Patent Description:
The functionality of railcar brake systems and their individual components currently is monitored through a combination of manual tests and inspections. The tests and inspections typically are performed at pre-determined time intervals; during regular scheduled maintenance; prior to a departure from the rail yard; during intermediate stops; prior to leaving the train unattended; and at other times. While vitally important to safe operation, the various brake systems tests and inspections can significantly reduce the efficiency of railroad operations, and can require a substantial expenditure of manpower.

For example, federal regulations require that single car air brake tests (SCABTs) be performed on individual railcars under certain circumstances, such as the discovery of wheel defects, after replacement of certain brake-system components, at predetermined time intervals, etc. Because SCABTs do not have a high degree of reliability, and the majority of such tests do not find identify anything wrong with the railcar, substantial amounts of time and money are wasted looking for brake issues on individual railcars.

As another example of railcar brake testing, railroad operators may spend up to three hours preparing a train for departure. The preparation process includes a Class 1A brake test-initial terminal inspection. This particular test is labor-intensive, and requires leak testing, actuation of the brakes, and other time-consuming manual procedures.

As a further example of required brake testing, during trips longer than <NUM>,<NUM> miles, a train consist needs to stop so that a Class 1A intermediate brake test can be performed on each of its railcars. The need to interrupt the travel of the train consist to perform this testing can significantly reduce the operating efficiency of the railroad.

Railroad operators need to secure trains, railcars, and locomotives to prevent unattended or other unintended movement, which can create a dangerous situation within a railyard or rail network. For example, unintended movement can occur when the air in the brake line of a train is depleted, which can result in a reduction in the retarding force holding the train.

Unattended railcars typically are secured through the use of manually-actuated hand brakes, such as those described in <CIT>, <CIT>, and <CIT>. Due to the dangers of unattended movement, it is desirable to obtain confirmation, before the operator leaves the train consist unattended, that the railcars have been secured from movement by the application of their respective hand brakes. It is also desirable to obtain confirmation, before the train consist begins moving, that the hand brakes on each railcar have been released. If hand brakes are not released before a railcar begins moving, a damaging event, such as wheel flats, can occur.

An undesired emergency (UDE) brake application occurs when air pressure contained within the air brake system of a train consist is quickly released, causing the railcars within the consist to rapidly apply their brakes. Railroad operators desire to reduce the occurrence of UDE brake applications in order to improve the reliability and efficiency of the railroad network. Reducing UDE brake applications requires identification of when, and why UDE brake applications have occurred, so that repairs and other corrective actions can be undertaken.

Railroads also desire to validate the railcars and locomotives of train consists before leaving the railyard. This can entail obtaining a count of the assets in the train consist, and the order of the locomotives and railcars in the consist.

In view of the above, it is desirable to provide railroad operators with the following capabilities relating to the monitoring and testing of railcar braking systems, and alerting railroad operations centers and locomotive operators, i.e., the train engineers, of actual and potential maintenance issues and other problems with the braking systems.

Document <CIT> discloses an on-board train brake safety monitoring and fault action system that compares actual train brake power with expected train brake power to provide real time reporting to the train driver of the margin between the actual brake power and a safe threshold.

Applicant currently is unaware of any reliable system for remotely monitoring the status of brake systems on trains. Accordingly, it is desirable to provide systems and methods for the real-time or near real-time, on-board monitoring of various operational parameters of train, locomotive, and railcar brake systems, and for analyzing the readings in real time, or near real time to predict or timely detect anomalous operational conditions and to issue appropriate alerts regarding such conditions.

The systems and methods disclosed herein are intended to address deficiencies in prior art monitoring systems for the brake systems for trains, railcars, and locomotives. The systems include hierarchical arrangements of components that provide a distributed data analysis capability for detecting operational anomalies at various levels of the hierarchy, and provide for the flow of data, events notifications, and alerts to a central point.

In one form, the invention provides a system according to claim <NUM> for detecting the operational status of a brake system on a railcar. The system includes a sensor located on the railcar and configured to generate an output indicative of a magnitude of a braking force applied by the braking system. The system further includes a computing device communicatively coupled to the sensor and which includes a computer-readable storage medium comprising one or more programming instructions. When executed, the instructions cause the computing device to: receive from the sensor an indication of the magnitude of a braking force applied by the braking system in response to an instruction to increase or decrease the braking force; compare the response to possible responses of the braking system to the instruction to increase or decrease the braking force; and based on the comparison, generate at least one of a message and an alert indicating the status of the brake system. This can further include one or more additional sensors located on the railcar and configured to generate outputs indicative of any of the following: the magnitude of a pressure in a brake pipe of the railcar, which pressure controls the application of the railcar brake pneumatically, and a sensor for the status of a hand brake on the railcar.

Each railcar may be equipped with one or more wireless sensor nodes, referred to in the singular as a "WSN. " The WSNs on a particular railcar are arranged in a network controlled by a communication management unit ("CMU"), which usually is located on the same railcar. This type of network is referred to herein as a "railcar-based network. " The WSNs collect data regarding various operational parameters of their associated railcar, and are capable of detecting certain anomalies based on the collected data. When anomalous operational data is detected, an alert can be raised and the data can be communicated to the associated CMU located on the railcar. Although mesh networks are used in the embodiments illustrated herein, other types of network topologies can be used in the alternative.

The CMUs located on each railcar also are arranged in a network which is controlled by a powered wireless gateway ("PWG") typically located in the locomotive. This type of network is referred to herein as a "train-based network. " Although mesh networks are used in the embodiments illustrated herein, other types of network topologies can be used in the alternative.

The train-based network communicates over the length of the train consist, and can deliver information about the railcars equipped with a CMU to a powered host or control point. The host or control point can be a locomotive of the train consist; or another asset with access to a power source, and having the ability to communicate with a remote railroad operations center.

The following drawings are illustrative of particular embodiments of the present invention and do not limit the scope of the present invention. The drawings are not to scale and are intended for use in conjunction with the explanations in the following detailed description. Various non-limiting embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views.

The term "railcar," as used herein, means a single railcar; or two or more railcars <NUM> which are permanently connected, often referred to by those of skill in the art as a "tandem pair", "three-pack", "five-pack", etc. The terms "train consist" or "consist," as used herein, mean a connected group of railcars and one or more locomotives. A train consist <NUM> is depicted schematically in <FIG>. The train consist <NUM> is made up of a locomotive <NUM>, and a plurality of the railcars <NUM>. This particular configuration of the train consist <NUM> is depicted for illustrative purposes only. The systems and methods disclosed herein can be applied to train consists having a different number of locomotives <NUM> and railcars <NUM> than the train consist <NUM>.

The figures depict a brake monitoring system <NUM>, and variants thereof. The system <NUM> is described in connection with the railcars <NUM>, a description of which is provided below. Each railcar <NUM> has a braking system <NUM>, a description of which also is provided below. The system <NUM> includes a combination of sensors and signal processing equipment that allow the system <NUM> to sense various operating parameters of the braking system <NUM>; to process and analyze data relating to the operating parameters; to make logical decisions and inferences regarding the condition of the brake system <NUM>, and generate alerts and other status information based thereon; to form networks within each railcar <NUM>, and throughout the train consist <NUM>; and to communicate information regarding the status of brake system <NUM> to sources within, and external to the train consist <NUM>.

As discussed below, the specific configuration of the brake monitoring system <NUM> for a particular application is selected based on the diagnostic, alerting, and reporting requirements imposed on the system <NUM>, which in turn are dependent upon the requirements of the user. Typically, the capabilities of the system <NUM> are tailored to specific user requirements by varying the number, locations, and types of sensors used within the system <NUM>. This concept is discussed below, where alternative embodiments of system <NUM>, having capabilities different than, or in addition to, those of the system <NUM>, are described.

The system <NUM> includes one or more communication management units ("CMUs") <NUM>, depicted in <FIG>. Each CMU <NUM> is located on a respective railcar <NUM>, and when one or more WSNs <NUM> are installed on the railcar <NUM>, the CMU <NUM> manages a railcar-based network <NUM> overlaid on that particular railcar <NUM>.

The system <NUM> also includes wireless sensor nodes (WSNs) <NUM>, also depicted in <FIG>. One or more of the WSNs <NUM> are mounted on each network-enabled railcar <NUM>, and form part of the railcar-based network <NUM> associated with that railcar <NUM>. The WSNs <NUM> communicate with, and are controlled by their associated CMU <NUM>, which typically is the CMU <NUM> installed on the same railcar <NUM> as the WSNs <NUM>. The WSNs <NUM> on the railcar <NUM> and their associated CMU <NUM> form the railcar-based network <NUM> for that particular railcar <NUM>.

The system <NUM> further includes a powered wireless gateway ("PWG") <NUM>. The PWG <NUM> is located on the locomotive <NUM>. Alternatively, the PWG <NUM> can be positioned at other locations on the train consist <NUM>, preferably where a source of external power is available or in a railyard. The PWG <NUM> manages a train-based network <NUM> overlaid on the train consist <NUM>, and communicates directly with each of the CMUs <NUM> on the various railcars <NUM> in the train consist <NUM>. The PWG <NUM>, the CMUs <NUM>, and WSNs <NUM> make up the train-based network <NUM>.

Each CMU <NUM> can comprise a processor; a power source such as a battery, energy harvester, or internal power-generating capability; a global navigation satellite system (GNSS) device such as a global positioning system ("GPS") receiver, Wi-Fi, satellite, and/or cellular capability; a wireless communications capability for maintaining the railcar-based network <NUM>; a wireless communication capability for communicating with the train-based network <NUM>; and optionally, one or more sensors, including, but not limited to, an accelerometer, gyroscope, proximity sensor or temperature sensor. Although GPS is used in the embodiments described herein, any type of GNSS system or devices can be used in alternative embodiments. For example, GLONASS and BeiDou can be used in lieu of GPS; and other types of GNSS are in development.

The CMU <NUM> communicates with the WSNs <NUM> within its associated railcar-based network <NUM> using open standard protocols, such as the IEEE <NUM> <NUM>. <NUM>, Bluetooth LE, or Bluetooth Mesh radio standards. As noted above, the CMU <NUM> also forms part of the train-based network <NUM>, which includes all of the CMUs <NUM> in the train consist <NUM>; and the PWG <NUM>, which controls the CMUs <NUM>.

Each CMU <NUM> performs the following functions: managing the low-power railcar-based network <NUM> overlaid on its associated railcar <NUM>; consolidating data from one or more WSNs <NUM> in the network <NUM> and applying logic to the data to generate messages and warning alerts to a host such as the locomotive <NUM> or a remote railroad operations center; supporting built-in sensors, such as an accelerometer, within the CMU <NUM> to monitor specific attributes of the railcar <NUM> such as location, speed, and accelerations, and to provide an analysis of this information to generate alerts; and supporting bi-directional communications upstream to the host or control point, such as the locomotive <NUM> and/or an off-train, remote railroad operations center; and downstream to its associated WSNs <NUM> on the railcar <NUM>.

The CMUs <NUM> can communicate with the PWG <NUM> on a wireless basis. Alternatively, the CMUs <NUM> can be configured to communicate through a wired connection, such as through the electronically controlled pneumatic (ECP) brake system of the train consist <NUM>.

Each CMU <NUM> is capable of receiving data and/or alarms from its associated WSNs <NUM>; drawing inferences from the data or alarms regarding the performance of the railcar <NUM> and its braking system <NUM>; and transmitting the data and alarm information to the PWG <NUM> or other remote receiver. The CMU <NUM> can be a single unit. In addition to communicating with, controlling, and monitoring the WSNs <NUM> in the local railcar-based network <NUM>, the CMU <NUM> has the capability of processing the data it receives from the WSN's <NUM>. The CMU <NUM> also serves as a communications link to other locations, such as the PWG <NUM>. The CMUs <NUM> optionally can be configured with off-train communication capabilities similar to those of the PWG <NUM>, to allow the CMUs <NUM> to communicate with devices off of the train consist <NUM>, such as a server located at a remote railroad operations center.

The PWG <NUM> controls the train-based network <NUM> overlaid on the train consist <NUM>. The PWG <NUM> can include a processor; a GPS or other type of GNSS device; one or more sensors, including but not limited to an accelerometer, a gyroscope, a proximity sensor, and a temperature sensor; a satellite and or cellular communication system; a local wireless transceiver, e.g. WiFi; an Ethernet port; a high capacity network manager; and other means of communication. The PWG <NUM> can receive electrical power from a powered asset in the train consist <NUM>, such as the locomotive <NUM>. Alternatively, or in addition, the PWG <NUM> can receive power from another source, such as a solar-power generator or a high-capacity battery. Alos, the PWG <NUM> can be configured to perform the logical operations.

The components and configuration of the PWG <NUM> are similar to those of the CMUs <NUM>, with the exception that the PWG <NUM> typically draws power from an external source, while the CMUs <NUM> typically are powered internally. Also, the PWG <NUM> collects data and draws inferences regarding the overall performance of the train consist <NUM> and the train-based network <NUM>. The CMUs <NUM>, by contrast, collect data and draw inferences regarding the performance of individual railcars <NUM> and their associated railcar-based network <NUM>.

Also, the PWG <NUM> is a computing device that includes a processor; and a computer-readable storage medium comprising one or more programming instructions that, when executed by the processor, cause the PWG <NUM> to perform the various logical functions associated with the brake monitoring system <NUM> and described below. Alternatively, these logical functions can be performed by another computing device, such as a specially modified CMU <NUM> or WSN <NUM>; or by a central server located at a remote location such as a railroad operations center.

Each WSN <NUM> collects data via its associated sensors. The sensors can be located internally within the WSN <NUM>. Alternatively, the sensors can be located external to the WSN <NUM>, and can communicate with the WSN <NUM> by cabling or other suitable means, including wireless means. The WSN <NUM> can process and analyze the data to determine whether the data needs to be transmitted immediately; held for later transmission; and/or aggregated into an event or alert. The WSNs <NUM> and their associated sensors can be used to sense a monitored parameter, e.g., gate open or close events, brake force, etc.; or to determine the status of a parameter, e.g., the position of a gate lever. Examples of WSNs <NUM> are disclosed in <CIT>.

The WSNs <NUM> can be equipped, or otherwise associated with virtually any type of sensor, depending on the particular parameter or parameters that the WSN <NUM> will be used to monitor or determine. For example, the WSNs <NUM> can be equipped or associated with one or more of: a proximity sensor; a temperature sensor; a pressure sensor; a load cell; a strain gauge; a hall effect sensor; a vibration sensor; an accelerometer; a gyroscope; a displacement sensor; an inductive sensor; a piezo resistive microphone; and an ultrasonic sensor. In addition, the sensor can be a type of switch, including, for example, reed switches and limit switches. A hand-brake monitor sensor is described in <CIT> and <CIT>; this sensor is an example of a type of remote sensor that uses a strain gauge and can be incorporated into a WSN <NUM>.

The specific configuration of each WSN <NUM> varies with respect to the number, and types of sensors with which the WSN <NUM> is equipped or otherwise associated. The sensing capabilities of the WSN's <NUM> installed on a particular railcar <NUM> are dependent upon the specific configuration of the brake monitoring system <NUM>, which in turn is dependent, in part, on the diagnostic, alerting, and reporting requirements imposed on the system <NUM> by the user in a particular application.

Each WSN <NUM> includes the electrical circuitry necessary for the operation of the WSN <NUM>. The electrical circuitry includes the components and wiring needed to operate the particular sensors associated with the WSN <NUM>, and/or to receive and process the output signals generated by the sensors. This circuitry can include, but is not limited to: analog and digital circuitry; CPUs; processors; circuit boards; memory; firmware; and controllers.

The circuitry of the WSN <NUM> can include a main board that accommodates communications circuitry; antennae; a microprocessor; and a daughter board that includes circuitry to read the data from sensors. The main board, daughter board, and/or the sensors also can include a processor that executes firmware to provide intelligence sufficient to perform low-level analysis of the data; and can accept parameters from outside sources regarding when alarms should be raised.

Each WSN <NUM> also includes circuitry for short-range wireless communications; and a long-term power source such as a battery, an energy harvester, or internal power-generating capability. In the exemplary embodiments of the WSNs <NUM> disclosed herein, the power source is a military grade lithium-thionyl chloride battery. The circuitry also provides power conditioning and management functions, including features that conserve battery life by, for example, maintaining the WSN <NUM> in a standby state and periodically waking the WSN <NUM> to deliver readings from its sensors. The WSNs <NUM> optionally can be configured with off-train communication capabilities similar to those of the PWG <NUM>, to allow the WSNs <NUM> to communicate with devices off of the train consist <NUM>, such as a server located at a remote railroad operations center.

The railcar <NUM> is, as a non-limiting example, a box car. The railcar <NUM> can be configured as follows. This description of the railcar <NUM> is provided solely as an illustrative example of a railcar with which the brake monitoring system <NUM> can be used. The brake monitoring system <NUM> can be used in railcars having other configurations, including railcars in the form of hopper cars; flatcars; gondolas; coal cars; tank cars; etc..

As illustrated in <FIG>, the railcar <NUM> comprises an underframe <NUM>; a box <NUM> mounted on the underframe <NUM>; and a first and a second truck 313a, 313b each coupled the underframe <NUM>. The first truck 313a is located proximate a first end of the railcar <NUM>; and the second truck 313b is located proximate a second end of the railcar <NUM>. Each truck 313a, 313b can rotate in relation to the underframe <NUM> about a vertically-oriented central axis of the truck 313a, 313b, to facilitate transit of the railcar <NUM> over curved sections of track.

Referring to <FIG>, each truck 313a, 313b includes two side frames <NUM>; a bolster <NUM> located between and connected to the side frames <NUM>; a center plate <NUM> mounted on the bolster <NUM>; and a center pin <NUM> secured to the bolster <NUM> and extending through the center plate <NUM>. Each truck 313a, 313b is coupled to the underframe <NUM> of the railcar <NUM> by way of the center pin <NUM>, and rotates in relation to the underframe <NUM> about the center pin <NUM>. The underframe <NUM> and the box <NUM> are supported on the trucks 313a, 313b by way of the center plates <NUM>, each of which engages, and rotates in relation to a center sill on the underframe <NUM>.

Each of the trucks 313a, 313b also includes two wheel assemblies <NUM>. The wheel assemblies <NUM> each include an axle <NUM>, and two of the wheels <NUM> mounted on opposite ends of the axle <NUM>. The axles <NUM> are coupled to, and rotate in relation to the side frames <NUM> by way of journal bearings (not shown).

The brake system <NUM> can be configured as follows. This description of the brake system <NUM> is provided solely as an illustrative example of a brake system into which the brake monitoring system <NUM> can be incorporated. The brake monitoring system <NUM> can be incorporated into brake systems having other configurations. For example, the brake system <NUM> uses foundation brake rigging. As shown in <FIG>, the brake monitoring system <NUM>, and variants thereof, can be incorporated into a brake system 100a that uses truck mounted brake rigging.

Referring to <FIG>, <FIG>, and <FIG>, the brake system <NUM> includes a pneumatic brake cylinder <NUM>, a slack adjuster <NUM>, the rigging <NUM>, and eight brake shoes <NUM>. Each brake shoe <NUM> is connected to the rigging <NUM>; and each brake shoe <NUM> is positioned proximate to a respective one of the wheels <NUM>. The rigging <NUM> articulates in a manner that urges each brake shoe <NUM> into and out of contact with an outer tread of its associated wheel <NUM>. Contact between the brake shoe <NUM> and the wheel <NUM> results in friction that produces a braking force on the wheel <NUM>. The force that operates the rigging <NUM> is supplied by an air brake system that includes the brake cylinder <NUM>. As discussed below, the air brake system is an automated system that facilitates simultaneous braking of all the railcars <NUM> of the train consist <NUM> from a single location, to slow and stop the entire train consist <NUM>.

The rigging <NUM> incudes a first rigging subassembly <NUM>, visible in detail in <FIG>. The subassembly <NUM> is associated with the first truck 313a, and includes a first brake beam <NUM> and a second brake beam <NUM>. Two of the brake shoes <NUM> are mounted near the respective ends of the first brake beam <NUM>; another two of the brake shoes <NUM> are mounted near the respective ends of the second brake beam <NUM>.

Each end of the first brake beam <NUM> is positioned in, and supported by a bracket (not shown) mounted on the respective one of the side frames <NUM>, proximate a forward end of the side frame <NUM>. Each end of the second brake beam <NUM> likewise is positioned in, and supported by a bracket mounted on the respective one of the side frames <NUM>, proximate a rearward end of the side frame <NUM>. The forward and rearward directions are denoted in the figures as the "+x" and "-x" directions, respectively. The brackets are configured to restrain the first and second brake beams <NUM>, <NUM> in the vertical and lateral directions, while allowing a limited degree of sliding movement in relation to the side frames <NUM> in the forward and rearward directions.

Referring to <FIG>, the first rigging subassembly <NUM> also includes a first truck lever <NUM>; a second truck lever <NUM>; a truck lever connection <NUM>; and a top rod <NUM>. A lower end of the first truck lever <NUM> is pivotally coupled to the first brake beam <NUM>; an upper end of the first truck lever <NUM> is pivotally coupled to a forward end of the top rod <NUM>. A forward end of the truck lever connection <NUM> is pivotally coupled to the first truck lever <NUM>, at the approximate mid-point of the first truck lever <NUM>.

A lower end of the second truck lever <NUM> is pivotally coupled to the second brake beam <NUM>; and an upper end of the second truck lever <NUM> is pivotally coupled to a forward end of a first load measuring device <NUM>, as shown in <FIG>. A rearward end of truck lever connection <NUM> is pivotally coupled to the second truck lever <NUM>, at the approximate mid-point of the second truck lever <NUM>.

A rearward end of the first load measuring device <NUM> is pivotally coupled to a bracket <NUM>, as shown in <FIG>. The first load measuring device <NUM> is described below. The bracket <NUM> is secured to the underframe <NUM> of the railcar <NUM>. The bracket <NUM> thus acts as an anchoring point for the rigging <NUM>, i.e., the bracket <NUM> connects the articulating rigging <NUM> to the non-articulating underframe <NUM>. Because the load measuring device <NUM> is connected directly to the bracket <NUM>, a portion of the reactive force exerted by the underframe <NUM> in response to the braking force exerted on the wheels <NUM> of the first truck 313a by the rigging <NUM> and the brake shoes <NUM> is transmitted through the load measuring device <NUM>. Thus, the load measuring device <NUM> is subject to a mechanical load that is indicative of, and proportional to the braking force applied to the wheels <NUM> of the first truck 313a.

Referring to <FIG>, <FIG>, and <FIG>, the first rigging subassembly <NUM> also includes a brake lever <NUM>. A first end of the brake lever <NUM> is pivotally coupled to a rearward end of the top rod <NUM>. A second end of the brake lever <NUM> is pivotally coupled to a push rod <NUM> of the brake cylinder <NUM>. The brake cylinder <NUM> is securely mounted on the underframe <NUM>, and thereby acts as another anchoring point for the rigging <NUM>. A forward end of the slack adjuster <NUM> is pivotally coupled to the brake lever <NUM>, proximate a mid-point of the brake lever <NUM>.

The rigging <NUM> also includes a center rod <NUM>, a fulcrumed lever <NUM>, and a second top rod <NUM>. A forward end of the center rod <NUM> is pivotally coupled to a rearward end of the slack adjuster <NUM>. A rearward end of the center rod <NUM> is pivotally coupled to the fulcrumed lever <NUM>, at the approximate mid-point of the fulcrumed lever <NUM>. A first end of the fulcrumed lever <NUM> is pivotally coupled to the underframe <NUM>, and thus serves as an additional anchoring point for the rigging <NUM>. A second end of the fulcrumed lever <NUM> is pivotally coupled to a forward end of the second top rod <NUM>. The rearward end of the second top rod <NUM> is pivotally coupled to a first truck lever <NUM> of a second rigging subassembly <NUM>.

The second rigging subassembly <NUM> is depicted in <FIG> and <FIG>. The second rigging subassembly <NUM> is substantially identical to the first rigging subassembly <NUM>, and identical reference characters are used in the figures to refer to identical components of the first and second rigging subassemblies <NUM>, <NUM>. The second rigging subassembly <NUM>, and the four brake shoes <NUM> associated therewith, apply braking force to the wheels <NUM> of the second truck 313b of the railcar <NUM>. The second load measuring device <NUM> is associated with the second rigging subassembly <NUM>, and is mounted between a second truck lever <NUM> of the second rigging subassembly <NUM>; and another bracket <NUM> secured to a second location on the underframe <NUM>. Thus, the second load measuring device <NUM> is subject to a mechanical load that is indicative of, and proportional to the braking force applied to the wheels <NUM> of the second truck 313b. The second load measuring device <NUM> is substantially identical to the first load measuring device <NUM>.

Referring to <FIG>, the brake system <NUM> further includes a brake valve <NUM>, and a dual-compartment air reservoir <NUM>. The air reservoir <NUM> includes a service reservoir <NUM> and an emergency reservoir <NUM>. The brake cylinder <NUM> is pneumatically actuated, and receives pressurized air from the brake valve <NUM>. The brake valve <NUM> directs pressurized air from the air reservoir <NUM> to the brake cylinder <NUM>. The pressured air, upon entering the brake cylinder <NUM>, acts against a piston (not shown) within the brake cylinder <NUM>, causing the piston to move forward against the bias of an internal spring (also not shown). The piston is connected to the push rod <NUM> of the brake cylinder <NUM>, so that movement of the piston imparts a corresponding movement to the push rod <NUM>.

The rigging <NUM> is actuated by the brake cylinder <NUM>. In particular, the forward movement of the push rod <NUM> in response to the pressurization of the brake cylinder <NUM> causes the brake lever <NUM>, which is pivotally coupled to the push rod <NUM>, to rotate about the point at which the brake lever <NUM> is coupled to the slack adjuster <NUM>. The rotation is in a clockwise direction, from the perspective of <FIG>. The rotation of the brake lever <NUM> pulls the attached top rod <NUM> rearward, which in turn causes the top of the first truck lever <NUM> to move rearward.

The rearward movement of the first truck lever <NUM> causes the first truck lever <NUM> to rotate in a counterclockwise direction from the perspective of <FIG>, about the point at which the truck lever connection <NUM> is coupled to the first truck lever <NUM>. The rearward movement of the first truck lever <NUM> also causes the truck lever connection <NUM> to move rearward, which in turn causes the second truck lever <NUM> to rotate in a clockwise direction, about the point at which the second truck lever <NUM> is coupled to the clevis <NUM>. The rotation of the first and second truck levers <NUM>, <NUM> causes the first and second beams <NUM>, <NUM> to move forward and rearward, respectively, in relation to the side frames <NUM>. The movement of the first and second beams <NUM>, <NUM> urges the brake shoes <NUM> on each of the first and second beams <NUM>, <NUM> into contact with their associated wheels <NUM>, resulting in the application of a braking force to the wheels <NUM> of the first truck 313a.

The rotation of the brake lever <NUM> in response to movement of the push rod <NUM> also causes the slack adjuster <NUM> to move rearward, which imparts a corresponding rearward movement to the center rod <NUM>. The rearward movement of the center rod <NUM>, in turn, causes the fulcrumed lever <NUM> to rotate in a clockwise direction from the perspective of <FIG>, about the point at which the fulcrumed lever <NUM> is coupled to the underframe <NUM>. The rotation of the fulcrumed lever <NUM> imparts a rearward movement to the second top rod <NUM>, which in turn actuates the second rigging subassembly <NUM> in a manner substantially identical to the above-described actuation of the first rigging subassembly <NUM>. The actuation of the second rigging subassembly <NUM> results in the application of a braking force to the wheels <NUM> of the second truck 313b.

The braking force applied by the first and second rigging subassemblies <NUM>, <NUM> is removed by releasing the air pressure within the brake cylinder <NUM>, which in turn causes the push rod <NUM> to move rearward under the bias of the internal spring of the brake cylinder <NUM>. The rearward movement of the push rod <NUM> causes the various components of the first and second rigging subassemblies <NUM>, <NUM> to articulate in a manner opposite to that described above in relation to the application of braking force, resulting in movement of the brake shoes <NUM> away from their associated wheels <NUM>.

The brake system <NUM> also includes a manually operated hand brake <NUM>, depicted in <FIG>. The hand brake <NUM> includes a handle assembly mounted on the forward or rearward end of the box <NUM>. The handle assembly includes a hand wheel <NUM>, an axle (not shown), and gearing (also not shown) that mechanically couples the hand wheel <NUM> and the axle. The gearing provides a mechanical advantage that facilitates manual rotation of the hand wheel <NUM> by a single operator.

The hand brake <NUM> also includes a first chain <NUM> having a first end connected to the axle; a bell crank <NUM> connected to a second end of the first chain <NUM>; and a second chain <NUM> having a first end connected to the bell crank <NUM>, and a second end connected to the second end of the brake lever <NUM>.

Rotation of the hand wheel <NUM> in a first direction imparts rotation to the axle, which in turn causes a portion of the first chain <NUM> to be wound around the axle, and the second end of the first chain <NUM> to move generally upward, from the perspective of <FIG>. The upward movement of the first chain <NUM> rotates the bell crank <NUM>. The rotation of the bell crank <NUM> causes the second chain <NUM> to move generally to the right, from the perspective of <FIG>, which in turn causes the brake lever <NUM> to rotate in a clockwise direction. The clockwise rotation of the brake lever <NUM> results in actuation of the rigging <NUM> in the above-described manner, which in turn results in the application of braking force to the wheels <NUM>. Subsequent rotation of the hand wheel <NUM> in a direction opposite the first direction causes the various components of the rigging <NUM> to return to their original positions in response to the bias of the internal spring of the brake cylinder <NUM>, thereby removing the braking force from the wheels <NUM>.

The brake valve <NUM> directs pressurized air to the brake cylinder <NUM> to actuate the rigging <NUM>. The brake valve <NUM> facilitates charging, i.e., pressurization, of the air reservoir <NUM>; the release of air pressure from the air reservoir <NUM>; and maintenance of the air pressure within the air reservoir <NUM>. Pressurized air is produced by a compressor (not shown) located in the locomotive <NUM>. The pressurized air is directed from the compressor to the brake valve <NUM> by a train air line, or brake pipe <NUM>. The brake pipe <NUM> also services the other railcars <NUM> in the train <NUM>, and thus extends over substantially the entire length of the train consist <NUM>. The portion of the brake pipe <NUM> associated with each railcar <NUM> connects to the brake-pipe portions of the railcars <NUM> in front of, and to the rear of that particular railcar <NUM>.

The brake valve <NUM> has a service portion <NUM> and an emergency portion <NUM>. The engineer can apply normal braking force by moving a brake handle in the locomotive <NUM> to a "service" position. This results in a gradual, controlled reduction in the air pressure within the brake pipe <NUM>. For example, air pressure may be gradually reduced from about <NUM> psi to about <NUM> psi during the application of normal braking force. The service portion <NUM> of the brake valve <NUM>, in response to this reduction in pressure, closes a valve <NUM> located in the airflow path between the brake valve <NUM> and the brake cylinder <NUM>, and directs air from the service reservoir <NUM> into the brake cylinder <NUM>. This causes the pressure within the brake cylinder <NUM> to increase, which in turn causes the piston and the attached push rod <NUM> to move forward. The forward movement of the push rod <NUM>, as discussed above, causes the rigging <NUM> to articulate in a manner that results in the application of braking force to the wheels <NUM>.

The air pressure in the service reservoir <NUM> decreases until the air pressure in the service reservoir <NUM> approximately equals that in the brake pipe <NUM>. At this point, the service portion <NUM> of the brake valve <NUM> once again isolates the brake cylinder <NUM> from the brake pipe <NUM>. Barring any significant leaks in the brake cylinder <NUM>, the pressure within the brake cylinder <NUM> thereafter remains at a substantially constant level; and the brake shoes <NUM> remain in contact with their associated wheels <NUM>, resulting in the continued application of braking force to the wheels <NUM>.

The brake system <NUM> can include an empty/load valve <NUM> that identifies whether the railcar <NUM> is empty or loaded, based on the compression of the springs on the trucks 313a, 313b of the railcar <NUM>. The amount of air supplied to the brake cylinder <NUM> during braking operations is modified based on an empty or loaded condition. Because a loaded railcar <NUM> requires more braking pressure than an empty railcar <NUM>, the brake pressure is reduced to a minimum value by the empty/load valve if the railcar <NUM> is empty; and is increased to a maximum value when the railcar <NUM> is at or near its maximum operating weight.

The engine operator releases the braking force by moving the brake handle to a "release" position. This results in an increase in the pressure within the brake pipe <NUM>, which in turn causes the service portion <NUM> of the brake valve <NUM> to open the valve <NUM>. Opening the valve <NUM> causes the pressurized air within the brake cylinder <NUM> to be discharged to the atmosphere, which causes the piston and the attached push rod <NUM> to move rearward under the bias of the internal spring of the brake cylinder <NUM>. As discussed above, the rearward movement of the push rod <NUM> causes the rigging <NUM> to articulate in a manner that moves the brake shoes <NUM> away from their associated wheels <NUM>, thereby removing the braking force on the wheels <NUM>.

Also, the positive pressure differential between the brake pipe <NUM> and the service reservoir <NUM> causes the service portion <NUM> of the brake valve <NUM> to direct pressurized air from the brake pipe <NUM> to the service reservoir <NUM>, causing the air pressure in the service reservoir <NUM> to increase. When the pressures in the brake pipe <NUM> and the service reservoir <NUM> equalize, the brake valve <NUM> interrupts the flow of pressurized air between the brake pipe <NUM> and the auxiliary reservoir <NUM>, isolating the service reservoir <NUM> and sealing the pressurized air within the service reservoir <NUM>. The service reservoir <NUM> at this point is ready to provide air the brake cylinder <NUM> when braking force is subsequently requested by the engine operator.

The emergency portion <NUM> of the brake valve <NUM> operates in a manner similar to the service portion <NUM>, with the exception that the emergency portion <NUM> causes a faster and more forceful application of braking force. Emergency braking can be initiated manually by the train operator, by pulling an emergency braking handle, which causes an immediate discharge of the air pressure with the brake pipe <NUM>; or automatically in the event of a significant leak in brake pipe <NUM> or other event that results in a rapid loss of air pressure within the brake pipe <NUM>. The emergency portion <NUM> is configured to respond to a rapid drop in air pressure within the brake pipe <NUM> by closing the valve <NUM> and simultaneously directing air from both the emergency reservoir <NUM> and the service reservoir <NUM> to the brake cylinder <NUM>, resulting in a rapid application of full braking force.

As noted above, the capabilities of the system <NUM> can be tailored to the requirements of a particular application through the number, locations, and types of sensors incorporated into the system. The following types of sensors can be incorporated into the system <NUM>, and alternative embodiments thereof. These sensors are described for illustrative purposes only; other types of sensors, configured to measure the same, or different parameters than those noted below, can be used in alternative embodiments of the system <NUM>.

<FIG> and <FIG> depict a hand brake sensor <NUM> that can be incorporated into the system <NUM> and variants thereof. The sensor <NUM> can be used to monitor the tension applied by the hand brake <NUM>. The sensor <NUM> is communicatively coupled to a WSN <NUM>. The WSN <NUM> is configured to interface with the sensor <NUM>, and in addition, contains the general functionality of WSNs <NUM> described above.

The hand brake sensor <NUM> can be incorporated into the second chain <NUM> of the hand brake <NUM>. The sensor <NUM> uses a strain gauge to determine the force being applied to the hand brake <NUM>. The hand brake sensor <NUM> can be configured as disclosed in <CIT>, the entire contents of which are incorporated by reference herein. The readings from the hand brake sensor <NUM> are sent by the WSN <NUM> to the associated CMU <NUM>, which forwards the readings to the PWG <NUM> or other computing device for further analysis, reporting, and alerting. The sampling rate of the sensor <NUM> can be set, and changed by the CMU <NUM> based on the operational state of the railcar <NUM>.

The first and second load measuring devices <NUM> are identical; and unless otherwise noted, references to a single load-measuring device <NUM> apply equally to both of the first and second load measuring devices <NUM>. As discussed above and as shown in <FIG>, <FIG>, and <FIG>, each load-measuring device <NUM> is mounted between, and mechanically connects the articulating rigging <NUM> of the brake system <NUM> with the non-articulating underframe <NUM> of the railcar <NUM>. This arrangement subjects the load measuring devices <NUM> to a mechanical load whenever the brake system <NUM> applies braking force to the wheels <NUM> of the railcar <NUM>, whether through the brake cylinder <NUM> or the hand brake <NUM>. The load measuring device <NUM> generates an electrical signal representative of the mechanical load on the load measuring device <NUM>, thereby providing an indication of whether the brake system <NUM> is generating a braking force on the railcar <NUM>, and allowing the magnitude of the braking force to be determined. The first and second load measuring devices <NUM> can be mounted at locations other than those described above, in alternative embodiments of the system <NUM>. In particular, the first and second load measuring devices <NUM> can be mounted anywhere within the brake rigging <NUM> downstream of the brake lever <NUM>. As an example, the devices <NUM> can be inserted between rods of the rigging such that the load passes through it.

Force sensors in the form of the above-described hand bake sensor <NUM> can be used as the load measuring devices <NUM>. Other types of force sensors can be used as the load measuring devices <NUM> in alternative embodiments. Each load measuring device <NUM> is communicatively coupled to an associated WSN <NUM>. The WSN <NUM> determines the mechanical load on its associated load measuring device <NUM> based on the output of the load measuring device <NUM>. The WSN <NUM> sends this information to an associated CMU <NUM> mounted on the same railcar <NUM> as the WSN <NUM>, or to another computing device. Alternatively, or in addition, the WSN <NUM> can send the information to a PWG <NUM> located on the locomotive <NUM> or in a railyard; or to a remote server. For example, the CMU <NUM>, upon receiving the noted information from the WSN <NUM>, can relay the information to the PWG <NUM> located on the locomotive <NUM>. The information can be processed and analyzed to assess the condition of the brake system <NUM>.

When the brakes are activated by the brake cylinder <NUM> or the handbrake <NUM>, the resulting load is transferred through the brake rigging <NUM>, and will exert a balanced load on the brake shoes <NUM> and the dead lever anchor <NUM>. This load is always transferred through the load measuring devices <NUM> due to their respective locations within the rigging <NUM>, and can be measured by the WSNs <NUM> associated with the load measuring devices <NUM>.

The respective WSNs <NUM> associated with each load measuring device <NUM> provide the excitation voltage to the load sensor <NUM>; register the response of the load sensor <NUM> to the mechanical loading of the dead lever <NUM>; convert the response into a force reading; and transmit the force reading to the associated CMU <NUM> other computing device, which forwards the readings to the PWG <NUM> or other computing device for further analysis, reporting, and alerting.

<FIG> and <FIG> depict a pressure sensor <NUM> that can be incorporated into the system <NUM> and variants thereof. The sensor <NUM> can be mounted on air pipe <NUM>, and includes an analog pressure sensor, and a digital pressure switch. The analog pressure sensor and the pressure switch can be attached to the brake pipe <NUM> as shown in <FIG>, so that the analog pressure sensor and the pressure switch can sense air pressure within the brake pipe <NUM>. The analog pressure sensor and the pressure switch are communicatively coupled to a WSN <NUM>. The WSN <NUM> is configured to interface with these components, and in addition, contains the general functionality of WSNs <NUM> described above.

The pressure switch has a predetermined threshold that will trigger a reading, i.e., an electrical output, in response to an increase or decrease in air pressure above, or below a predetermined threshold. When the trigger is activated, the analog pressure sensor immediately is activated to sample at a fast rate. This information is combined by the WSN <NUM> into a message that contains the exact time of the trigger; and several pressure readings obtained immediately after the trigger activation at a predetermined and known sampling rate. The message is sent by the WSN <NUM> to the associated CMU <NUM> or other computing device, which forwards the message to the PWG <NUM> or another computing device for further analysis, reporting, and alerting.

In addition, the analog pressure sensor also samples the brake pipe pressure at a continual, but low sample rate. The sampling rate can be set, and changed by the CMU <NUM> based on the operational state of the railcar <NUM>, e.g. whether the train consist <NUM> is operating, or parked.

<FIG> depict a slack adjuster sensor <NUM> that can be incorporated into the system <NUM> and variants thereof. The slack adjuster sensor <NUM> can be used to measure the overall length of the slack adjuster <NUM>, and any changes to that length. The sensor <NUM> is integrated into a WSN <NUM>. The WSN <NUM> is configured to interface with the sensor <NUM>, and in addition, contains the general functionality of WSNs <NUM> described above.

The sensor <NUM> incorporates a distance-measuring, or displacement sensor, such as a Hall Effect or optical sensor, to determine the distance by which the rod of the slack adjuster <NUM> is extended from its housing; this distance, in turn, is used to calculate the overall length of the slack adjuster <NUM>. The slack adjuster sensor <NUM> is an analog sensor that, in conjunction with the WSN <NUM>, calculates and reports a specific distance. The sensor <NUM> samples at a continual, but slow sampling rate. The resulting readings are sent by the WSN <NUM> to the associated CMU <NUM>, which forwards the readings to the PWG <NUM> for further analysis, reporting, and alerting. The sampling rate can be set, and changed by the CMU <NUM> based on the operational state of the railcar <NUM>.

<FIG> depict a wheel temperature sensor <NUM> that can be incorporated into the system <NUM> and variants thereof. The sensor <NUM> can be used to monitor the tread temperature of a wheel <NUM> of the railcars <NUM>. The sensor <NUM> is integrated into a WSN <NUM>. The WSN <NUM> is configured to interface with the sensor <NUM>, and in addition, contains the general functionality of WSNs <NUM> described above.

The wheel temperature sensor <NUM> is mounted in an area onboard the railcar <NUM>, such as the side frame <NUM>, from where the sensor <NUM> has an unobstructed line-of-sight to the tread of the wheel <NUM>. The sensor <NUM> uses a non-contact temperature measurement techniques, such as optical temperature measurement, to determine the temperature of the wheel tread. The sensor <NUM> is an analog sensor that, in conjunction with the WSN <NUM>, determines and reports a specific temperature. The sensor <NUM> samples at a continual, but slow sampling rate. The resulting readings are sent by the WSN <NUM> to the associated CMU <NUM> or other computing device, which forwards the readings to the PWG <NUM> or other computing device for further analysis, reporting, and alerting. The sampling rate can be set, and changed by the CMU <NUM> based on the operational state of the railcar <NUM>.

The system <NUM> can be configured to determine whether the train consist <NUM> has effective brakes, without a need for a manual inspection of the brakes. The system <NUM> also can be configured to act as a monitoring system that can provide a locomotive operator with a "check brake" indicator for any railcars <NUM> with non-functioning, or malfunctioning brakes. The system <NUM> also can be configured to provide the operator with the ability to electronically test, from the locomotive <NUM>, for "cold wheel cars," i.e., railcars <NUM> in which the braking system did not activate during a braking event for the train consist <NUM>. It is believed that the checks provided by some embodiments of the system <NUM> can result in a waiver for the Class 1A intermediate air brake test, which would allow the limit for non-stop travel of the train consist <NUM> to be extended to <NUM>,<NUM> miles, from the current limit of <NUM>,<NUM> miles. Additional diagnostic, reporting, and alerting capabilities of the system <NUM> are described below.

Four variants of the brake-monitoring system <NUM> are described immediately hereafter. The variants incorporate different types and/or numbers of sensors, to give these variants different levels of diagnostic, reporting, and alerting capabilities.

<FIG> schematically depicts a variant of the system <NUM> in the form of a "minimum" electronic brake monitoring system 10a, used in conjunction with the brake system <NUM>. The system 10a includes a single brake force sensor, referred to in <FIG> as a "Dead Lever Sensor. " A load measuring device <NUM> as described above can be used as the brake force sensor; other types of load-measuring devices, including but not limited to other types of strain gauge and displacement sensors, can be used in the alternative. The load measuring device <NUM> can be mounted at an anchoring point between the rigging <NUM> of the brake system <NUM> and the underframe <NUM> of the railcar <NUM>, in the manner discussed above in relation to the first load measuring device <NUM>. The load measuring device <NUM> operates in a manner substantially identical to the first load measuring device <NUM> discussed above. As also discussed above, the WSN <NUM> of the load sensor <NUM> communicates wirelessly with a CMU <NUM> or other computing device located on the same, or another, railcar <NUM>; or communicates wirelessly directly with a PWG <NUM> located elsewhere on, or off the train consist <NUM>; or with a central server located at a remote location such as a railroad operations center. The CMU <NUM>, in turn, communicates wirelessly with the PWG <NUM> located in the locomotive <NUM> or, in alternative embodiments, with a PWG <NUM> located elsewhere on, or off the train consist <NUM>; or with a central server located at a remote location such as a railroad operations center.

<FIG> schematically depicts another variant of the system <NUM> in the form of a "basic" electronic brake monitoring system 10b. The system 10b is substantially identical to the system 10a, with the exception that the system 10b includes two of the brake force sensors. Load measuring devices <NUM> as described above can be used as the brake force sensors; other types of load-measuring devices can be used in the alternative. The load measuring devices <NUM> can be mounted at anchoring point between the rigging <NUM> of the brake system <NUM> and the underframe <NUM> of the railcar <NUM>, in the manner discussed above in relation to the first and second load measuring devices <NUM>. Accordingly, the electronic brake monitoring system 10b operates in a similar manner to the system 10a, but provides additional data regarding the braking operation of the railcar <NUM> due to the presence of an additional brake force sensor.

During operation of the electronic brake monitoring systems 10a, 10b, the load measuring device(s) <NUM> are configured to sample their respective load readings at regular intervals, e.g., every <NUM> seconds; and to monitor for rising or falling values in the braking force. Threshold values for the braking force are predetermined, based on known braking characteristics of the railcar(s) <NUM> during various operational states of the train consist <NUM>, e.g., stopped, moving, etc. The load measuring sensors <NUM> are further configured to determine when the force readings cross above or below the threshold value corresponding to the current operational state. Whenever a threshold value is crossed, the WSN <NUM> of the load sensing device <NUM> sends a notification of the threshold crossing to its corresponding the CMU <NUM>. The CMU <NUM>, in turn, sends that information, along with an identification of the particular railcar <NUM> associated with the reading, to the PWG <NUM> on the locomotive <NUM>. The PWG <NUM> monitors and compares the threshold-crossing information from all of the train-based network-enabled railcars <NUM> in the train consist <NUM>; and the PWG <NUM> generates an alert or other indication for the locomotive operator and/or remote operations center upon identifying outlier readings in the threshold crossing information for a particular railcar <NUM>.

Additionally, even in the event that threshold crossings are not detected, a brake-force measurement from each load measuring device <NUM> can be sent to the associated CMU <NUM> and the PWG <NUM> at predetermined intervals, e.g., every <NUM> minutes. Also, routine status and network health messages regarding the load measurement devices <NUM>, other WSNs <NUM> and sensors on the railcar <NUM>, and the CMU <NUM> can be sent to the PWG <NUM> at predetermined intervals.

As the load measurement devices <NUM> and the CMU <NUM> send periodic messages to the PWG <NUM>, the PWG <NUM> processes the messages in order to generate alerts regarding the brake forces associated with each railcar <NUM>. The locomotive <NUM> can include a display <NUM>, such as a monitor, tablet, LCD display, etc., depicted schematically in <FIG> and <FIG>. The display <NUM> communicates with the PWG <NUM>, and is configured to display a real-time, or near real-time alert of specific railcars <NUM> with malfunctioning or non-functioning brakes, thereby allowing the operator, rail inspectors, and others to readily determine the specific railcars <NUM> that should be inspected for potential braking issues or other irregularities. Additionally, as discussed below, the electronic brake monitoring systems 10a, 10b allow the operator to perform electronic brake tests when the train consist <NUM> is at rest, with the brakes of all the railcars <NUM> set; and the test results for each railcar <NUM> can be clearly and visibly displayed and confirmed on the display <NUM>.

The systems 10a, 10b can be configured to perform the following logic operations. These particular operations are described for illustrative purposes only; the systems 10a, 10b can be configured to perform other logic operations in addition to, or in lieu of the following operations. Also, the various operating modes discussed below can be selected by the operator via the display <NUM> or other suitable means.

The brake-monitoring systems 10a, 10b can be configured to operate in a "Train Operating" mode. When operating in this mode, the display <NUM> within the locomotive <NUM> provides real-time, or near real-time alerts, while the train consist <NUM> is operating, regarding specific railcars <NUM> having non-functional or malfunctioning brakes. The alerts can be enabled or disabled by the train operator during the duration of the trip.

In this operating mode, prior to movement of the train consist <NUM>, the PWG <NUM> identifies a total count of train-based network-enabled railcars <NUM>, and those railcars <NUM> having fully-operational CMUs <NUM> and/or WSNs <NUM>. The systems 10a, 10b can provide the operator, by way of the display <NUM>, with a list manifest of railcars <NUM> in the train consist <NUM>, a list of railcars <NUM> requiring maintenance, etc. The PWG <NUM> then confirms whether the brake-force readings from all of the load measuring devices <NUM> are in the same threshold state, i.e., above or below a predetermined "Threshold <NUM>" value. In this non-mobile state, any railcars <NUM> having outlier sensor readings are flagged for inspection or maintenance. Force readings from any load measurement devices <NUM> generating outlier readings are not monitored in the "Train Operating" mode, to avoid inaccurate or constant alerts.

Once the train consist <NUM> is underway, the PWG <NUM> receives notice of any "Threshold <NUM>" crossing events, i.e., changes in the brake-force readings that cross Threshold <NUM>. These notices are provided to the PWG <NUM> by the load measuring devices <NUM>, via their associated CMUs <NUM>. When such an event occurs in a particular railcar <NUM>, the PWG <NUM> sets a timer for a predetermined time period, e.g., <NUM> minutes, and tracks whether any similar threshold crossing events occur in other railcars <NUM> within that time period. For example, if a predetermined minimum percentage of railcars <NUM>, e.g., <NUM> percent, register a "Threshold <NUM>" crossing event, any railcars <NUM> that do not register a Threshold <NUM> event are flagged by the PWG <NUM> as having brakes that potentially may be non-functioning or malfunctioning. Also, if any particular railcar <NUM> registers a certain number of "Threshold <NUM>" crossing events, e.g., <NUM> crossing events, in the current "Train Operating" mode without the other railcars <NUM> in the consist <NUM> registering similar threshold crossings at about the same times, a more definitive flag and/or alert is provided to the operator via the display <NUM>. The flag or alert can be, for example, a visual indication on the display <NUM>, such as "Brakes Need Inspection. " Additionally, the railcar name or other identifying data, and the time and location of the incident(s) can be logged and displayed to the operator.

The systems 10a, 10b also can be configured to operate in an "Electronic Brake Test" mode. This mode permits the train operator to test the brakes while the train consist <NUM> is not in motion, and to receive the results of the test via the display <NUM>. Unlike the "Train Operating" mode, which may be enabled by the operator or other user for the duration of a specific trip, the "Electronic Brake Test" mode is enabled for a relatively short period of time, e.g., <NUM> minutes, while the train consist <NUM> is not in motion.

During the electronic brake test, the PWG <NUM> first identifies a total count of train-based network-enabled railcars <NUM> having fully-operational CMUs <NUM> and/or WSNs <NUM>. A list manifest of the railcars <NUM> in the train consist <NUM>, a list of railcars <NUM> requiring maintenance, etc., can be provided to the operator via the display <NUM>. The PWG <NUM> then confirms whether the brake-force readings from all of the load measuring devices <NUM> are in the same threshold state, i.e., above or below "Threshold <NUM>" state. In this non-mobile state, any railcars <NUM> generating outlier readings are flagged for inspection or maintenance. Force readings from the load measurement devices <NUM> generating outlier readings are not monitored in the "Electronic Brake Test" mode, to avoid inaccurate or constant alerts.

Next, the operator is prompted, via the display <NUM> or the remote operations center, to charge the braking system so that the air pressure within the brake pipe <NUM> is within <NUM> percent of its regulated value, to facilitate release of the brakes. The brake-force readings from all of the load measuring devices <NUM> are then checked to determine whether the readings are below the "Threshold <NUM>" value, indicating that brakes have been released. After a predetermined period of time, e.g., <NUM> minutes, any railcars <NUM> generating brake force measurements that are not below the "Threshold <NUM>" state are flagged and/or reported for further inspection.

Next, the operator is prompted, via a notification on the display <NUM> or from the remote operations center, to make a "minimum reduction" in brake pressure, e.g., <NUM> psi, to initiate actuation of the brakes. After this minimum reduction is made, the brake force readings from all of the load measuring devices <NUM> are checked to determine whether the readings have moved above the "Threshold <NUM>" state, indicating that the airbrakes of the railcars <NUM> have become actuated. After another predetermined period of time, e.g., two minutes, any railcars <NUM> having brake force readings that are not above the "Threshold <NUM>" value are flagged and/or reported for further inspection.

Upon completion of the "minimum reduction" test, the operator is prompted to make a "full service reduction" in brake pressure, e.g., an additional <NUM> psi, after which all of the brake force readings are checked to determine whether they are above a predetermined "Threshold <NUM>" value, indicating that the brakes have become properly set. After a predetermined period of time, e.g., two minutes, any railcars <NUM> having brake force readings that still are below the "Threshold <NUM>" value are flagged and/or reported for further inspection.

The operator is then prompted to wait an additional period of time, e.g., three minutes, after which the brake force readings are again checked to determine whether the readings are above the "Threshold <NUM>" value. The failing railcars <NUM>, those with readings below the "Threshold <NUM>" value, are flagged and/or reported for further inspection.

Next, the operator is prompted to charge the braking system so that the air pressure within the brake pipe <NUM> is within <NUM> percent of its regulated value, to facilitate release of the brakes, after which the brake force readings from all of the load measuring devices <NUM> are checked to determine whether they are below the "Threshold <NUM>" state, indicating that the brakes have been released. After another predetermined period of time, e.g., <NUM> minutes, any railcars <NUM> generating brake force readings that are not below the "Threshold <NUM>" state are flagged and/or reported for further inspection.

When the "Electronic Brake Test" is completed, all or a portion of the results can be displayed to the operator on the display <NUM> within the locomotive <NUM>. For example, any railcars <NUM> that did not pass any stage of the "Electronic Brake Test" can be listed on the display, with each failed railcar <NUM> identified along with the stage and step(s) at which the failure occurred, the time of failure, etc. Statistics of the test results also can be displayed and/or transmitted to a remote operations center. These statistics can include, for example, information about the operator who conducted the test; the time and duration of the test; the number and identities of the railcars <NUM> tested; the numbers and identities of the railcars <NUM> that passed and failed; the percentage of railcars <NUM> that passed and failed, etc. If a predetermined percentage, e.g., <NUM> percent, or greater of the railcars <NUM> pass the "Electronic Brake Test," the display <NUM> can indicate to the operator that the train consist <NUM> passed the brake test; for example, the message "Overall Test Passed" can be displayed in green on the display <NUM> under such circumstances. With such an electronic test mode that permits the braking systems of all of the railcars <NUM> in the train consist <NUM> to be tested automatically or semi-automatically, on a collective basis, in a relatively short period of time, manual tests of the brake system of each individual railcar <NUM> can be conducted less frequently because the manual testing can be reduced or replaced by this quicker, more reliable, and automated brake test, allowing the railcars <NUM> to operate more frequently and with less downtime.

<FIG> and <FIG> schematically depict other variants of the electronic brake-monitoring system <NUM> in the form of an electronic brake monitoring system 10c and an electronic brake monitoring system 10d, respectively. The "advanced" electronic brake monitoring system 10c and the "full/complete" brake monitoring system 10d include, in addition to one or more of the load measuring sensors <NUM> as described above in relation to the systems 10a, 10b, one or more brake pressure sensors.

As shown in <FIG>, the brake monitoring system 10c includes a single brake pressure sensor. The brake pressure sensor can be, for example, the pressure sensor <NUM> described above; other types of pressure sensors can be used in the alternative. As noted above, the pressure sensor <NUM> includes both an analog sensor and a digital switch. The pressure sensor <NUM> associated with each railcar <NUM> is mounted on the section of brake pipe <NUM> on that particular railcar <NUM>. The addition of the brake pressure sensor <NUM> in the system 10c allows the system 10c to logically differentiate between braking applied by the air brake system of the railcar <NUM> and braking applied by the hand brake <NUM>, without the need to measure the chain tension within the hand brake <NUM> using the handbrake sensor <NUM> of other suitable means.

The brake monitoring system 10d includes a plurality of brake pressure sensors and brake force sensors; and also includes other types of sensors. These other sensors can include, for example, the hand brake sensor <NUM>, the cylinder position sensor <NUM>, and the wheel temperature sensor <NUM> described above. The brake pressure sensors and the brake force sensors can be, for example, the respective pressure sensors <NUM> and load measuring devices <NUM> described above. The additional sensors of the system 10d increase the amount, and the types of data available to monitor the status of the brake systems <NUM> of the railcars <NUM>, and as discussed below, facilitate additional diagnostic testing, reporting, and alerts that the systems 10a, 10b, 10c are not equipped to provide. Also, although the readings from the cylinder position sensor <NUM> and the wheel temperature sensor <NUM> are not used in the below-described logical operations associated with the system 10d, these readings nevertheless can supplement the information available to the operator and/or the remote railroad operations center regarding the state of the brake system <NUM>. As disclosed herein, the brake monitoring system <NUM> incudes a total of <NUM> sensors; more, or fewer sensors and/or different sensor locations can be used in variants of the system 10d.

The electronic brake monitoring systems 10c, 10d can operate in the "Train Operating" mode and "Electronic Brake Test" mode described above in relation to the systems 10a, 10b. The presence of the additional sensors in the systems 10c, 10d, and particularly the brake pressure sensors <NUM>, however, enables the systems 10c, 10d to provide additional information regarding the status and/or operation of the brake systems <NUM> of the railcars <NUM>, and the ability to logically differentiate between braking applied by the air brake system and braking applied by the hand brake <NUM>. For example, <FIG> include tables that display the logical operations that can be performed by the systems 10c, 10d, using the brake-force values from the load measuring device(s) and the pressure readings from the pressure sensor(s) <NUM>, and other information. The particular values of brake force and air pressure presented in <FIG> are presented for illustrative purposes only; other values for these parameters can be used in the alternative.

<FIG> details, in tabular form, logical operations that can be performed in connection with electronic brake testing and train consist reporting by the systems 10c, 10d. The procedures followed during the electronic brake testing can be substantially the same as, or similar to those discussed above in relation to the systems 10a, 10b; and the potential anomalies identified during this testing, and the resulting reporting and alerts, likewise can be similar to those described in relation to the systems 10a, 10b.

As can be seen in <FIG>, however, the availability of pressure readings from the sensor(s) <NUM> gives the systems 10c, 10d capabilities in addition to those of the systems 10a, 10b. For example, the systems 10c, 10d can identify location of air leak in the air brake system of the train consist <NUM> by comparing the pressure readings obtained from the pressure sensors <NUM> on the various railcars <NUM>, and identifying the point in the train consist <NUM> at which the pressure readings drop by a predetermined amount.

Also, the systems 10c, 10d can validate the assets of the train consist <NUM> by verifying that the railcars <NUM> on the manifest register pressure reductions in response to the first pressure reduction during the electronic braking test. In addition, the systems 10c, 10d can validate the consist order by timestamping the exact time of first pressure reduction during the electronic braking test; and comparing the times at which the pressure reduction propagated to each downstream railcar <NUM>, thereby providing the order or the railcars <NUM> within the train consist <NUM>.

<FIG> details, in tabular form, the logical operations that can be performed in connection with a train securement audit and hand brake damaging events testing. These diagnostic activities require knowledge of whether the hand brake <NUM> is set, and therefore can be performed by the systems 10c, 10d, which, as noted above, can make the logical differentiation between braking applied by the air brake system and braking applied by the hand brake.

As shown in <FIG>, the system 10d is capable of determining when the hand brake <NUM> is on, i.e., engaged, based on the hand brake-force reading provided by the hand brake sensor <NUM>. The system 10d also can identify an "air over hand brake application," i.e., an event in which the hand brake <NUM> is applied while the airbrakes are engaged. The system 10d recognizes this condition when the train consist <NUM> is stopped; the brake pipe pressure is at a level indicating that the air brakes have been applied; and the hand brake sensor <NUM> registers an increase in hand brake force indicating that the hand brake <NUM> had been applied.

As also can be seen in <FIG>, the systems 10c, 10d can identify railcars <NUM> that have been moved while the hand brake <NUM> is applied. The systems 10c, 10d recognize this condition when the train consist <NUM> begins moving while the brake pipe pressure is at a level indicating that the air brakes have been released; and the load sensing devices <NUM> or the hand brake sensor <NUM> registers a hand brake force above a threshold indicating that the hand brake <NUM> is applied.

<FIG> details, in tabular form, the logical operations that can be performed in connection with detecting causes for line of road failures. As can be seen in <FIG>, the system 10d can identify the location of break in the brake pipe <NUM>, and/or the source of a transient event that caused a UDE brake application. The systems 10c, 10d determine that a UDE brake application has occurred by recognizing that a predetermined, nearly instantaneous drop in brake pipe pressure has occurred, and then locating the source of the drop by comparing timestamped pressure readings from the pressure sensors <NUM> of the railcars <NUM> throughout the train consist <NUM>.

As also can be seen in <FIG>, the systems 10c, 10d can identify the railcar <NUM> responsible for the UDE brake application by identifying the time at which a sustained reduction in brake pipe pressure below a predetermined threshold occurred, and identifying the railcar <NUM> associated.

Thus, as detailed in tables of <FIG>, utilization of both brake pressure sensor(s) and brake force sensor(s), either alone or in combination, can facilitate more extensive diagnostics, reporting, and alerts than the use of brake force sensors alone, and can facilitate the determination and display of more than just brake-system malfunctions or failures.

<FIG> respectively depict the brake monitoring systems 10a, 10b, 10c, 10d incorporated into the brake system 100a having truck mounted brake rigging.

Various diagnostic, alerting, and reporting capabilities of the brake monitoring systems 10a, 10b, 10c, 10d are displayed in tabular form in <FIG>. Specifically, these tables list the capabilities of, and denote the particular diagnostic, alerting, and reporting functions that can be performed by a "Brake Monitoring Minimum" system, i.e., the system 10a; a "Brake Monitoring Basic" system, i.e., the system 10b; a "Brake Monitoring Advanced" system, i.e., the system 10c; and a "Brake Monitoring Full/Complete" system, i.e., the system 10d. This listings in these tables are presented for illustrative purposes only, and are not limiting, as each of the brake monitoring systems 10a, 10b, 10c, 10d can have capabilities that at not listed in FIGS.

As can be seen in Tables 23A-F, the systems utilizing more sensors, and more different types of sensors, generally provide more extensive diagnostic, alerting, and reporting capabilities.

Table 23A details the diagnostic, alerting, and reporting actions that can be performed before the train consist <NUM> departs a rail yard. As can be seen from Table 23A, all of the systems <NUM>, 10a, 10b, 10c have the capability to identify the location of an air leak in the airbrake system <NUM> so that a targeted inspection can be performed. All of these systems also have the capability to identify any railcar <NUM> or locomotive <NUM> with a brake issue, and to automatically generate a maintenance request so that a brake inspection can be conducted prior to departure. All of the noted systems also have the capability to confirm that the hand brakes <NUM> of all the railcars <NUM> in the train consist <NUM> have been released prior to departure.

Table 23A also indicates that only the systems 10c, 10d, as a result of their additional sensing and data-processing capabilities described above, have the additional capability to perform, from the locomotive <NUM>, an electronic test of the brake system <NUM> sufficient to act as an acceptable alternative process to the standard Class 1A brake test defined in <NUM> CFR <NUM> - Class 1A brake test-initial terminal inspection, i.e., use of the systems 10c, 10d can eliminate the need to conduct the noted test prior to every departure of the train consist <NUM>.

As further indicated by Table 23A, only the systems 10c, 10d have the capability to confirm which railcars <NUM> are in the train consist <NUM> during an electronic air brake test and, based on this information, inform railroad dispatch of any discrepancies in the train manifest, such as out of route railcars. Also, only the systems 10c, 10d have the capability to validate the consist order and inform railroad dispatch of the confirmation.

Table 23B details the diagnostic, alerting, and reporting actions that can be performed during, or immediately after a line of road undesired emergency (UDE) brake application. As can be seen from this table, only the systems 10c, 10d, as a result of their additional sensing and data-processing capabilities described above, have the capability to identify the location of a break in the train air line, i.e., the air pipe <NUM>, so that a targeted inspection can be performed. Table 23B also indicates that only the systems 10c, 10d have the capability to identify the source location of a transient event causing the UDE brake application, so that an operations review can be conducted. As also can be seen from Table 23B, only the systems 10c, 10d can identify the locomotive <NUM> or railcar <NUM> responsible for the UDE brake application and automatically generate a maintenance request, so that an inspection of the locomotive <NUM> or railcar <NUM> can be conducted.

Table 23C details the diagnostic, alerting, and reporting actions that can be performed during securement of the train consist <NUM> inside or outside of a railyard. As can be seen from Table 23C, only the systems 10c, 10d, as a result of their additional sensing and data-processing capabilities described above, have the capability to confirm the status of both the air brake system and the hand brake <NUM> on each railcar <NUM> before the train operator leaves the train consist <NUM> unattended, and to report the status to the train operator and train dispatch.

As also can be seen from Table 23C, only the systems 10c, 10d have the capability to identify the track grade, i.e., slope, on which the train consist <NUM> is located; to calculate the minimum number of hand brakes <NUM> in the train consist <NUM> that need to secured, i.e., applied, for that particular grade; count the number of hand brakes <NUM> that have been secured; confirm proper securement of the train consist <NUM> based on the status of the hand brakes <NUM>; report to the train operator and dispatch when the number of applied hand brakes <NUM> exceeds the minimum required for the grade; and confirm the status of all the hand brakes <NUM> before the train operator leaves the train consist <NUM> unattended.

Table 23C also indicates that only the systems 10c, 10d have the capability to confirm the operating practice of securing a train with the hand brakes <NUM>; this information subsequently can be used for safety and compliance audits.

Table 23D details the diagnostic, alerting, and reporting actions that can be performed during operation of the train consist <NUM>. As can be seen from Table 23D, all of the systems 10a, 10b, 10c, 10d have the capability to confirm, while the train consist <NUM> is in motion, that the train consist <NUM> has effective airbrakes.

Table 23D also shows that all of the systems 10a, 10b, 10c, 10d can identify specific railcars <NUM> exhibiting low air-braking force, and automatically generate a maintenance request to facilitate maintenance at the next available maintenance opportunity.

As also can be seen from Table 23D, only the systems 10b, 10c, 10d, as a result of their additional sensing and data-processing capabilities described above, can electronically test the airbrake system of train consist <NUM> from the locomotive <NUM>, in a manner sufficient to allow such testing to be performed an alternative to, i.e., in lieu of, the standard Class 1A brake test as defined <NUM> CFR <NUM> - Class 1A brake test-Intermediate inspection. Current regulations require that the Class 1A brake test-Intermediate inspection test be performed after every <NUM>,<NUM> miles of travel of the train consist <NUM>. It has been estimated by railroad operators that eliminating the need for this particular test can save between <NUM> and <NUM> minutes of operating time during every <NUM>,<NUM>-mile leg of travel of the train consist <NUM>.

As indicated in Table 23D, only the systems 10a, 10b, 10c have the capabilities to electronically test, from the locomotive <NUM>, for "cold wheel railcars," i.e., individual railcars <NUM> on which the braking was not applied during a braking event of the train consist <NUM>.

Table 23D also shows that only the systems 10c, 10d, as a result of their additional sensing and data-processing capabilities described above, have the capability to identify the location of a break in the brake pipe <NUM>, such as a broken air hose; or the weakest brake valve <NUM>, following a UDE brake application, so that an appropriate inspection can be conducted. Table 23D further indicates that only the systems 10c, 10d have the capability to identify individual railcars <NUM> that were moved with their hand brake <NUM> applied. Identifying such railcars <NUM> permits any resulting wheel damage to be correlated to the incorrect hand-brake application; and can be used to educate the responsible parties to prevent future damage, and/or to bill responsible parties for any resulting damages.

Table 23E details the diagnostic, alerting, and reporting actions that can be performed during maintenance of the train consist <NUM>. As can be seen from Table 23E, all of the systems 10a, 10b, 10c, 10d have the capability to identify, and report railcars that have properly operating brakes. This feature can reduce the number of scheduled brake tests (SCABTs) that are performed unnecessarily. Table 23E also shows that the systems 10a, 10b, 10c, 10d can generate and provide a report identifying railcars <NUM> that have improperly-operating and/or non-effective brakes, so that necessary testing and maintenance can be properly targeted.

Table 23E further indicates that all of the systems 10a, 10b, 10c, 10d also have the capability to generate and provide a report of individual railcars <NUM> exhibiting low brake force, and to automatically generate a maintenance request so that necessary testing and maintenance can be properly targeted.

Table 23E also indicates that only the systems 10c, 10d, as a result of their additional sensing and data-processing capabilities described above, have the capability to generate and provide a report of individual railcars <NUM> that were moved with the hand brake <NUM> applied. Such reports can be used to properly target necessary inspections and maintenance of the affected wheels, and to bill the responsible parties for damages. Table 23E also shows that only the systems 10c, 10d have the capability to generate and supply a report of railcars that have experienced an "air over hand brake" application, i.e., the application of air braking while the hand brake <NUM> is applied. These reports can be used to properly target necessary inspections and maintenance of the affected wheels, and to bill the responsible parties.

As also can be seen from <FIG>, only the system 10d, as a result of its additional sensing and data-processing capabilities described above, has the capability to identify which specific part of the brake system <NUM> of a railcar experienced a malfunction, i.e. the brake valve <NUM>, brake cylinder <NUM>, slack adjuster <NUM>, etc. This information can be used to perform a targeted repair of the affected component(s).

Claim 1:
A system for detecting the operational status of a brake system on a railcar of a train consist, the system comprising:
a sensor (<NUM>) located on the railcar and configured to generate an output indicative of a magnitude of a braking force applied by the braking system; and
a computing device (<NUM>) communicatively coupled to the sensor and comprising a computer-readable storage medium comprising one or more programming instructions that, when executed, cause the computing device to:
receive from the sensor an indication of the magnitude of a braking force applied by the braking system in response to an instruction to increase or decrease the braking force;
compare the response to possible responses of the braking system to the instruction to increase or decrease the braking force; and
based on the comparison, generate at least one of a message and an alert indicating the status of the brake system,
the system further comprising:
a pressure sensing device (<NUM>) communicatively coupled to the computing device and configured to measure air pressure within a brake pipe of the railcar,
wherein the pressure sensing device (<NUM>) comprises an analog pressure sensor and digital pressure switch, where the pressure sensor is configured to begin sampling the air pressure when the digital pressure switch senses an increase or decrease in the air pressure above or below a predetermined threshold.