper system is effective in reducing spreader sway and skew motions. Moreover, the optimal damping coefficient can be found analytically by minimizing the time integral of system energy. The numerical simulations show that the proposed passive system can assist the input shaping control of the trolley motion in reducing both sway and skew responses.

scholarly journals INPUT SHAPING CONTROL TO REDUCE RESIDUAL VIBRATION OF A FLEXIBLE BEAM

2016 ◽  
Vol 32 (1) ◽  
pp. 75-90 ◽  
Author(s):  
Quoc Chi Nguyen ◽  
Ha Quang Thinh Ngo
Keyword(s):  
Control Algorithms ◽  
Input Shaping ◽  
Flexible Beam ◽  
Residual Vibration ◽  
Motion System ◽  
Damped System ◽  
Input Shaping Control

In this paper, three control algorithms based on input shaping method are developed to suppress the residual vibration of a flexible beam. The flexible beam is modeled as an under-damped system. Three input shapers, ZV, ZVD, and ZVDD, are used to control the flexible beam. The three control algorithms are implemented by using the Mechatrolink-III motion system. The experiments are performed to verify the effectiveness of the three control algorithms.

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