AUTOMATICALLY STEERED SELF-PROPELLED VEHICLE

• US 3,744,586 A
• Filed: 10/05/1971
• Issued: 07/10/1973
• Est. Priority Date: 10/07/1970
• Status: Expired due to Term

• Current Assignee: Erich Leinauer
• Original Assignee: Erich Leinauer
• Inventors: Leinauer, Erich
• Primary Examiner(s): Hersh, Benjamin
• Assistant Examiner(s): Paperner, Leslie J.
• Application Number:
  US05/186,678
• Time in Patent Office: 644 Days
• Field of Search: 180/79.1,98 318/587 340/282 250/202 343/7ED
• US Class Current: 180/401
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9317 Driving backwards
• CPC Class Codes: G01S 2013/9318 Controlling the steering
• CPC Class Codes: G01S 2013/9323 Alternative operation using light waves
• CPC Class Codes: G01S 2013/9324 Alternative operation using ultrasonic waves
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles

Abstract

A self-propelled vehicle is automatically reversed and steered to a new path if sensors thereon sense an obstruction surrounding an area, or an obstacle in the area so that the vehicle moves forward, rearward and laterally over the entire unobstructed area for treating the same with a tool, such as a brush or agricultural implement. The forward and rearward movements are maintained along straight paths independently of irregularities prevelant in the area, tolerances in the steering control system of the vehicle or other such influences.

Claims

1. An apparatus for maintaining a substantially fixed relative orientation between at least one partially reflecting reference surface and a steered self-propelled vehicle, particularly a vehicle for movement over the unobstructed portion of an area having obstructions, comprising a vehicle frame;

motor means on said frame for propelling said vehicle at least in one direction;

steering means on said frame for steering said vehicle so that the course of the vehicle is normally at least substantially parallel to said reference surface;

at least one transmitter means for transmitting a signal in the direction of said reference surface;

at least one receiver means for receiving the reflected signal from said reflecting surface when said vehicle deviates from said course; and

regulating means connected to said receiver means and to said steering means for generating a control signal in response to said reflected signal for activating said steering means when said reflected signal is received by said receiver means to alter the course of the vehicle and cause the vehicle to resume its movement in substantial parallelism with said reference surface, wherein said receiver means includes a plurality of receiver sensors arranged in a predetermined order with respect to the transmitted signal, each sensor of said receiver means bEing positioned to receive said reflected signal for different relative orientations of said vehicle with respect to said reference surface and being calibrated to generate output sensing signals which are a function of the degree by which said vehicle deviates from its normal course.

2. An apparatus as defined in claim 1, further comprising sensing means on said frame for generating a signal when sensing an obstruction during movement in said direction;

and a control device including steering control means responsive to said latter signal of said sensing means to operate said steering means to change the direction of movement of said vehicle so that said vehicle continues to move on said unobstructed portion of said area.

3. An apparatus as defined in claim 1, further including rotatable means for supporting said transmitter and receiver means and for rotating said transmitter and receiver means in equal amounts in relation to said vehicle frame, whereby any surface surrounding said vehicle can be chosen to be said reference surface.

4. An apparatus as defined in claim 1, wherein two transmitter means and two corresponding receiver means are arranged on said frame, each transmitter means transmitting a signal towards a corresponding reference surface.

5. An apparatus as defined in claim 1, wherein said transmitter and receiver means comprise a light source and photo-electric means respectively, and said transmitter and reflected signals comprise light beams.

6. An apparatus as defined in claim 1, wherein said transmitter and receiver means comprise acoustic transmitter and acoustic receiver means respectively, and said transmitted and reflected signals comprise acoustic signals.

7. An apparatus as defined in claim 1, wherein said output sensing signals generated by said sensors appear in quantized form, and wherein said regulating means includes a digital-to-analog converter which is connected to said sensors for converting said output sensing signals into an analog output signal.

8. An apparatus as defined in claim 7, wherein said regulating means includes a variable gain amplifier, having means for changing its gain, which is connected to said digital-to-analog converter and to said steering means for amplifying said analog output signal to yield said control signal for appropriately activating, at a predetermined distance of said vehicle from said reference surface, said steering means.

9. An apparatus as defined in claim 8, wherein said means for changing the gain includes a potentiometer having a movable portion, said analog output signal being applied across the potentiometer and said amplifier input being connected to said movable portion.

10. An apparatus as defined in claim 9, further comprising position changing means for changing the position of said movable portion as a function of and proportional to the distance between said vehicle and said reference surface, whereby said control signal is substantially independent of the latter distance.

11. An apparatus as defined in claim 10, wherein said wheels of said vehicle are rotatable 90* from their normal position in response to an appropriate control signal to thereby enable the vehicle to move in a direction perpendicular to said reference surface to thereby change its distance relative to said surface, and wherein said position changing means comprises a servomotor operatively connected to said movable portion to move its position when said servomotor is energized;

an AND control switch having an output and two input points and which generates an output at said output point only when appropriate signals are applied to both input points to energize said servomotor, one input point of said control switch being connected to said steering control means to sense the presence of said appropriate control signal, the other input point being connected to a control device and said motor means to sense when the wheels are energized to thereby detect when the vEhicle is changing its distance with respect to said reference surface, whereby said movable portion position and the gain of the amplifier is changed only in relation to changes in distance of said vehicle from said reference surface.