Vehicle Control System

Abstract

The control system governs the operation of a vehicle along the right-of-way which is divided into a plurality of zones and has control means for governing safe operation of the vehicles in accordance with traffic conditions. The improvement comprises means on the vehicle for demarcating the ends thereof and wayside located check-in means at entering boundaries of each zone responsive to the passage of the front end of the vehicle which provides the check-in signal. Wayside located check-out means beyond the check-in means at exit boundaries of each zone providing an overlap zone between zone boundaries, and is responsive to the passage of the rear end of the vehicle. The check-in marker provides the check-out signal while clearing the previous zone only provided the check-in signal is received. A speed selector is located in the overlap zone enabled by the check-in signal for communicating a selected speed limit to the vehicle only within each of said overlap zones.

Description

BACKGROUND OF INVENTION

The control system provided herein is operative to govern the automatic operation of one of the newer types of guided vehicles but may be applied to any railroad or street vehicle.

For certain applications a block signaling system is rather effective to control the operation of railroad or other similar vehicles, utilizing coded track circuits, radio remote control, periodic inductive coupling, or wiggle wire transmission along the rails or guideway. Many of these systems provide continuous control while others, like the periodic inductive coupling, provide intermittent control for checking. For such systems, block sections may be relatively short, and require complex apparatus to assure that a vehicle is where it must be for purposes of safety. Further, speed checks must be maintained in order to assure that the vehicle is not running beyond maximum speed limits provided for each section.

It is necessary in many instances to include short blocks or zones in areas near station platforms or where traffic is heavy and headway requirements are short. However, in those areas where those requirements are not so strict, for example, on express lines between distant station locations, long blocks are preferable. The system of course must be designed to operate in safe failure modes. However, the requirements for wayside located control and checking apparatus at frequent intervals may be costly and unnecessary.

It is therefore an object of the present invention to provide a system which obviates one or more of the disadvantages of the described prior arrangements.

It is also an object of the present invention to provide a system for automatic control of a vehicle with infrequent and relatively long wayside control and check locations.

SUMMARY OF INVENTION

There has been provided a control system which governs the operation of a vehicle along the right-of-way which is divided into a plurality of zones and has control means for governing safe operation of vehicles in accordance with traffic conditions. The improvement comprises means on the vehicle for demarcating its ends and wayside located check-in means at an entering boundary of each zone responsive to the passage of the front end of the vehicle for providing a check-in signal. Wayside located check-out means is placed beyond each of said check-in means at an exit boundary of each zone for providing an overlap zone between zone boundaries and is responsive to the passage of the rear end of the vehicle and the check-in means for the advance block for providing a check-out signal, and for clearing the previous zone only provided the check-in signal is received. A speed selector means is located in the overlap zone and is enabled by the check-in signal for communicating a selected speed limit signal to the vehicle only within each of said overlap zones within the right-of-way.

For a better understanding of the present invention, together with other and further objects thereof, reference is directed to the following description taken in connection with the accompanying drawings, while its scope will be pointed out in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing of the system contemplated in the present invention.

FIG. 2 is a block diagram showing vehicle carried equipment and controls.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the present disclosure a vehicle V is proposed which rides in a guideway GW including a linear induction motor rail. The system may, of course, be a railroad or rubber-tired vehicle. In this embodiment, an air cushion vehicle is contemplated; however, the principles involved in control of the vehicle V would apply to any convenient guideway system. The guideway GW is divided into blocks or zones and a section thereof is shown including blocks A, B and C. Each alternate block in this case, blocks A and C, have a code marker noted code 1 impressed upon the rail of the guideway GW. This code is some sort of periodic inert marker as perhaps a paint strip or indentations on the guideway rail GW. A code 2 for block B as an alternate block is also provided, and the vehicle has apparatus for sensing the codes 1 and 2 and alternately switching the response characteristics to the code available in accordance with other restraints on the system. One reason for using two codes would permit checking of the progress of the vehicle in a dynamic manner.

It should be noted in the diagram of FIG. 1 that blocks A, B and C overlap, that is, the check-out for block A is beyond the check-in for block B. The vehicle V has check-in and check-out transmitters respectively labelled 4 and 6 which cooperate with check-in and check-out receivers 10 and 12 adjacent to the guideway GW. As the front of the vehicle approaches check-in marker 10, the check-in transmitter 4 provides a signal to junction box 14 associated therewith. In this case, the vehicle V is in block A in approach of block B. As the vehicle checks into block B, a signal is provided at junction box 14 to loop 8 for providing a maximum speed limit coded signal which is received on the vehicle. This speed limit signal may be exceeded if the vehicle is braking sufficiently to insure a safe speed at the exit of block B. As the rear of the vehicle carrying check-out transmitter 6 passes check-out receiver 12, a signal is provided to junction box 14 for clearing occupancy of block A. However, occupancy of block A cannot be cleared unless block B is set at occupied. Therefore, a failure of either wayside receiver 10 or 12, prevents the preceding block; namely A, to be set clear which, of course, maintains protection of the vehicle V from the rear.

Vehicles measure their own speed in this system by sensing the uniform code patterns 1 and 2 impressed along the guideway GW. The vehicle has means for generating a signal in accordance with the passage of each of the impressions which make up the respective codes and the frequency of this signal is a direct indication of the actual speed. It should be noted that the junction boxes 14 are coupled by a code transmission line C1 and also by that same line to a central control computer 16. Thus, by using coded transmission, signals may be transmitted along the entire route from a central control location. This may be a two-wire system as shown in the drawing, or more if necessary, however, it is contemplated that a simple yet effective code communication be established in order to avoid the frequent use of junction boxes and associated circuitry along the guideway route.

FIG. 2 illustrates apparatus necessary for controlling the vehicle V in accordance with signals from the wayside loop 8 and the code markers 1 and 2 shown in FIG. 1. A guideway code reader 20 is installed on the vehicle V which is operative to read either of the codes 1 or 2 and provide a signal through a code switch 26 to speed sensor 24. The code switch provides a signal to the speed sensor over inputs 1 or 2 as shown in the drawing, if it is receiving one of the codes, and the code switch 26 is activated for that code reception. The speed sensor 24 provides an input to motion detector 30 which is utilized for checking purposes as later described in the disclosure. An output of the motion detector 30 indicative of the vehicle speed is impressed on an input of governor 32 which may be one of many types now utilized in the art to hold off application of an emergency brake control 36. A similar input is also provided to speed regulator 34 which controls the service brake unit 38 and a propulsion unit 40 which in this case is the linear induction motor. The speed regulator 34 also receives an input from a receiver and decoder 22 which is coupled to an external antenna 18. The antenna picks up a signal from the wayside loop 8 as it passes the overlap zone described with respect to FIG. 1 and transmits a signal to the governor 32 and the speed regulator 34. The governor compares the coded input from the motion detector 30 with the input from the decoder 22 and holds off emergency brake application if the actual speed does not exceed the speed limit as provided by the output from the wayside loop. Similarly, the speed regulator controls the propulsion and service braking of the vehicle V in accordance with the actual speed signal and the maximum speed limit signal. A jerk control 44 provides a signal to the propulsion system 40 and the service brake unit 38 for limiting the rate of start-up and brake applications in order to provide a more comfortable ride for passengers on the vehicle. The jerk control is also responsive to the speed regulator which provides an indication of vehicle operation in order to correct the output of jerk control 44 for different vehicle speeds.

An accelerometer 50 provides inputs to the governor 32 the speed regulator 34 in order to respectively delay emergency brake applications if the vehicle is decelerating at a proper rate after a speed limit change and also to provide an acceleration signal to the speed regulator 34 in order to regulate more smoothly the service and propulsion system operations.

A loop detector 28 is responsive to signals transmitted by the wayside located transmitting loops 8 and provides an input to code switch 26 each time a loop is sensed. This input initiates a switch from one code to another because each time a loop is inserted, the code on the guideway GW is changed and it enables the speed sensor 24 to respond to the appropriate code impressed on the guideway GW. For example, if a malfunction occurs the system whereby the code switch is inoperative, no code may be received by the sensor 24 and thus a signal must be initiated for applying the emergency brakes. So, not only must a code along the guideway be sensed by the code receiver 20, but the code switch 26 must provide indication to speed sensor 24 that this is a proper code for the block that the vehicle occupies.

A profile generator 33 provides an input to the speed regulator 34 in response to an input from the wayside loop 8 for governing the operation of the vehicle V along the specific route or within a specific block, and in fact, may vary the optimum speed of the vehicle as it proceeds through a block. This may be pre-programmed in accordance with anticipated operating conditions along the right-of-way when the system is initially set up.

The on-board profile generator 33 is also called into action when activated by wayside markers 64 located at station stops for regulating a precision stop. Registration of the vehicle in the proper location is verified before the leveller 48 and doors are permitted to be operated.

The loop detector 28 also couples a signal to door control 46 during station stopping to indicate that the signal has been received from the wayside marker 64 and that the vehicle is properly located at the desired location. The door control 46 receives an additional input from the receiver and decoder 32 which is coupled over the wayside loop 8 from the junction box 14 for initiating a door open command. An input from the motion detector 30 insures the door control 46 that the vehicle is not registering speed, and a brake sensor 42 responsive to the service brake apparatus 38 provides a signal to assure the door control that the brakes are applied to a proper operating pressure. A leveller apparatus 48 is actuated in accordance with signals from the receiver 22, brake sensor 42 and motion detector 30 to remove levitation of the vehicle upon command from the decoder 22 when proper brake assurance is provided. When the leveller 48 has completed its sequence, it initiates the final signal necessary to operate the doors by completing the inputs to the door control 46.

The brake sensor 42 has an additional function to provide a delay in the operation of the governor 32 such that if the vehicle temporarily exceeds the maximum speed limit that is communicated over the loop 8 the emergency brake application will be delayed as long as sufficient brake application exists to slow the vehicle down within the blocks. This delay assures that unnecessary emergency brake applications are avoided whenever possible.

It is imperative to know what speed command a vehicle receives from the wayside loop 8 at the overlap. When the vehicle enters the overlap zone, it receives a signal from the wayside loop through the antenna 18 to loop detector 28. This signal, however, is conditioned so that it is transmitted by the wayside loop only after the vehicle has caused the block in advance to show occupancy. Failure of the vehicle to switch the pattern of code switch 26 over loop detector 28 either as a result of the failure to check into the advanced block or because of a failure to receive the signal on board the vehicle results in the vehicle losing the code pattern 1 or 2. Under these conditions, therefore, a failure of the vehicle to receive both the speed limit signal from the loop 8 or the coded signal from the code reader 20 results in a malfunction condition whereby a mandatory emergency braking is initiated.

When the vehicle moves into the advance block sufficiently such that its rear passes over the check-out receiver 12, check-out transmitter provides a signal to initiate activation of a clear signal for the preceding block. Once the vehicle has been enabled to receive the selected code present on the rail GW, the vehicle propulsion system and service braking 30 and 48, respectively, are operative to govern the vehicle speed until it reaches the next overlap zone. The speed limit of a zone that the vehicle occupies is such, that the following vehicle arrives at the overlap zone at a speed from which it can stop within that overlap. The length of the overlap is selected to accommodate the maximum speed selected for the preceding block. Upon entering an overlap zone for a block occupied in advance of a following vehicle, the vehicle receives a ZERO speed limit command and is required to stop within the overlap, so that it may be in a position to receive a new speed signal when the advance block becomes clear.

A two-way radio is provided for transmission over antenna 60 for linking the control center 16 with each vehicle. Information from a recorder 15 may also be transmitted over the radio 52 for providing information as to the operation of certain vehicle systems which may be critical to the safety of the operation of the transit operation in general. Further, the signal transmitted to the control center is analyzed and a permanent record is generated in the form of a printed format.

While there has been described what at present is considered to be the preferred embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is therefore aimed in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Claims

We claim:

1. A control system for governing the operation of a vehicle along a right-of-way divided into a plurality of zones and having control means for governing safe operation of vehicles in accordance with traffic conditions wherein the improvement comprises:

a. means on the vehicle for demarcating the ends thereof;

b. an overlap zone located in the ends of each zone and formed by adjacent zones overlapping one another, wherein the boundaries of said overlap zone are defined by the boundaries of the adjacent zones;

c. wayside located check-in means at an entering boundary of each zone and its corresponding overlap zone, said check-in means responsive to the passage of the front end of the vehicle for providing a check-in signal;

d. wayside located check-out means beyond each of said check-in means and at an exit boundary of each zone and its corresponding overlap zone, said check-out means responsive to the passage of the rear end of the vehicle and the check-in means for the advance block for providing a check-out signal, and for clearing the previous zone only provided the check-in signal is received at the wayside

e. speed selector means located in said overlap zone enabled by said check-in signal for communicating a selected speed limit signal to the vehicle only within each of said overlap zones along the right-of-way; and

f. said speed selector means including a wayside loop for transmitting the selected speed limit signals only when the vehicle is in said overlap zones, and receiver means on the vehicle responsive for providing governing signals in accordance with said selected speed limit signals only until the next succeeding overlap zone.

2. The control system according to claim 1 further including inactive demarcating means located periodically along the right-of-way establishing an indication of displacement as the vehicle progresses and means on the vehicle responsive to said de-marcating means for providing an output each time the demarcating means is sensed with respect to time thereby providing a sequence of signals representative of vehicle speed.

3. The control system according to claim 2 wherein said demarcating means comprises:

first and second sets of markers located along the right-of-way having a distinctive code frequency of occurrence for each alternate zone for establishing alternating sets of control markers as the vehicle progresses from one zone to the next.

4. The control system according to claim 3 including: reader means responsive to each of said first and said second sets of markers for conditioning the receiver response, to each alternate code frequency; and means responsive to said reader means and said wayside loop for providing a signal indicative of malfunction unless the speed selection signals are received and the reader means conditions said receiver, whereby the vehicle may proceed from one overlap zone to the next without wayside control except in said overlap zones.

5. The control system according to claim 2 wherein said means on the vehicle responsive to said demarcating means comprises a speed sensor for providing said signals representative of vehicle speed and speed regulator means controlled in accordance with the speed limit signals and the speed sensor signals for providing a control output for governing vehicle propulsion.

6. The control system according to claim 5 further including: a motion detector responsive to the output of the speed sensor for providing outputs when the vehicle is in motion and a brake sensor means responsive to the condition of vehicle brake parameters for providing an output indicative thereof and door control means on the vehicle responsive to the brake sensor means, the motion detector, and the control signals from the wayside at selected overlap zones for governing the operation of the doors on the vehicle.

7. The control system according to claim 6 further including: leveller means for governing the vertical position of the vehicle relative to the right of way responsive to said brake sensor, motion detector and control signals from the wayside at said selected overlap zones, and said leveller provides a further output for controlling said door control means.

8. The control system according to claim 5 further including: inactive wayside marker means for providing indication when sensed of selected stopping locations for the vehicle and profile generator means responsive to said wayside markers for providing an input to the speed regulator for modifying the output thereof for a control precision stop.