Westinghouse Air Brake Company

David A Greer

James A Wood

David E Schweikert

Richard J Mazur

John H Corvin

An event data recorder and method for recording data relating to a distinct event which pertains to operation of a mechanism. The recorder comprises a device for collecting data pertaining to such operation and formatting such data into a sequence of data elements. A circular buffer is linked to the collecting and formatting device for temporarily storing a number of data elements. The elements are stored on the buffer as a newest element continuously writes over an oldest element as a storage limit of the buffer is reached. The recorder also includes a timer of predetermined duration which activates upon each occurrence of such event. The recorder has a memory device for retaining the data elements. The elements can be accessed therefrom for analysis of such operation of such mechanism surrounding such event. The recorder further includes a data element transfer device, connected to the timer, for transferring the elements from the buffer to the memory device wherein for each occurence of such event a preselected number of the data elements stored prior to, and including, an instant the timer deactivates is transferred by the transfer device from the buffer to the memory device. A data log is thereby formed within the memory device from which the elements may be accessed for analysis of such operation of such mechanism.

Event history data acquisition

This invention of a proportional force modulation wheel slide protection process for steel wheel/steel rail vehicles. It applies particularly to self-propelled transit type railway vehicles. It uses a slide detection logic which predicts the force reduction needed to control slippage and correct the slide condition. The force modulation is made on the basis of the initial prediction and the time that a slide has been in effect to determine if greater force reduction is needed to effect a slide correction. Sensing of positive to negative axle rate polarity shift is used to determine when a slide has been corrected and normal braking force can be restored. This process is used to control slides by modulating both the dynamic and friction braking in like manner. The normal braking control devices are used to reduce braking force during slide correction. Although this process could be implemented through the use of discrete circuits, it lends itself to microprocessor applications.

Proportional polarity shift wheel slide protection

An apparatus for providing relative spin speed traction control on a railway vehicle. Such apparatus includes a wheel spin detection device connected to receive a plurality of input signals; one of such input signals being an externally generated axle rate signal which represents an acceleration/deceleration rate of a particular wheel/axle set being monitored with respect to wheel slippage. This device generates a spin speed selection output signal and a respective axle's wheel spin detection signal. A wheel spin correction device connected to receive as input signals; a power/brake signal which represents when such vehicle is either in a braking mode or not, a spin speed selection output signal and the respective axle's wheel spin detection signal. This device determines the appropriate output force command signal selected from remove, hold and apply and also generates an output signal indicating a spin correction being in progress or not in progress for a respective axle. A wheel spin axle force command signal generating unit connected to receive a power/brake signal, an output force command signal and a signal indicative of spin correction, for generating a re-application jerk limiting output signal and communicating this signal to respective truck 1 and truck 2 propulsion control units. A speed normalization unit connected to receive raw axle speed signals, a power/brake signal, axle rate signals and an output signal representative of car level spin for generating an output signal representative of normalized axle speed.

Relative spin speed traction control

A system for controlling the operation of a door comprising a first microprocessor and a second microprocessor each having a plurality of inputs for sensing the status of a vehicle. The plurality of inputs include a no motion trainline input, an open trainline input, an unlock trainline input and a close trainline input. The first microprocessor also has a close grant input for receiving a close grant signal from the second microprocessor while the second microprocessor also has a close request input for receiving a close request signal from the first microprocessor. The system also includes a motor for opening and closing the door and a motor relay circuit device, controlled by the microprocessors, for controlling the direction of power flow through the motor. When the motor relay circuit device activates, the motor is enabled to open the door and when it deactivates the motor is enabled to close the door. The system further includes a motor chopper control for controlling the delivery of power to the motor. The motor chopper control is controlled by the microprocessors so that when the motor relay circuit device activates, the motor chopper control delivers power to the motor to open the door and when it deactivates the motor chopper control delivers power to the motor to close the door. If at least one of the microprocessors detects a system malfunction, the motor chopper control will be disabled thereby preventing power flow to the motor and operation of the door.

Embedded duplex local control panel

This invention provides method and apparatus for an improved pattern recognition wheel slide protection system for passenger transit type railway vehicles. It receives as inputs the rotational velocities of all the axles on the vehicle, and the acceleration rates for the axles. It also receives signals for brake cylinder pressure. The system uses the velocity and acceleration data to determine whether the wheels on an axle are slipping, and determines the severity of the slip. It calculates a timeout value based on the severity of the slip, and times a slip correction until the timeout value is reached, whereupon the slip correction is terminated. The system uses a simplified logic for providing brake control signals. A cascade logic method is used in which the brake control signal starts out indicating full application, then, based on signals indicating change in sign of acceleration rate, and acceleration rate in excess of a predetermined value, changes the brake control signal to pulsed brake application. Further indications based on axle velocity and acceleration cause the signal to change to a hold signal, then to a release pulse signal, and finally to a signal for release. This cascaded logic provides signals for brake valve control which have five values, APPLY, APPLY PULSE, HOLD, RELEASE PULSE, and RELEASE. Information obtained from axle rate signals is also used to specify for the RELEASE PULSE mode the duration of release and the duration of hold.

Simplified pattern recognition wheel slide protection

Method of providing brake retardation capability safety check. Method includes generating a signal representing vehicle mass, and combining it with an electric brake feedback signal and a brake cylinder pressure signal to generate a signal representing vehicle deceleration rate. Integrating the signal representing vehicle acceleration rate to generate an output signal representative of a process cycle speed reduction value. Inputting and storing values of process cycle speed reduction output signals to and in, respectively, a summation unit. Adding such values inputted to summation unit to a predetermined number of seconds worth of process cycle speed reduction values and generating output signal representative of braking effort available in terms of speed reduction over such predetermined number of seconds. Inputting brake command signal to brake command jerk limiting unit. Adding a delay value to brake command signal and jerk limiting brake command signal to provide output signal having a value equal to deceleration rate request value. Inputting deceleration rate request output signal to minimum capability level determination unit and generating output signal representative of minimum acceptable braking capability level in terms of speed reduction over predetermined number of seconds and comparing braking effort available to minimum acceptable braking capability level and determine whether minimum required safe braking level has been achieved.

Method of and an apparatus for providing a safety check of the brake

A method of and an apparatus for controlling wheel slip in a railway vehicle brake system which includes: determining whether the axle rate is in the slippage range, and generating a first output logical signal indicative thereof; comparing the axle rate and the first output logical signal to determining an energy summation value indicative of the wheel/axle set's loss of energy due to braking wheel slippage, and generating an energy summation signal indicative thereof; determining an energy loss limit and generating an energy loss limit signal at which wheel slippage has little potential for self correction; comparing the energy summation signal and the energy loss limit signal to generate a second logical output signal indicative of whether the wheel/axis set is in a slip condition that needs correction; comparing the axle rate signal, the energy summation signal and the second logical output signal to generate a wheel slip intensity signal; converting the wheel slip intensity signal to a command signal; and utilizing the command signal in a force modulation interface to vary the rate of braking force reduction.

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Simpsonville, SC, United States of America

David A Greer