Abstract:
An energy storage wheel spin propulsion control system for detecting and correcting a spinning wheel situation so that the maximum available adhesion is utilized to the fullest extent in accelerating a railway vehicle while at the same time maximizing the use of the available processing time to permit an appropriate amount of time for diagnostic purposes. The primary data used to form the logic inputs is derived from the axle rate signals which are fed to spin energy storage value threshold and difference comparison sensors. The spin energy storage value and difference comparison sensors supply logical inputs in spin energy threshold, dissipation threshold and optimization threshold sensors and spin rate difference sum sensor, respectively, which, in turn, supply logic inputs to spin enable timer and spin enable sensors and a spin control logic output sensor. A slip-spin output determination sensor receives logic signals from a power-brake signal circuit and command signal from the spin control logic outer sensor and a slip interface circuit to cause the production of a full requested, reduce and/or hold tractive effort command.
Abstract:
An electronic load weigh device is used with a railcar truck control unit. A relay valve provides to a brake cylinder a pressure proportional to the pressure impinging upon its control port. A first feedback signal is indicative of the pressure at the control port. A second feedback signal is indicative of the load borne by the truck. A pressure switch opens when pressure within a trainline changes to a level indicative of an emergency. By controlling the opening and closing of application and release magnet valves, a controller controls the pressure impinging on the control port and thereby service braking of the wheels of the truck. The load weigh device includes (i) circuitry for electronically compensating for the load during braking and (ii) a mechanism for granting the circuitry exclusive control over the magnet valves. Should such emergency occur, the mechanism responds to such emergency by disconnecting the controller from the magnet valves. This gives the circuitry exclusive control over the magnet valves. The circuitry compensates for the load borne by the truck during emergency braking by selectively opening and closing the magnet valves, according to predetermined criteria using the feedback signals, thereby controlling the magnitude of the pressure impinging upon the control port. Absent such emergency, the mechanism responds to such absence by connecting the controller to the magnet valves whereby such service braking on the truck is normally controlled, yet the circuitry is still enabled to compensate for the load during such service braking.
Abstract:
A synchronous wheel-slip control system for a multi-axle vehicle having a speed sensor for producing signals representative of the velocity of each of the wheel axle units. A differentiator connected to each of the speed sensors for differentiating the velocity signals to obtain rate signals. A plurality of truck and car rate comparators for determining when all the wheel axle units are in synchronism. A plurality of truck and car highest velocity circuits for determining the actual highest velocity signal of the wheel axle units and a car differentiator for differentiating the actual highest velocity signal to obtain the actual highest rate signal. A synchronous slip logic network for causing a data processing circuit to initiate a brake force reduction action of one of the trucks when all the wheel axle units are in synchronism and when the actual highest rate signal exceeds a requested rate.
Abstract:
A digital multi-point electronic load weigh system is used with a railcar truck control unit to provide a digital all electrical/electronic system, which will perform the brake load weigh function for an electro-pneumatic brake system. The digital multi-point electronic load weigh system is primarily to be used with a distributed electronic control system using neuron style communication/control microprocessors. However, the digital multi-point electronic load weigh system can also be integrated with existing electro-pneumatic brake control components.
Abstract:
An electronic load weigh device is used with a railcar truck control unit. A relay valve provides to a brake cylinder a pressure proportional to the pressure impinging upon its control port. A first feedback signal is indicative of the pressure at the control port. A second feedback signal is indicative of the load borne by the truck. A pressure switch opens when pressure within a trainline changes to a level indicative of an emergency. By controlling the opening and closing of application and release magnet valves, a controller controls the pressure impinging on the control port and thereby service braking of the wheels of the truck. The load weigh device includes (i) circuitry for electronically compensating for the load during braking and (ii) a mechanism for granting the circuitry exclusive control over the magnet valves. Should such emergency occur, the mechanism responds to such emergency by disconnecting the controller from the magnet valves. This gives the circuitry exclusive control over the magnet valves. The circuitry compensates for the load borne by the truck during emergency braking by selectively opening and closing the magnet valves, according to predetermined criteria using the feedback signals, thereby controlling the magnitude of the pressure impinging upon the control port. Absent such emergency, the mechanism responds to such absence by connecting the controller to the magnet valves whereby such service braking on the truck is normally controlled, yet the circuitry is still enabled to compensate for the load during such service braking.
Abstract:
A control unit includes several magnet and air piloted valves, a transducer, a transmitter, a pressure switch and a pipe network. Controlled by a central controller, the apply and release valves allow a first trainline to charge the pipe network or vent to atmosphere whereas the emergency release valve can vent a second trainline to atmosphere. The transfer valve connects the first trainline to a command port of the control unit unless its pilot port receives an emergency braking request in which case it connects the pipe network to the command port. The transducer converts pressure in the first trainline to an electrical signal. The transmitter conveys this signal to a control bus. The pressure switch closes if the second trainline charges to a preset pressure. Upon closure of the pressure switch and a command from the controller, the charging valve allows the pipe network to charge the second trainline to a threshold level. The maintaining valve permits the pipe network to charge the second trainline unless pressure at its pilot port falls below the threshold. The regulating valve regulates air from a primary port of the control unit for use in the pipe network. The pipe network allows the apply valve, the first trainline and the regulating valve to supply air to the transfer valve, charging valve, maintaining valve and a master port of the control unit. When pressure in the second trainline drops faster than a predetermined rate, the vent valve vents the second trainline to atmosphere.
Abstract:
A pneumatic trainline control unit receives air from a first pneumatic trainline which it uses to charge and maintain pressure in a second pneumatic trainline. It also provides brake control pressure to a universal pneumatic brake unit on a rail vehicle upon receiving an emergency braking request from the second trainline. The pneumatic trainline control unit includes an air piloted transfer valve, an air piloted maintaining valve, a charging magnet valve, an emergency release magnet valve, a low pressure switch, an air piloted vent valve and a pipe network. The pipe network allows the first trainline to supply air to the transfer valve, the charging valve and the maintaining valve. The transfer valve features a transfer pilot port. It connects a command port of the pneumatic trainline control unit to atmosphere unless its transfer pilot port receives the emergency braking request in which case it connects the pipe network to the command port. The low pressure switch closes if the second trainline charges to a preset pressure. Upon closure of the pressure switch and a manually initiated command from the controller, the charging valve allows the pipe network to charge the second trainline to a minimum threshold level. The maintaining valve features a main pilot port. It permits the pipe network to keep the second trainline charged unless pressure at its main pilot port falls below the minimum threshold. When pressure in the second trainline drops faster than a predetermined rate, the vent valve vents the second trainline to atmosphere.
Abstract:
A brake pipe sensing unit may be used with a universal pneumatic brake control unit of a rail vehicle. The brake pipe sensing unit includes a control reservoir, an auxiliary reservoir, a three state valve, a quick service valve, a brake pipe transducer and a transmission device. The control reservoir is used as a volume in which gas under pressure may stored and from which gas under pressure may be supplied. The auxiliary reservoir communicates with a supply port of the universal unit and with a first and a second route of the brake pipe sensing unit. The three state valve has a first pilot port in communication with a brake pipe of the rail vehicle, a second pilot port in communication with the control reservoir, and first and second exhaust ports both of which connect to atmosphere. The three state valve operates in an apply position, a release position and a lap position depending on the pressure bearing on the first and second pilot ports. The quick service valve connects within the first route and has a service pilot port in communication with both the auxiliary reservoir and the supply port. The quick service valve closes the first route when pressure at the service pilot port exceeds a preselected level. The brake pipe transducer converts pressure within the brake pipe to an electrical signal. The transmission device communicates the electrical signal received from the brake pipe transducer to a brake control bus on the rail vehicle.
Abstract:
An electronic slip control system for railway vehicle brakes having a standard slip control logic circuit responsive to axle speed and rate signals to produce a multi-bit binary number word. A primary slip control word formation circuit for converting the multi-bit binary number word to a hexidecimal number word which is conveyed to a primary slip control table. The primary slip control table circuit conveys the hexidecimal number word to a table output selection circuit. A synchronous slip control logic circuit responsive to the axle speed and rate signals to produce a multi-bit binary word. A synchronous slip control word formation circuit for converting the multi-bit binary number word to a hexidecimal number word which is conveyed to a synchronous slip control table circuit. The synchronous slip control table circuit conveys the hexidecimal number word to the table output selection circuit which causes intermediate circuit means to convey an appropriate control signal to a brake valve for preventing wheel lockup.
Abstract:
An electropneumatic brake system for a railway vehicle having an electronic control unit that outputs a friction brake demand signal according to the difference between a brake command signal and a feedback signal representative of the effective dynamic brake, whereby the total dynamic and friction brake effort corresponds to the brake command signal. The brake system also includes a pneumatic operating unit having a pair of high-capacity, electropneumatic valves operated by the friction brake demand signal to regulate the pneumatic pressure at the brake unit directly, that is, without an intermediary relay valve. Such an arrangement provides better response and more accurate pressure feedback of the friction brake level to the electronic control unit. A service rate control choke is located ahead of the electropneumatic valves, which allows these valves to perform the emergency and wheel-slip control functions without requiring independent valves for this purpose, by virtue of their high-capacity capability.