Land vehicle guidance method and apparatus
First Claim
1. In a guided ground vehicle having sensor means for sensing deviations of said sensor means from a reference path having a straight portion and a curved portion, command signal forming means responsive to signals from said sensor means for providing steering command signals which vary in accordance with a predetermined function of the position of said sensor means relative to said path, and steering means responsive to said command signals for steering said vehicle, the combination of:
- turning control means operative while said vehicle travels along said curved portion of said path for modifying said steering command signals by an amount substantially inversely commensurate with the radius of curvature of said curved portion.
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Accused Products
Abstract
To enable a vehicle which can automatically track a substantially straight guidewire or the like at high speeds with prescribed dynamic characteristics to also track distinct guidewire curves with similar characteristics, an added signal which is a function of guidewire curvature and vehicle wheelbase is superimposed on the command signal derived from a tracking sensor to modify the command signal applied to a steering servo or other steering means while the vehicle negotiates a curve.
37 Citations
30 Claims
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1. In a guided ground vehicle having sensor means for sensing deviations of said sensor means from a reference path having a straight portion and a curved portion, command signal forming means responsive to signals from said sensor means for providing steering command signals which vary in accordance with a predetermined function of the position of said sensor means relative to said path, and steering means responsive to said command signals for steering said vehicle, the combination of:
- turning control means operative while said vehicle travels along said curved portion of said path for modifying said steering command signals by an amount substantially inversely commensurate with the radius of curvature of said curved portion.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 24, 25, 26, 27, 28, 29)
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23. The method of automatically steering a vehicle along a reference path having a straight section and a curved section by means of a sensor operable to provide signals representing deviations of said vehicle from said reference path, comprising the steps of:
- processing said signals from said sensor to provide a steering command signal;
steering said vehicle in response to said steering command signal;
monitoring said signals from said sensor to automatically stop said vehicle if said signals from said sensor exceed a predetermined value; and
varying said steering command signal by an amount inversely commensurate with the radius of curvature of said curved section while said vehicle travels along said curved section, thereby preventing said signals from said sensor from exceeding said predetermined value.
- processing said signals from said sensor to provide a steering command signal;
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30. An automatic guidance system for a ground vehicle, comprising a guidewire defining a reference path having straight sections and curved sections, and a plurality of signalling means spaced along said guidewire adjacent points at which curvature of said guidewire changes, said vehicle having a steerable wheel means, sensor means for sensing deviations of said vehicle from said reference path and providing steering signals to control the instantaneous steering angle of said steerable wheel means during travel of said sensor means along both said straight sections and said curved sections, and turning control means for modifying said steering signals during travel of said sensor means along said curved sections by superimposing on said steering signals turning signals inversely commensurate with the radius of curvature of said curved sections thereby to provide finite steering angles at said steerable wheel means even when said deviations are zero, said signalling means being operative to enable or disable the turning control means on said vehicle as said vehicle passes respective ones of said signalling means.
Specification