Development of the Variable-Rate Transymmetric Motion With Discretely Vanishing Shock

1984 ◽  
Vol 106 (1) ◽  
pp. 109-113 ◽  
Author(s):  
S. N. Kramer
Keyword(s):  
Constant Velocity ◽  
Angular Displacement ◽  
Operating Cost ◽  
Dynamic Responses ◽  
Variable Rate ◽  
Constant Acceleration ◽  
Functional Relationships ◽  
Rest Position ◽  
New Type ◽  
Velocity Motion

In industry when a link, crank, or other mechanical component is to be rotated from one rest position to another, it is necessary to establish appropriate functional relationships for angular displacement, velocity, and acceleration versus time such that the output motion satisfies certain kinematic and dynamic requirements. In the work presented here, a new type of motion is developed which has distinct advantages over constant velocity motion, constant acceleration motion, simple harmonic motion, cycloidal motion, and polynomial motions. The “variable-rate transymmetric” motion allows a designer to assign specific portions of the motion to be described by a linearly varying acceleration and other portions by a constant acceleration. As a result, the designer can decrease the power required, decrease the operating cost, and decrease dynamic responses such as shock, vibration, and shaking force.

Development of the Tri-Level Variable Rate Trajectory With Discretely Vanishing Shock for Optimum Design

1988 ◽  
Vol 110 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Steven N. Kramer ◽  
Richard L. Curran
Keyword(s):  
Operating Cost ◽  
Robotic Manipulators ◽  
Dynamic Responses ◽  
Variable Rate ◽  
Time Intervals ◽  
The One ◽  
Mechanical Devices ◽  
Level Variable ◽  
General Motion ◽  
General Method

The tri-level variable rate trajectory is a general motion which can be applied to programmable controllers, robotic manipulators, mechanisms, and mechanical devices where the input crank orientation, velocity, and acceleration vary with time. In the work presented here, the tri-level variable rate trajectory is an extension of the variable-rate trans-symmetric motion developed by the first author in 1984. That motion and the one developed here consist of discrete segments of constant and linearly varying accelerations occurring over specified time intervals, thereby providing versatile programmable trajectories with several advantages over the constant acceleration motion, simple harmonic motion, cycloidal motion, and the popular polynomial trajectories used in robotics. The tri-level variable-rate trajectory allows much more control of the acceleration contour of the motion and as a result, there is a decrease in the power required, a decrease in the operating cost, and a decrease in dynamic responses such as shock, vibration, and shaking force and virtual elimination of the overshoot problem that sometimes accompanies the polynomial segment motions. This is a general method which can be applied to many applications. The results of applying this trajectory to a complex machine controller are presented as an example.

The sensitivity of economic gains from high-speed planting

2017 ◽  
Vol 8 (2) ◽  
pp. 662-667
Author(s):  
C. R. Dillon ◽  
J. Shockley ◽  
T. Mark
Keyword(s):  
Optimization Model ◽  
Technological Progress ◽  
High Speed ◽  
Operating Cost ◽  
Cost Savings ◽  
Variable Rate ◽  
Net Returns ◽  
Variable Rate Application ◽  
Technology Changes ◽  
Profit Potential

Recent technological progress in high-speed planting (HSP) warrants economic analysis of its potential. A whole farm optimization model of a 1000 ha Kentucky, USA corn and soybean operation finds that operating cost savings (labor, fuel, tractor repairs) and yield increases couple in recovering annual ownership costs of HSP technology. Changes in farm net returns are positive for all 12-row planter scenarios and all double speed cases for the 16-row planter but not for a 50% increase in speed with the 16-row planter. The greatest profit potential occurred when adopting the combination of HSP and variable rate application (VRA), with increased net returns of up to 6.57% compared to conventional speed no VRA for the 12-row planter.

Dynamic Modelling and Solutions for a Transmission Mechanism With Flexible Support

1997 ◽  
Author(s):  
Liu Hongzhao ◽  
E. Appleton ◽  
Su Zhixiao ◽  
Zhang Shengning ◽  
Cao Weiqing
Keyword(s):  
Dynamic Modelling ◽  
Analytical Form ◽  
Step Function ◽  
Transmission Mechanism ◽  
Dynamic Responses ◽  
Multiple Point ◽  
Analysis And Design ◽  
Flexible Support ◽  
Stable Conditions ◽  
New Type

Abstract In this work, the motion differential equations for a multiple-point meshing mechanism with flexible support are established by the Lagrange formula, and solved using a Laplace transform approach. The stable conditions and the formula for calculating this system’s natural frequencies are given and the general dynamic responses, in analytical form, are developed. The analysis pays special attention to the zero state response to a step function and constant loading inputs. Furthermore, the dynamic torques acting on the basic shaft and torsional bar are also discussed. This research lays the foundation for the analysis and design of this new type of transmission mechanism.

IMM-UKF-TFS Model-based Approach for Intelligent Navigation

2013 ◽  
Vol 66 (6) ◽  
pp. 859-877 ◽  
Author(s):  
M. Malleswaran ◽  
V. Vaidehi ◽  
S. Irwin ◽  
B. Robin
Keyword(s):  
Kalman Filter ◽  
Constant Velocity ◽  
Unscented Kalman Filter ◽  
Interacting Multiple Model ◽  
Multiple Model ◽  
State Variables ◽  
Constant Acceleration ◽  
Positional Accuracy ◽  
Model Based ◽  
Novel Approach

This paper aims to introduce a novel approach named IMM-UKF-TFS (Interacting Multiple Model-Unscented Kalman Filter-Two Filter Smoother) to attain positional accuracy in the intelligent navigation of a manoeuvring vehicle. Here, the navigation filter is designed with an Unscented Kalman Filter (UKF), together with an Interacting Multiple Model algorithm (IMM), which estimates the state variables and handles the noise uncertainty of the manoeuvring vehicle. A model-based estimator named Two Filter Smoothing (TFS) is implemented along with the UKF-based IMM to improve positional accuracy. The performance of the proposed IMM-UKF-TFS method is verified by modelling the vehicle motion into Constant Velocity-Coordinated Turn (CV-CT), Constant Velocity – Constant Acceleration (CV-CA) and Constant Acceleration-Coordinated Turn (CA-CT) models. The simulation results proved that the proposed IMM-UKF-TFS gives better positional accuracy than the existing conventional estimators such as UKF and IMM-UKF.

Extended least square unbiased FIR filter for target tracking using the constant velocity motion model

2017 ◽  
Vol 15 (2) ◽  
pp. 947-951 ◽  
Author(s):  
Jung Min Pak ◽  
Pyung Soo Kim ◽  
Sung Hyun You ◽  
Sang Seol Lee ◽  
Moon Kyou Song
Keyword(s):  
Target Tracking ◽  
Constant Velocity ◽  
Fir Filter ◽  
Least Square ◽  
Motion Model ◽  
Unbiased Fir Filter ◽  
Velocity Motion

Design of a New Bearing on the Large Net Shell Roof Tank

2012 ◽  
Author(s):  
Zhiping Chen ◽  
Huan Gao ◽  
Wenjing Guo ◽  
Fucai Chen ◽  
Ji Wang ◽  
...  
Keyword(s):  
Stability Analysis ◽  
Radial Displacement ◽  
Angular Displacement ◽  
Live Load ◽  
Tank Wall ◽  
Storage Tanks ◽  
Partial Structure ◽  
New Type ◽  
Bearing Structure ◽  
Ansys Workbench

The structure of the plate rib roof can’t meet the need of the constantly enlarging storage tanks, thus more steel/aluminum net shell roofs have been used on the large storage tanks. The bearing between the roof and the tank wall is a key component, because it directly affects the strength and stability of the net shell roof. In this paper, a new type of net shell roof bearing structure is proposed in order to relieve the stress on the bearing and the net shell roof. The proposed structure has several features compared with the existing bearings: the net shell roof with the new bearing can allow a certain amount of radial displacement, and the bearing can also rotate within a certain angle. According to the actual loading status, strength and stability analysis of the overall net shell roof and the bearing’s partial structure are carried out respectively. The overall model of the net shell roof is established by ANSYS, and different boundary conditions are defined on the roof under two working conditions of “full-span live load” and “half-span live load”. Then the overall static strength calculation and stability analysis of the roof are completed. Based on the results of the overall analysis, the strength of the bearing’s partial model is analyzed in ANSYS Workbench. Research shows that when the net shell roof is under load, the roof is allowed to make radial displacement and the bearing to make angular displacement. Thus the burden on the bearing and the net shell roof is relieved, and the strength and stability of the overall roof meet the requirements. Moreover, many regions of the bearing can share the horizontal force, which helps to reduce the load on the bolts and improve the safety of the bearing structure. And the strength of the bearing meets the requirements.

scholarly journals The Onset Threshold of Cybersickness in Constant and Accelerating Optical Flow

2020 ◽  
Vol 10 (21) ◽  
pp. 7808
Author(s):  
Jiwon Kim ◽  
Taezoon Park
Keyword(s):  
Optical Flow ◽  
Constant Velocity ◽  
Human Subject ◽  
Rotational Axis ◽  
Constant Acceleration ◽  
Severe Nausea ◽  
Particle Field ◽  
Human Subject Experiment ◽  
Experimental Findings ◽  
Subject Experiment

This study investigated the principal translational or rotational axis that evokes the most severe cybersickness by detecting constant velocity and acceleration thresholds on the onset of cybersickness. This human subject experiment with 16 participants used a 3D particle field with movement directions (lateral, vertical, yaw, or pitch) and motion profiles (constant velocity or constant acceleration). The results showed that the threshold of pitch optical flow was suggestively lower than that of the yaw, and the vertical threshold was significantly lower than the lateral. Still, there was no effect of scene movement on the level of cybersickness. In four trials, the threshold increased from the first to the second trial, but the rest remained the same as the second one. However, the level of cybersickness increased significantly between the trials on the same day. The disorientation-related symptoms occurred on the first trial day diminished before the second trial day, but the oculomotor-related symptoms accumulated over the days. Although there were no correlations between the threshold and total cybersickness severity, participants with a lower threshold experienced severe nausea. The experimental findings can be applied in designing motion profiles to reduce cybersickness by controlling the optical flow in virtual reality.

On the Discussion of the Damping Reduction Factors in the Constant Acceleration Region for ATC-40 and FEMA-273

2003 ◽  
Vol 19 (4) ◽  
pp. 1001-1006 ◽  
Author(s):  
Yu-Yuan Lin ◽  
Meng-Hao Tsai ◽  
Kuo-Chun Chang
Keyword(s):  
Constant Velocity ◽  
Response Spectra ◽  
Design Practice ◽  
Velocity Range ◽  
Acceleration Region ◽  
Constant Acceleration ◽  
Reduction Factors

According to the ATC-40 (1996) and FEMA-273 (1997) documents, the damping reduction factors for the constant acceleration range of the design response spectra are larger than those for the constant velocity range of those. This trend is contrary to the results obtained from several recent studies and may lead to underestimates of the high-damped design response spectra. This paper points out the issue and suggests further examinations of the factor in the constant acceleration region with potential revision to design practice.

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