Technical Note: A two-degree-of-freedom ambulance stretcher suspension: Part 3: Laboratory and road test performance

1998 ◽  
Vol 212 (5) ◽  
pp. 401-407 ◽  
Author(s):  
R. J. Henderson ◽  
J. K. Raine
Keyword(s):  
Test Performance ◽  
Natural Frequencies ◽  
Low Cost ◽  
Mechanical Systems ◽  
Technical Note ◽  
Suspension System ◽  
Degree Of Freedom ◽  
Road Test ◽  
Pneumatic Suspension ◽  
Two Degree Of Freedom

Parts 1 and 2 of this paper gave a design overview and described the dynamics of a prototype two-degree-of-freedom pneumatic suspension for an ambulance stretcher. This concluding part briefly reviews laboratory shaker table and ambulance road test performance of the suspension with passive pneumatic damping. The suspension system is found to offer compact low-cost isolation with lower natural frequencies than achieved in earlier mechanical systems.

scholarly journals Feedback control for two-degree-of-freedom vibration system with fractional-order derivative damping

2017 ◽  
Vol 37 (3) ◽  
pp. 554-564
Author(s):  
Canchang Liu ◽  
Chicheng Ma ◽  
Jilei Zhou ◽  
Lu Liu ◽  
Shuchang Yue ◽  
...  
Keyword(s):  
Feedback Control ◽  
Nonlinear Vibration ◽  
Fractional Order ◽  
Suspension System ◽  
Degree Of Freedom ◽  
Vehicle Suspension ◽  
Vibration System ◽  
Fractional Order Derivative ◽  
Vehicle Suspension System ◽  
Two Degree Of Freedom

A two-degree-of-freedom nonlinear vibration system of a quarter vehicle suspension system is studied by using the feedback control method considered the fractional-order derivative damping. The nonlinear dynamic model of two-degree-of-freedom vehicle suspension system is built and linear velocity and displacement controllers are used to control the nonlinear vibration of the vehicle suspension system. A case of the 1:1 internal resonance is considered. The amplitude–frequency response is obtained with the multiscale method. The asymptotic stability conditions of the nonlinear system can be gotten by using the Routh–Hurwitz criterion and the ranges of control parameters are gained in the condition of stable solutions to the system. The simulation results show that the feedback control can effectively reduce the amplitude of primary resonance, weaken or even eliminate the nonlinear vibration characteristics of the suspension system. Fractional orders have an impact on control performance, which should be considered in the control problem. The study will provide a theoretical basis and reference for the optimal design of the vehicle suspension system.

Design and Construction of a Low Cost of Solar Tracker Two Degree of Freedom (DOF) Based On Arduino

2020 ◽  
Author(s):  
Marthen Dangu Elu Beily ◽  
Rusman Sinaga ◽  
Zilman Syarif ◽  
Mychael G Pae ◽  
Rochani Rochani
Keyword(s):  
Low Cost ◽  
Degree Of Freedom ◽  
Solar Tracker ◽  
Two Degree Of Freedom ◽  
Design And Construction

The Galloping Response of a Two-Degree-of-Freedom System

1974 ◽  
Vol 41 (4) ◽  
pp. 1113-1118 ◽  
Author(s):  
R. D. Blevins ◽  
W. D. Iwan
Keyword(s):  
Steady State ◽  
Closed Form ◽  
Natural Frequencies ◽  
Analytic Solutions ◽  
Degree Of Freedom ◽  
Approximate Analysis ◽  
Stability Criteria ◽  
Integer Multiple ◽  
Two Degree Of Freedom ◽  
Steady State Solutions

The galloping response of a two-degree-of-freedom system is investigated using asymptotic techniques to generate approximate steady-state solutions. Simple closed-form analytic solutions and stability criteria are presented for the case where the two structural natural frequencies are harmonically separated. Examples of the nature of the galloping response of a particular section are presented for the case where the frequencies are harmonically separated as well as for the case where the two natural frequencies are near an integer multiple of each other. The results of the approximate analysis are compared with experimental and numerical results.

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