Automatic guided vehicle and method for controlling travel thereof

• US 5,170,351 A
• Filed: 09/18/1990
• Issued: 12/08/1992
• Est. Priority Date: 09/18/1990
• Status: Expired due to Fees

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsumoto, Yoshihiro, Nemoto, Toshikazu
• Primary Examiner(s): Black, Thomas G.
• Application Number:
  US07/584,578
• Time in Patent Office: 812 Days
• Field of Search: 364/424.02, 364/426.04, 180/167, 180/168, 180/169, 318/568.12
• US Class Current: 701/23
• CPC Class Codes: G05D 1/0255 using acoustic signals, e.g. ultra-sonic singals sonar systems designed for anti-collision purposes G01S15/93

Abstract

An automatic guided vehicle has a detector for detecting a distance between the vehicle and an object and then outputting a distance signal, and a controller for controlling the speed of the vehicle according to the distance signal and for operating in one of a succeeding vehicle mode under which the distance between the vehicle and a preceding automatic guided vehicle is small and a preceding vehicle mode under which the distance maintained therebetween will be larger. A travel control method for controlling a travel of the automatic guided vehicle includes the steps of: dividing an entire travel path into sections, and operating the vehicle in one of the modes in each section. The succeeding vehicle mode allows the vehicle to travel in a group with a small distance between the vehicle and the preceding vehicle, and the preceding vehicle mode allows a group of the vehicles to be disorganized and the vehicles to travel at a predetermined speed so that the distance therebetween is larger.

Claims

1. An automatic guided vehicle comprising:

a vehicle body;

driving means mounted on the vehicle body for driving the vehicle at variable speeds;

detecting means for detecting the distance between the vehicle and an object and outputting a signal indicative of said distance; and

control means operatively connected to said detecting means and to said driving means for receiving said signal from said detecting means, and for selectively operating under a first mode in which said driving means is controlled by the control means to both slow down the vehicle when the signal output by said detecting means is indicative of the detected distance being less than a first mode predetermined distance and to speed up the vehicle when the signal is indicative of the detected distance being greater than a first mode predetermined distance and a second mode in which said driving means is controlled to slow down the speed of the vehicle as long as the signal output by said detecting means is indicative of said distance being less than a second mode predetermined distance greater than each said first mode predetermined distance,

whereby a group of the vehicles will travel closer together when said control means is operating in said first mode than when said control means is operating in said second mode.

2. A method for controlling the travel of an automatic guided vehicle along a path, said method comprising the steps of:

detecting the distance between the vehicle and a vehicle immediately downstream therefrom along a common travel path as the vehicles travel along said common travel path;

controlling the vehicle to maintain a first predetermined distance from the vehicle immediately downstream thereof along a first predetermined section of said common travel path based on the distance detected therebetween, and

controlling the vehicle to maintain at least a second predetermined distance, that is larger than said first predetermined distance, from the vehicle immediately downstream thereof along a second predetermined section of said common travel path downstream of said first section based on the distance detected therebetween,

whereby a group of the vehicles will travel closer together along said first predetermined section of said common travel path than along said second predetermined section of said common travel path.