Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Automatic route guidance vehicle
Reexamination Certificate
2000-07-31
2002-11-19
Nguyen, Tan (Department: 3661)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Automatic route guidance vehicle
C701S019000, C701S033000
Reexamination Certificate
active
06484077
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a travel control system for an assembly carrying vehicle.
2. Description of the Related Art
An assembly carrying vehicle is used to carry the body of an automobile to be assembled in an automobile assembly line of an automobile production factory. Therefore, a system for controlling running or travel of the assembly carrying vehicles is necessary. A conventional assembly carrying vehicle is run along a predetermined energized orbit. An electrical power for the assembly carrying vehicle is supplied to the vehicle through the contact of a brush to the orbit.
The conventional assembly carrying vehicle running or travel control system will be described below. In the conventional assembly carrying vehicle running control system, the assembly carrying vehicle is generally used in a final automobile assembly line, during which parts such as seats, doors, interior, and exterior are mounted on the body after painting.
At first, a different individual work is carried out in each of a plurality of stations disposed along the orbit on which the assembly carrying vehicle runs, manually or by use of a working robot in the final automobile assembly line. The assembly carrying vehicle is moved at a slow speed in the station in which the work is manually carried out, while the assembly carrying vehicle is stopped in a perfectly positioned state in the station in which the work is carried out by use of the working robot. Generally, the manual work is carried out to mount a small part, and the work using the working robot is carried out to mount a large part such as a door. Also, in the respective stations, a height of the body carried by the assembly carrying vehicle from a floor is automatically adjusted to a height at which a worker can easily carry out the mounting work, or an appropriate height when the mounting work is carried out by use of the working robot.
The assembly carrying vehicle running control system has a control apparatus for controlling the whole system. The movement of the assembly carrying vehicle is controlled through communication between the control apparatus and the assembly carrying vehicle. The communication is carried out between a communicating unit of the assembly carrying vehicle and a plurality of access points (AP) connected to the control apparatus.
Conventionally, a fixed point communication system using optical communication has been mainly used for the communication between the assembly carrying vehicle and the access points AP. In recent years, a radio communication system has been used for the communication between the assembly carrying vehicle and the access points AP.
A technique related to such a radio go communication system is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 7-95145). In this reference, it is intended to easily check a communication status in all communication positions on a moving route of an assembly carrying vehicle. In this configuration, the assembly carrying vehicle has a communicating unit for carrying out radio communication with a communicating unit of a ground station. The assembly carrying vehicle communicating unit is provided with a controlling section and a communication position detecting section. The controlling section controls the movement of the assembly carrying vehicle, and also controls a communicating operation of the assembly carrying vehicle communicating unit. The communication position detecting section detects a communication position at which a communication with the ground station communicating unit is carried out. Then, in the conventional assembly carrying vehicle running control system, the controlling section drives the assembly carrying vehicle communicating unit in accordance with the detected result of the communication position detecting section.
When a communication test mode is instructed, the controlling unit controls the assembly carrying vehicle to carry out a test run to pass through each of a plurality of test communication positions. Also, the controlling unit controls the communicating unit to carry out a test communication with the ground station communicating unit in each of the plurality of test communication positions. Moreover, a spectrum spreading communication method may be used in the radio communication.
Next, another conventional technique with regard to the operational control of the assembly carrying vehicle will be described below. At first, a plurality of fixed indication plates are installed on a predetermined orbit on which the assembly carrying vehicle moves. The indication plates are fixedly installed on a floor. A sensor is mounted in the assembly carrying vehicle to detect the indication plate. When detecting one of the plurality of indication plates by use of the sensor, the assembly carrying vehicle acquires an operation pattern data at the detected location. The operation of the assembly carrying vehicle is defined by the operation pattern data from an external unit. The assembly carrying vehicle carries out an operation to retain or maintain a tact pitch distance, a cornering operation or a constant speed operation, until detecting a next one of the plurality of fixed indication plates by use of the sensor.
In this way, according to the conventional technique, a current position control for the assembly carrying vehicle itself is not carried out. Therefore, it is difficult to carry out a position recovery resulting from occurrence of overrun or a position displacement of the assembly carrying vehicle. Also, this requires work for changing the fixed indication plates in association with a line change. Hence, in the above configuration, the line can not be changed flexibly or easily.
Also, in the conventional assembly carrying vehicle running controller system, the control of the assembly carrying vehicle is carried out by the control apparatus through monitoring a status table of the assembly carrying vehicle.
A supersonic sensor is mounted on an assembly carrying vehicle, in order to measure a distance from a preceding assembly carrying vehicle running immediately before. The running speed of the assembly carrying vehicle can be adjusted based on the distance from the preceding assembly carrying vehicle, which is measured by the supersonic sensor. Thus, the assembly carrying vehicle can be moved while keeping a constant interval from the preceding assembly carrying vehicle. When the assembly carrying vehicle is running on a corner on a predetermined orbit, the supersonic sensor may likely sense things other than the preceding assembly carrying vehicle. For this reason, it is impossible to accurately measure the distance from the preceding assembly carrying vehicle on the corner. Hence, when the assembly carrying vehicle is running on the corner, the running control can not be carried out by use of the supersonic sensor. Especially, if the assembly carrying vehicle is urgently stopped on the corner, a succeeding assembly carrying vehicle may collide with the preceding assembly carrying vehicle.
Also, in the conventional assembly carrying vehicle running control system, the running or travel control of the assembly carrying vehicle is carried out through optical communication between the control apparatus and the communicating unit of the assembly carrying vehicle via a relaying unit, which is provided for one of the plurality of fixed indication plates. The assembly carrying vehicle receives control data such as a running operation and the height of a carried member through the communication. Then, the assembly carrying vehicle is moved to the next fixed indication plate based on the control data. For this reason, when trouble occurs in a part of the fixed indication plates, the assembly carrying vehicle can not be correctly controlled.
In conjunction with the above description, a spectrum spreading communication apparatus is disclosed in Japanese Laid Open Patent Application (JP-A-Heisei 5-75573). In this reference, a received signal is subjected to FFT frequency
Inoue Eiichi
Minato Muneatsu
Nakazono Yoshiharu
Unose Noriyuki
Yamamuro Hideya
Honda Giken Kogyo Kabushiki Kaisha
Nguyen Tan
LandOfFree
Mobile vehicle travel control system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Mobile vehicle travel control system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Mobile vehicle travel control system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2948714