Vehicle control system for multi-branching track

• US 5,329,449 A
• Filed: 10/29/1993
• Issued: 07/12/1994
• Est. Priority Date: 08/23/1990
• Status: Expired due to Fees

• Current Assignee: Daifuku Company Limited
• Original Assignee: Daifuku Company Limited
• Inventors: Watanabe, Yoshitaka, Tanizawa, Hideichi
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): LOUIS JACQUES, JACQUES H
• Application Number:
  US08/144,999
• Time in Patent Office: 256 Days
• Field of Search: 180/168, 180/169, 364/443
• US Class Current: 701/25
• CPC Class Codes: G05D 1/0261 using magnetic plots
• CPC Class Codes: G05D 1/0263 using magnetic strips
• CPC Class Codes: G05D 1/0272 comprising means for registering the travel distance, e.g. revolutions of wheels measuring distance traversed on the ground by vehicles, e.g. using odometers G01C22/00
• CPC Class Codes: G05D 1/0297 by controlling means in a control room
• CPC Class Codes: G05D 2201/0216 Vehicle for transporting goods in a warehouse, factory or similar

Abstract

A vehicle control system for a multi-branching track has a main travelling track for guiding a vehicle, a storage unit disposed before a branch point and storing data for selectively guiding the vehicle to one of a plurality of branch tracks, and a data-reading unit mounted on the vehicle and for reading the data stored at the storage unit. The storage unit stores data of branching directions of the branch tracks and further data of addresses of stations included in the respective branch tracks, with the data and further data being correlated with each other.

Claims

1. A vehicle control system for a multi-branching track, the system comprising:

a vehicle (A);

a plurality of stations (ST) at each of which said vehicle (A) is stopped;

a main travelling track (L) for guiding the vehicle (A), said track (L) including a plurality of predetermined branch points (K), across each of said branch points (K) said main travelling track being discontinuously separated by predetermined distances between an upstream line and a plurality of downstream lines, said vehicle including means for sensing said main travelling track whereby said vehicle is adapted to effect guided runs on said upstream line and said downstream lines;

a storage means (T) disposed before each said branch point (K) and storing data for selectively guiding the vehicle to one of said downstream lines;

a mark (M) provided before each said branch point (K) for accurate detection of a branching start position of the vehicle;

wherein said vehicle includes read means for reading the data stored at said storage means and a mark sensor (6) for detecting said mark (M);

wherein said data stored at said storage means (T) includes data of branching directions of said downstream lines and further data of addresses of stations included in the respective downstream lines, said data and said further data being correlated with each other; and

wherein said vehicle effects a self-contained run through said predetermined distances to switch over from said upstream line to one of said downstream lines and then switches to a guided run.

2. A system according to claim 1, wherein said storage means stores said address data, concerning the station located at said branch track after a converging point of the plurality of branch tracks, in association with branching direction data of a branch track having a shortest distance to a target station.

3. A system according to claim 1, wherein said main travelling track is constructed as an embedded laid-out magnetic structure fixedly surrounded with epoxy resin material and having a rectangular cross section, front and back faces of said magnetic structure having polarities opposite to each other.

4. A system according to claim 3, wherein a mark is provided at each station for accurate detection of a branching start position or a stop position of the vehicle.

5. A system according to claim 1, wherein said mark comprises a magnetic element embedded in the vehicle travelling surface, said element having opposite polarities at front and back faces thereof.

6. A system according to claim 1, wherein said vehicle further includes;

a driving-steering wheel drivable by a propelling motor and steerable by a steering motor,

a driven wheel,

a magnetic sensor for detecting said track and obtaining therefrom data vehicle steering control,

a mark sensor for detecting said mark, and

a communication unit for communicating with said stations.

7. A system according to claim 1, wherein a mark is provided as a reference point utilized by the vehicle in switching over to said self-contained run after reading the stored data from said storage means, said vehicle including a mark sensor for detecting said mark, said data stored at said storage means including at least data concerning a distance from said mark to a point where the vehicle is to be switched over to said self-contained run.

8. A system according to claim 1, further comprising:

a stop control device for causing said vehicle guided along said main track to effect gradual speed reduction to reach a predetermined reduced speed before the predetermined stop position and then to cause said vehicle to stop at said predetermined stop position.

9. A system according to claim 8, wherein a data-writable storage means and a mark indicating a reference point are provided with a predetermined distance therebetween in the mentioned order from an upstream side relative to a travelling direction of said vehicle before said predetermined stop position;

said storage means storing at least data concerning a distance from said mark to said stop position;

said vehicle including;

a read means for reading the stored data of said storage means,

a mark sensor for detecting said mark,

a travelling distance measuring means,

a speed reduction device for reducing a travelling speed of the vehicle to a predetermined reduced speed, and

a control device for calculating, based on said distance data, said travelling distance from said mark and said predetermined reduced speed, a point for the vehicle to initiate speed reduction so that the vehicle achieves said predetermined reduced speed immediately before said predetermined stop position, said control device actuating said speed reduction device at said speed-reduction initiating point.

10. A system according to claim 9, wherein said vehicle includes a speed detecting means for detecting a travelling speed of the vehicle, said control device calculating said speed-reduction initiating point, based also on travelling speed data obtained by said speed detecting means.

11. A system according to claim 1, wherein a control mechanism is provided for preventing a subsequent vehicle from entering a predetermined zone within the vehicle travelling passage when said foregoing vehicle stays within said zone.

12. A system according to claim 11, wherein said control mechanism including;

a detecting means for detecting passage of a vehicle and storing the detection data without power supply,

an electric-powered release means for releasing, with electric power supply, the stored data at said detecting means,

a transmission coil for transmitting said stored data of said detecting means.

said detecting means, said electric-powered release means and said transmission coil being provided at a starting end of said predetermined zone,

a power-receiving coil provided at a terminal end of said zone for receiving the electric power to be supplied to said releasing means,

said vehicle including;

a detected member to be detected by said detecting means,

an electromagnetic coupling type data transmission means for supplying the power through an electromagnetic coupling with said power-receiving coil, and

a travelling control means for controlling travelling of said vehicle,

said travelling control means being so constructed as to stop said subsequent vehicle when said data transmission means detects the data indicating presence of said foregoing vehicle and to allow said subsequent vehicle to enter said predetermined zone when said data transmission means detects absence of said foregoing vehicle within said predetermined zone.

13. A system according to claim 1, wherein said travelling control data further includes data concerning a turning radius, a turning speed and a travelling speed after the vehicle has switched over to one of the branch tracks.

14. A vehicle control system as claimed in claim 1,

wherein said travelling control data includes at least concerning a distance from said mark to a point where the vehicle is to be switched over to said self-contained run;

and

wherein said vehicle further includes a magnetic sensor (5) including a number of magnetic sensing elements provided in said vehicle for sensing magnetism from the main travelling track, thereby to guide said vehicle to a proper position with respect to the travelling track.

15. A vehicle control system for a multi-branching track, the system comprising:

a vehicle (A);

a plurality of stations (ST) at each of which said vehicle (A) is stopped;

a main travelling track (L) discontinuously separated at predetermined positions (K) by predetermined distances between an upstream line (L1) and a plurality of downstream lines (L2), (L3);

a first mark (M1) provided before each said branch point (K) for accurate detection of a branching start position of the vehicle;

a second mark (M2) provided at each said station (ST) for accurate detection of a stop position of the vehicle;

a first storage means (T1) disposed before each said branch point (K) and storing data for selectively guiding the vehicle to any of the branch tracks (L1) , (L2) , (L3) , travelling control data for allowing said vehicle (A) to effect a self-contained run at each said branch point (K), and address data concerning addresses of stations included in the respective branch tracks;

a second storage means (T2) disposed before each said station (ST) and storing data at least concerning a distance from said first mark (M1) to said stop position;

said vehicle further including a magnetic sensor (5) for sensing said main travelling track (L);

a mark sensor (6) for sensing said first and second marks (M1), (M2);

a read means (7) for reading the data stored respectively at said first storage means (T1) and said second storage means (T2);

a control unit (9) for causing the vehicle (A) to effect said self-contained run or to make a stop at one of said stations (ST) based on information obtained from said read means (7) and said mark sensor (6),

wherein said first storage means (T1) stores address data concerning addresses of stations included in the travelling track after the plurality of branch tracks join together, thereby to determine a proper branch track through which the vehicle reaches each said station (ST) by the shortest distance;

wherein said vehicle (A) detects said first mark (M1) by said mark sensor (6) and travels by a predetermined distance from said first mark (M1) and then effects said self-contained run over the section discontinuously separated by predetermined distances in accordance with said travelling control data stored at said first storage means (T1), thereby to switch over from said upstream line (L1) to one of said downstream lines (L2), (L3);

wherein said travelling control data includes data at least concerning a distance from said first mark (M1) to a point where the vehicle is to be switched over to said self-contained run; and

wherein said magnetic sensor (5) includes a number of magnetic sensing elements provided in said vehicle (A) to sense magnetism from said main travelling track (L), thereby to guide said vehicle (A) to a proper position with respect to said main travelling track (L).

16. A vehicle control system for a multi-branching track, the system comprising:

a main travelling track (L) for guiding a vehicle (A), said main travelling track including, at predetermined positions (K), (J), (C), upstream lines and downstream lines with the upstream lines being discontinuously separated by predetermined distances from the downstream lines, such that said vehicle effects a self-contained run through the predetermined distances according to predetermined travelling control data to switch over from one of said upstream lines to one of said downstream lines;

a storage means (T) disposed before a branch point and storing data for selectively guiding the vehicle to one or a plurality of branch tracks;

a read means (7) mounted on the vehicle (A) and for reading the data stored at said storage means, wherein said storage means (T) stores data of branching directions of the branch tracks and further data of addresses of stations included in the respective branch tracks, said data and further data being correlated with each other;

a further storage means provided before each said predetermined positions (K), (J), (C), said further storage means storing data for said self-contained vehicle run;

a mark (M) provided as a reference point utilized by the vehicle in switching over to said self-contained run after reading the stored data at said storage means, said vehicle including a mark sensor (6) for detecting said mark (M), said travelling control data stored at said storage means (T) including data at least concerning a distance from said mark (M) to a point where the vehicle is to be switched over to said self-contained run; and

a magnetic sensor (5) including a number of magnetic sensing elements provided in the vehicle (A) to sense magnetism from said main travelling track (L), thereby to guide said vehicle (A) to a proper position with respect to said travelling track (L).

17. A vehicle control system for a multi-branching track, the system comprising:

a vehicle (A);

a plurality of stations (ST) at each of which said vehicle (A) is stopped;

a main travelling track (L) for guiding the vehicle (A), said track (L) including a plurality of predetermined branch points (K), across each of said branch points (K) said main travelling track being discontinuously separated by predetermined distances between an upstream line (L1) and a plurality of downstream lines (L2), (L3);

a storage means (T) disposed before each said branch point (K) and storing data for selectively guiding the vehicle to one of a plurality of branch tracks (L1), (L2), (L3);

a mark (M) provided before each said branch point (K) for accurate detection of a branching start position of the vehicle;

wherein said vehicle includes read means for reading the data stored at said storage means and a mark sensor (6) for detecting said mark (M);

wherein said data stored at said storage means (T) includes data of branching directions of said branch tracks (L1), (L2), (L3) and further data of addresses of stations included in the respective branch tracks (L1), (L2), (L3), said data and said further data being correlated with each other;

wherein said vehicle effects a self-contained run through said predetermined distances to switch over from said upstream line (L1) to one of said downstream lines (L2), (L3);

wherein said travelling control data includes at least concerning a distance from said mark to a point where the vehicle is to be switched over to said self-contained run; and

wherein said vehicle further includes a magnetic sensor (5) including a number of magnetic sensing elements provided in the vehicle for sensing magnetism from the main travelling track, thereby to guide said vehicle to a proper position with respect to the travelling track.