Running control system for conveyor cart

• US 4,817,750 A
• Filed: 05/04/1987
• Issued: 04/04/1989
• Est. Priority Date: 05/09/1986
• Status: Expired due to Term

• Current Assignee: Daifuku Company Limited
• Original Assignee: 501 Daifuku Company Limited
• Inventors: Moriya, Susumu, Shimokata, Hiroshi, Taya, Takuo, Ishida, Hideo
• Primary Examiner(s): Mitchell, David M.
• Application Number:
  US07/046,871
• Time in Patent Office: 701 Days
• Field of Search: 180/167, 180/168, 180/169, 318/587, 340/905, 340/908, 364/424, 364/447
• US Class Current: 180/168
• CPC Class Codes: G05D 1/0263 using magnetic strips

Abstract

A control system for enabling a conveyor cart or carts to run automatically along a running track. The or each cart comprises a sensor for detecting a guiding line extending along the running track and outputting detection data, and a steering control device operable in response to the detection data for steering the conveyor cart to follow the guiding line. The sensor is switchable for selectively detecting right and left edges of the guiding line. The right edge is detected for permitting the cart to run through a junction along a rightwardly curved branching or merging line. The left edge is detected for permitting the cart to run through a junction along a leftwardly curved branching or merging line.

Claims

1. A vehicle running control system comprising a guiding line (L) extending along a running track, and a conveyor cart (A), the conveyor cart (A) including detecting means (6) for detecting the guiding line (L) and outputting detection data and steering control means operable in response to the detection data for permitting the conveyor cart (A) to automatically run along the guiding line (L), said detecting means (6) is switchable for selectively detecting right and left edges of said guiding line (L) wherein said detecting means (6) includes a plurality of resistances (R) connected in series and a plurality of magnetism sensitive elements operable to connect connection points of said resistances (R) to a common electric potential and said guiding line (L) comprises a magnetic tape.

2. A vehicle running control system as claimed in claim 1 wherein said guiding line (L) includes a priority line (La) and a non-priority line (Lb) merging with said priority line (La) such that said conveyor cart (A) running along said priority line (La) is caused to run with priority over another conveyor cart (A) running on said non-priority line (Lb), and wherein said conveyor cart (A) includes priority signal emitting means (11) for emitting a priority signal (P) to said another conveyor cart (A) to indicate a priority running state, receiving means (12) for receiving the priority signal (P) and stopping control means for causing said conveyor cart (A) to make an emergency stop when said conveyor cart (A) is running on said non-priority line (Lb) and said receiving means (12) receives said priority signal (P), and wherein said vehicle running control system further comprises deceleration control means for decelerating said conveyor cart (A) on said non-priority line (Lb) and when said conveyor cart (A) on said non-priority line (Lb) arrives at a position short of a point at which said nonpriority line (Lb) merges with said priority line (La), thereafter said conveyor cart (A) being stoppable by said stopping control means for an emergency stop.

3. A vehicle running control system as claimed in claim 1 wherein said guiding line (L) defines a sensor actuating area transversely of the conveyor cart (A) to be detected by said detecting means (6) mounted on the conveyor cart (A), and said steering control means is operable in response to the detection data provided by said detecting means (6) to cause a boundary (K) between a sensing range (a) of said detecting means (6) which has detected said sensor actuating area and a non-sensing range (b) thereof to approach a preset reference position (SK), said system further comprising reference position setting means (101) for setting said reference position (SK) in accordance with a width of said sensing range (a) so that said boundary (K) coincides with said reference position (SK) when the conveyor cart (A) is in a proper position relative to said guiding line (L).

4. A vehicle running control system as claimed in claim 1, wherein said magnetism detecting means (6) further includes switch means (SW) for selecting one of opposite ends of said resistances (R) to detect a resistance value with respect to said common electric potential.

5. A vehicle running control system as claimed in claim 4 wherein said resistances (R) are arranged such that said resistance value detected remains the same when directions for detecting said resistance value are switched by said switch means (SW) with the conveyor cart (A) maintained in the proper position relative to the guiding line (L), and wherein said steering control means is operable to cause a difference between a preset reference resistance value and the resistance value detected by said magnetism detecting means (6) to approach zero.

6. A vehicle running control system as claimed in claim 4 further comprising control marks (m) disposed alongside said guiding line (L), each of said control marks (m) including a plurality of magnetic pieces (m1-m6) having magnetic poles combined to provide control data for controlling said conveyor cart (A), and a trigger magnetic piece (mT) having a magnetic pole opposite to a magnetic pole of said guiding line (L) for indicating a read position of said control marks (m).

7. A vehicle running control system as claimed in claim 6 wherein said magnetic pieces (m1-m6) are arranged longitudinally of said conveyor cart (A).

8. A vehicle running control system as claimed in claim 7 wherein said magnetic pieces (m1-m6) are arranged transversely of said conveyor cart (A).

9. A vehicle running control system as claimed in claim 4 wherein said magnetic tape includes a non-magnetic protective layer (15) placed on an upper surface thereof.

10. A vehicle running control system as claimed in claim 9 wherein said non-magnetic protective layer (15) is formed of a resin.