Steering Control Systems--Laboratory Test Procedure Heavy Trucks

1998 ◽  
Author(s):  
Keyword(s):  
Laboratory Test ◽  
Control Systems ◽  
Test Procedure ◽  
Steering Control ◽  
Heavy Trucks

Letters to the Editor

PEDIATRICS ◽  
1980 ◽  
Vol 66 (3) ◽  
pp. 482-482
Author(s):  
J. Swanson
Keyword(s):  
Laboratory Test ◽  
Test Procedure ◽  
Drug Trial ◽  
Short Term ◽  
Letters To The Editor ◽  
Stimulant Drug ◽  
Stimulant Drugs ◽  
Hyperactive Children ◽  
Initial Work ◽  
Conservative Bias

In their letter, McLaughlin and Tso have misinterpreted the purpose of the short-term diagnostic drug trial we have proposed (Pediatrics 61:21, 1978). We developed our laboratory test procedure to screen out potential adverse responders, in order to prevent their mistreatment with stimulant drugs. We feel that this conservative bias is necessary, since there has been general agreement since Bradley's (1939, 1950) initial work that not all behaviorally hyperactive children have a favorable response to stimulant drug.1,2

scholarly journals The Effect of Large-Scale Structures on the Stability of Coal-Face Steering

1984 ◽  
Vol 198 (1) ◽  
pp. 29-40 ◽  
Author(s):  
J B Edwards
Keyword(s):  
Control Systems ◽  
Large Scale ◽  
Steering System ◽  
Rigid Support ◽  
Steering Control ◽  
Coal Face ◽  
Large Scale Structures ◽  
General Terms ◽  
Scale Structures ◽  
The Stability

Simplified models of piecewise rigid support structures for power-loaders operating on longwall coal-faces are shown to be amenable to analysis by z-transform methods. Such analysis predicts that increasing sufficiently the length of the sub-sections of the structure (compared to the inherent delay within the vertical steering system of the machine) should stabilize the vertical steering of the entire coalface. Increasing the width of the structure to embrace more than two consecutive cut floors is shown analytically to eliminate the need for electronic tilt-feedback in control systems. In general terms, these analytical predictions are shown to hold good in detailed simulations of the system that eliminate the simplifications demanded by the analytical method. The general conclusion of the work is therefore that an increase in the size of support structure segments can potentially reduce the complexity of steering control systems. The size-increase must be substantial, e.g. to four to five times the size of conventional structures.

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