Fluid control system, brake system, and abnormality determination system

Abstract

The present application provides a fluid control system, a brake system, and an abnormality determination system. Control is continued even in a case where an abnormality has occurred in a sensor used for feedback control. The fluid control system includes a device that controls a fluid flowing in a flow path, a first sensor provided at a portion upstream of the device, and a second sensor provided at a portion downstream of the device. The fluid control system performs processing based on a measurement value of a reference sensor that is one of the first sensor and the second sensor. The fluid control system includes an abnormality determination section, an estimation section, and a processing section. The abnormality determination section determines whether or not the reference sensor has an abnormality. The estimation section calculates an estimated value of the measurement value of the reference sensor based on a characteristic of the device and on a measurement value of a sensor that is not the reference sensor among the first sensor and the second sensor. In a case where it is determined that the reference sensor has an abnormality, the processing section performs processing using the estimated value.

Description

Technical Field

[0001] This invention relates to a fluid control system, a braking system, and an anomaly detection system. Background Technology

[0002] Air brakes are used in railway vehicles. Patent Document 1 describes a feedback control method for an air brake. Patent Document 1 discloses a technique for performing feedback control to ensure that the output pressure of the solenoid valve (commonly used control valve) that generates the pilot pressure of the air brake matches the pressure represented by the pressure command signal.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 10-035478 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] The feedback control described in Patent Document 1 is based on the pilot pressure of an air brake; therefore, if the sensor detecting the pilot pressure malfunctions, control cannot be performed. Not limited to air brakes, in systems that control fluids via feedback control, control may fail due to sensor malfunctions.

[0008] The purpose of this invention is to provide a fluid control system, braking system, and anomaly detection system that can continue to control even when a sensor used for feedback control malfunctions.

[0009] Solution for solving the problem

[0010] According to a first embodiment, the fluid control system includes: a device that controls a fluid flowing in a flow path; a first sensor disposed upstream of the device in the flow path for measuring a state quantity related to the fluid flowing into the device; a second sensor disposed downstream of the device in the flow path for measuring the state quantity related to the fluid flowing out of the device; and a processing unit that performs processing based on measurements from a reference sensor that serves as one of the first and second sensors.

[0011] An anomaly determination unit determines whether the reference sensor is abnormal; and an estimation unit calculates an estimated value of the reference sensor's measurement value based on the characteristics of the device and the measurement values ​​of the first sensor and the second sensor that are not the reference sensor, wherein, if it is determined that the reference sensor is abnormal, the processing unit uses the estimated value to perform the processing.

[0012] According to the second approach, in the fluid control system involved in the first approach, the fluid control system is installed on the railway vehicle, and the processing unit controls the brakes of the railway vehicle based on the measured value or the estimated value.

[0013] According to the third approach, in the fluid control system involved in the first or second approach, the fluid is air, and the state quantities measured by the first sensor and the second sensor are the pressure or flow rate of the air.

[0014] According to the fourth approach, the device may also be a valve in the fluid control system involved in any of the first to third approaches.

[0015] According to the fifth approach, or in the fluid control system involved in the fourth approach, the device is a flow amplification valve.

[0016] According to the sixth method, a braking system is installed in a railway vehicle, the braking system comprising: an air brake that operates using air supplied from an air source through a flow path; a pilot pressure generating unit disposed in the flow path for generating a pilot pressure for the air brake using air supplied from the air source; a valve disposed in the flow path between the pilot pressure generating unit and the air brake; a first sensor disposed in the flow path between the valve and the pilot pressure generating unit for measuring the state quantity of air flowing into the valve; and a second sensor disposed in the flow path between the valve and the air brake for... The system includes: a measurement unit for the state quantity of air flowing out of the valve; a processing unit that performs feedback control of the pilot pressure generation unit based on the measurement value of a reference sensor (which is one of the first and second sensors) and the target pressure of the air brake; an anomaly determination unit that determines whether the reference sensor is abnormal; and an estimation unit that calculates an estimated value of the measurement value of the reference sensor based on the characteristics of the valve and the measurement value of a sensor that is not the reference sensor among the first and second sensors, wherein, if it is determined that the reference sensor is abnormal, the processing unit uses the estimated value to perform the feedback control.

[0017] According to the seventh method, in the braking system involved in the sixth method, if the difference between the measured value and the estimated value of the reference sensor is lower than a threshold for a specified period of time, the anomaly determination unit determines that the reference sensor has an abnormal disappearance, and after determining that the reference sensor has an abnormal disappearance, the processing unit performs processing based on the measured value of the reference sensor.

[0018] According to the eighth method, the braking system involved in the sixth or seventh method may also include a notification unit that notifies of an anomaly when the anomaly determination unit determines that the reference sensor is abnormal.

[0019] According to the ninth method, the anomaly determination system comprises: a valve unit having a device, a first sensor, and a second sensor, wherein the device controls fluid flowing in a flow path, the first sensor is disposed upstream of the device in the flow path for measuring a state quantity related to the fluid flowing into the device, and the second sensor is disposed downstream of the device in the flow path for measuring the state quantity related to the fluid flowing out of the device; an estimation unit that, based on the characteristics of the device, calculates an estimated value of the measurement value of the other sensor based on the measurement value of one of the first and second sensors; and an anomaly determination unit that determines whether the valve unit is abnormal based on the deviation between the measurement value of the other sensor and the estimated value of the other sensor.

[0020] According to the tenth method, a braking system installed on a railway vehicle includes: an air brake that operates using air supplied from an air source through a flow path; a pilot pressure generating unit disposed in the flow path that generates a pilot pressure for the air brake using air supplied from the air source; a valve unit comprising a valve, a first sensor, and a second sensor, wherein the valve is disposed in a portion of the flow path between the pilot pressure generating unit and the air brake, the first sensor is disposed in a portion of the flow path between the valve and the pilot pressure generating unit for measuring the pressure of air flowing into the valve, and the second sensor is disposed in a portion of the flow path between the valve and the air brake for measuring the pressure of air flowing out of the valve; an estimation unit that, based on the characteristics of the valve, calculates an estimated value of the measured value of the other sensor based on the measured value of one of the first and second sensors; and an anomaly determination unit that determines whether the valve unit is abnormal based on the deviation between the measured value of the other sensor and the estimated value of the other sensor.

[0021] Invention Effects

[0022] According to at least one of the above methods, the fluid control system, braking system, and anomaly detection system can continue to control even if the sensor used for feedback control malfunctions. Attached Figure Description

[0023] Figure 1 This is a schematic diagram showing the structure of the braking system according to the first embodiment.

[0024] Figure 2 This is a schematic block diagram showing the structure of the controller according to the first embodiment.

[0025] Figure 3 This is a flowchart illustrating the control method (part 1) of the braking system according to the first embodiment.

[0026] Figure 4 This is a flowchart illustrating the control method (part 2) of the braking system according to the first embodiment.

[0027] Figure 5 This is a schematic block diagram showing the structure of the braking system according to the second embodiment.

[0028] Figure 6 This is a flowchart illustrating the method for determining anomalies in the air brake performed by the controller according to the second embodiment. Detailed Implementation

[0029] (First Implementation)

[0030] The embodiments will now be described in detail with reference to the accompanying drawings.

[0031] <Structure of the Braking System>

[0032] Figure 1 This is a schematic diagram showing the structure of the braking system according to the first embodiment. The braking system 1 according to the first embodiment is installed in a railway vehicle.

[0033] The braking system 1 includes an air tank 101, a general control valve 102, multiple air springs 103, a variable load valve 104, an emergency solenoid valve 105, a relay valve 106, a brake cylinder 107, a brake setter 108, an AC pressure sensor 109, a BC pressure sensor 110, multiple variable load sensors 111, and a controller 112.

[0034] Air tank 101 is an air source that holds compressed air generated by a compressor (not shown).

[0035] The general-purpose control valve 102 receives a control signal from the controller 112 and, according to the control signal, discharges a portion of the compressed air supplied from the air tank 101 to reduce pressure, thereby generating pilot air. The pressure of the pilot air is also referred to as the AC (Application Chamber) pressure. The general-purpose control valve 102 supplies pilot air to the relay valve 106. The general-purpose control valve 102 is an example of a pilot pressure generation unit.

[0036] An air spring 103 is installed on the floor of the railway vehicle. The air pressure inside the air spring 103 varies according to the applied load. That is, the air pressure of the air spring 103 corresponds to the variable load. The air spring 103 is connected to a variable load valve 104, and the air pressure of the air spring is transmitted to the variable load valve 104.

[0037] The variable load valve 104 receives air pressure from multiple air springs 103 and supplies the emergency solenoid valve 105 with the pressure of compressed air supplied from the air tank 101 after changing the pressure to a pressure corresponding to the variable load.

[0038] The emergency solenoid valve 105 switches whether to supply compressed air from the variable load valve 104 to the relay valve 106. The emergency solenoid valve 105 is electrically connected to the emergency braking command line and is controlled according to the emergency braking command.

[0039] Relay valve 106 supplies compressed air from air tank 101 at a pressure consistent with the AC pressure output from the normal control valve 102 to brake cylinder 107. Relay valve 106 is an example of a device for controlling the flow of fluid in a flow path. The flow rate of compressed air (control air) supplied by relay valve 106 is greater than the flow rate of pilot air supplied by normal control valve 102. That is, relay valve 106 is a flow amplification valve that generates control air to amplify the flow rate while maintaining the pilot air pressure. The pressure of the control air output by relay valve 106 is also referred to as BC (Brake Cylinder) pressure.

[0040] In addition, when the relay valve 106 is supplied with compressed air from the emergency solenoid valve 105, it supplies control air according to the pressure of the compressed air supplied from the emergency solenoid valve 105, regardless of the AC pressure.

[0041] The relay valve 106 has two air chambers (AC chamber and BC chamber) separated by a diaphragm. A pilot port for pilot air inflow is provided in the AC chamber. A first port communicating with the air tank 101 and a second port communicating with the brake cylinder 107 are provided in the BC chamber. The pressure in the AC chamber is maintained at AC pressure by the pilot air, pressing the diaphragm in a manner that balances the pressures in the BC and AC chambers. Due to this structure, the BC pressure becomes close to the AC pressure. Furthermore, the construction of the relay valve 106 in other embodiments is not limited to the structure described above, but the commonality is that the pressures are balanced between the air chamber for pilot air inflow and the air chamber for control air outflow.

[0042] Furthermore, the BC pressure and AC pressure are not completely consistent; the BC pressure P BC With AC pressure P ACThe following relationship, Equation (1), is used with gain A and offset B. Equation (1) represents the characteristics of relay valve 106.

[0043] P BC =A×P AC +B…(1)

[0044] The brake cylinder 107 operates according to the pressure of the control air supplied from the relay valve 106 to actuate a caliper brake (not shown). The actuation of the caliper brake generates braking force on the railway vehicle.

[0045] The brake setting device 108 is an operating device used by the driver of a railway vehicle to instruct the target deceleration of the railway vehicle. By operating the brake setting device 108, a braking command representing the target deceleration is input to the controller 112.

[0046] AC pressure sensor 109 measures the AC pressure output from the common control valve 102 and generates an electrical signal corresponding to the AC pressure. AC pressure sensor 109 is an example of a first sensor located upstream of relay valve 106 in the flow path, used to measure state quantities related to the pilot air flowing into relay valve 106. AC pressure sensor 109 is also an example of a reference sensor used for feedback control of the air brake. A reference sensor is a sensor that references measured values ​​for processing performed by controller 112.

[0047] The BC pressure sensor 110 measures the BC pressure output from the relay valve 106 and generates an electrical signal corresponding to the BC pressure. The BC pressure sensor 110 is an example of a second sensor located downstream of the relay valve 106 in the flow path, used to measure state quantities related to the control air flowing out of the relay valve 106.

[0048] The variable load sensor 111 measures the air pressure of the air spring 103 and generates an electrical signal corresponding to the air pressure. Since the air pressure corresponds to the variable load, the electrical signal output by the variable load sensor 111 represents the variable load.

[0049] The controller 112 outputs a control signal to control the opening degree of the common control valve 102 based on the target deceleration represented by the braking command of the brake setter 108 and the electrical signals input from the AC pressure sensor 109, BC pressure sensor 110 and variable load sensor 111.

[0050] <Controller 112 of Braking System 1>

[0051] The controller 112 according to the first embodiment controls the brake cylinder 107 using feedback control from the AC pressure sensor 109. On the other hand, in the event of a malfunction in the AC pressure sensor 109, the BC pressure sensor 110 is used instead to control the brake cylinder 107, thereby improving availability. Furthermore, in the event of a malfunction in both the AC pressure sensor 109 and the BC pressure sensor 110, the brake cylinder 107 is activated via the emergency solenoid valve 105.

[0052] Figure 2 This is a schematic block diagram showing the structure of the controller 112 according to the first embodiment. The controller 112 according to the first embodiment includes a signal input unit 201, a sensor anomaly determination unit 202, a conversion unit 203, a braking force determination unit 204, a feedback control unit 205, a signal output unit 206, a brake anomaly determination unit 207, a status storage unit 208, and a notification unit 209.

[0053] The signal input unit 201 receives electrical signal input from the brake setter 108, AC pressure sensor 109, BC pressure sensor 110 and variable load sensor 111.

[0054] The sensor anomaly determination unit 202 determines whether the AC pressure sensor 109, BC pressure sensor 110, and variable load sensor 111 are abnormal based on the electrical signals input from them. The sensor anomaly determination unit 202 according to the first embodiment determines whether the sensor has a broken wire or a short circuit fault. Specifically, the sensor anomaly determination unit 202 determines a broken wire fault when the voltage value of the electrical signal is lower than a broken wire threshold (e.g., 0.5V), and determines a short circuit fault when the voltage value of the electrical signal is higher than a short circuit threshold (e.g., 4.8V).

[0055] The conversion unit 203 converts the measured value of the BC pressure sensor 110 (BC pressure output from the relay valve 106) into the value of the AC pressure sensor 109 (AC pressure input to the relay valve 106) based on the above formula (1).

[0056] The braking force determination unit 204 determines the target braking force based on electrical signals from the brake setter 108 and the variable load sensor 111, in a manner that obtains a certain deceleration. Specifically, the braking force determination unit 204 determines the target braking force based on the product of the deceleration set by the brake setter 108 and the load measured by the variable load sensor 111. The braking force determination unit 204 determines the target AC pressure based on the target braking force.

[0057] The feedback control unit 205 calculates the correction value (feedback amount) involved in the feedback control in such a way as to reduce the difference between the AC pressure represented by the measurement value of the AC pressure sensor 109 or the AC pressure calculated based on the measurement value of the BC pressure sensor 110 and the previous command value of the commonly used control valve 102.

[0058] The signal output unit 206 outputs the control signal of the common control valve 102 based on the value obtained by subtracting the feedback amount from the target AC pressure determined by the braking force determination unit 204.

[0059] The brake malfunction determination unit 207 compares the BC pressure required to exert the target braking force with the BC pressure measured by the BC pressure sensor 110 to determine whether the air brake has any malfunctions related to insufficient air or failure to release. For example, if the BC pressure measured by the BC pressure sensor 110 is lower than the insufficient air threshold for a certain period of time, the brake malfunction determination unit 207 determines that the air brake is insufficient. Conversely, if the BC pressure measured by the BC pressure sensor 110 is higher than the failure to release threshold for a certain period of time, the brake malfunction determination unit 207 determines that the air brake is not releasing.

[0060] The state storage unit 208 stores the operating state of the feedback control. The operating state of the feedback control is either "normal" or "emergency". "Normal" is the state in which feedback control is performed using the AC pressure sensor 109, and "emergency" is the state in which feedback control is performed using the value of the AC pressure sensor 109 calculated from the BC pressure sensor 110. The initial value of the operating state stored in the state storage unit 208 is "normal".

[0061] If any of the AC pressure sensor 109, BC pressure sensor 110, and variable load sensor 111 is determined to be malfunctioning, the notification unit 209 notifies the driver of the malfunction. The notification unit 209 notifies the driver of the malfunction, for example, by using a buzzer or illuminating a light.

[0062] <Control Method of Braking System 1>

[0063] Figure 3 This is a flowchart illustrating the control method (part 1) of the braking system 1 according to the first embodiment. Figure 4 This is a flowchart illustrating the control method (part 2) of the braking system 1 according to the first embodiment.

[0064] The controller 112 of the braking system 1 according to the first embodiment repeats its operation at predetermined control cycles when the braking system 1 is running. Figure 3 The processing shown.

[0065] First, the signal input unit 201 of the controller 112 receives electrical signal input from the brake setter 108, AC pressure sensor 109, BC pressure sensor 110, and variable load sensor 111 (step S1). The sensor anomaly determination unit 202 determines whether an anomaly exists for each of the AC pressure sensor 109, BC pressure sensor 110, and variable load sensor 111 based on the electrical signals input from them (step S2). If an anomaly is determined to exist in any of the AC pressure sensor 109, BC pressure sensor 110, and variable load sensor 111, the notification unit 209 notifies the driver of the anomaly.

[0066] The braking force determination unit 204 determines the target AC pressure for exerting the desired target braking force based on electrical signals from the brake setter 108 and the variable load sensor 111 (step S3). Furthermore, in the event of an anomaly in the variable load sensor 111, the braking force determination unit 204 uses a pre-determined guaranteed load value to determine the target AC pressure.

[0067] Next, the sensor anomaly determination unit 202 determines whether the value of the operating state stored in the state storage unit 208 is "normal" (step S18). If the value of the operating state is "normal" (step S18: "Yes"), the sensor anomaly determination unit 202 determines whether the AC pressure sensor 109 was determined to be abnormal in step S2 (step S5). If the AC pressure sensor 109 is determined to be normal (step S5: "No"), the feedback control unit 205 calculates the feedback quantity in a way that reduces the difference between the AC pressure represented by the measured value of the AC pressure sensor 109 and the previous command value of the normal operating control valve 102 (step S6).

[0068] On the other hand, if it is determined in step S2 that the AC pressure sensor 109 is malfunctioning (step S5: "Yes"), the sensor malfunction determination unit 202 determines whether the BC pressure sensor 110 is malfunctioning (step S7). If it is determined in step S2 that the BC pressure sensor 110 is not malfunctioning (step S7: "No"), the sensor malfunction determination unit 202 rewrites the operating state stored in the state storage unit 208 to "Emergency" (step S8). The conversion unit 203 converts the measured value of the BC pressure sensor 110 into AC pressure based on the above formula (1) (step S9). The feedback control unit 205 calculates the feedback quantity in a way that reduces the difference between the converted value of the AC pressure and the previous command value of the normal control valve 102 (step S10).

[0069] In step S18, if the application status is "emergency" (step S18: "No"), the conversion unit 203 converts the measured value of the BC pressure sensor 110 into AC pressure based on the above formula (1) (step S11). Next, the sensor anomaly determination unit 202 determines whether the AC pressure sensor 109 is abnormal as determined in step S2 (step S12).

[0070] If the AC pressure sensor 109 is determined to be malfunctioning (step S12: "Yes"), the sensor malfunction determination unit 202 determines whether the BC pressure sensor 110 is malfunctioning (step S13). If the BC pressure sensor 110 is determined to be malfunctioning (step S13: "No"), the feedback control unit 205 calculates the feedback quantity in a way that reduces the difference between the converted AC pressure value obtained in step S11 and the previous command value of the common control valve 102 (step S14).

[0071] If the AC pressure sensor 109 is determined to be normal (step S12: "No"), the sensor malfunction determination unit 202 determines whether the state in which the difference between the measured value of the AC pressure sensor 109 and the converted value of the AC pressure calculated in step S11 is within a specified range has continued for a certain period of time (step S15). If the difference between the measured value of the AC pressure and the converted value of the AC pressure sometimes exceeds the specified range within a certain period of time (step S15: "No"), the AC pressure sensor 109 may be unstable, therefore the sensor malfunction determination unit 202 maintains the operation state as "emergency". The controller 112 causes the processing to proceed to step S13.

[0072] On the other hand, if the difference between the measured value of AC pressure and the converted value of AC pressure does not exceed the specified range for a certain period of time (step S15: "Yes"), the AC pressure sensor 109 is considered to be stable, and the sensor abnormality determination unit 202 rewrites the operating state stored in the state storage unit 208 to "normal" (step S16). The controller 112 causes the processing to proceed to step S6.

[0073] When the feedback quantity is calculated in step S6, step S10 or step S14, the signal output unit 206 outputs the control signal of the common control valve 102 based on the value obtained by subtracting the feedback quantity from the target AC pressure determined in step S3 (step S17).

[0074] If it is determined that there is an abnormality in both AC pressure sensor 109 and BC pressure sensor 110 (step S7: "Yes" or step S13: "Yes"), the feedback control unit 205 cannot calculate the feedback quantity, so the signal output unit 206 does not output the control signal of the common control valve 102 (step S18).

[0075] Furthermore, the above-described processing order is just one example; the order of some processes can be reversed, or the calculations can be performed in parallel. For example, in the first embodiment, the conversion from BC pressure to AC pressure in step S7 is performed if the BC pressure sensor 110 is not malfunctioning. However, in other embodiments, the conversion can be performed before determining whether the sensor is malfunctioning, or it can be performed regardless of the determination result.

[0076] <Effect>

[0077] Thus, the braking system 1 according to the first embodiment performs feedback control of AC pressure based on the measurement value of AC pressure sensor 109 (reference sensor) located upstream of relay valve 106. In the event of an anomaly in AC pressure sensor 109, the controller 112 of the braking system 1 uses the value of AC pressure sensor 109 estimated based on the measurement value of BC pressure sensor 110 to perform feedback control of AC pressure. Therefore, even if AC pressure sensor 109 is abnormal, the controller 112 can continue brake control using BC pressure sensor 110. Consequently, the controller 112 according to the first embodiment improves the availability of the braking system 1. Examples of devices for controlling fluid flowing in a flow path include valves, actuators, and pumps.

[0078] Furthermore, the braking system 1 according to the first embodiment includes an AC pressure sensor 109 and a BC pressure sensor 110 as pressure sensors for measuring air pressure, but it is not limited to this in other embodiments. For example, the braking system 1 according to other embodiments may also include a flow sensor instead of a pressure sensor. Examples of fluid-related state quantities include pressure, flow rate, density, velocity, acceleration, etc.

[0079] (Second Implementation)

[0080] In the first embodiment, the controller 112 estimates the value of the AC pressure sensor 109 based on the measurement value of the BC pressure sensor 110 to improve the availability of AC pressure feedback control. In contrast, the controller 112 in the second embodiment estimates the value of the BC pressure sensor 110 based on the measurement value of the AC pressure sensor 109. When the BC pressure sensor 110 malfunctions, the controller 112 in the second embodiment uses the BC pressure value estimated based on the measurement value of the AC pressure sensor 109 to determine whether the air brake is insufficient or not releasing.

[0081] Figure 5This is a schematic block diagram showing the structure of the braking system 1 according to the second embodiment. In addition to the structure of the first embodiment, the braking system 1 according to the second embodiment also includes a relay valve sensor 113 for determining whether the relay valve 106 is faulty. When the BC pressure sensor 110 is normal, the brake malfunction determination unit 207 of the controller 112 determines an air brake malfunction based on the measurement value of the BC pressure sensor 110. On the other hand, when the BC pressure sensor 110 malfunctions, the brake malfunction determination unit 207 determines an air brake malfunction based on the BC pressure estimated from the measurement value of the AC pressure sensor 109 and the measurement value of the relay valve sensor 113.

[0082] Figure 6 This is a flowchart illustrating the method for determining anomalies in the air brake performed by the controller 112 according to the second embodiment.

[0083] The controller 112 of the braking system 1 according to the second embodiment repeats its operation every predetermined control cycle when the braking system 1 is running. Figure 6 The processing shown.

[0084] First, the signal input unit 201 of the controller 112 receives electrical signal input from the brake setter 108, the AC pressure sensor 109, and the BC pressure sensor 110 (step S21). The sensor anomaly determination unit 202 determines whether an anomaly exists for each of the AC pressure sensor 109 and the BC pressure sensor 110 based on the electrical signals input from them (step S22). If an anomaly is determined to exist in any of the AC pressure sensor 109, the BC pressure sensor 110, and the variable load sensor 111, the notification unit 209 notifies the driver of the anomaly.

[0085] The sensor malfunction determination unit 202 determines whether the BC pressure sensor 110 is malfunctioning in step S2 (step S23). If the BC pressure sensor 110 is determined to be normal (step S23: "No"), the brake malfunction determination unit 207 determines whether the air brake is malfunctioning, i.e., whether there is insufficient air or failure to release, based on the BC pressure indicated by the measurement value of the BC pressure sensor 110 (step S24).

[0086] On the other hand, if it is determined in step S22 that the BC pressure sensor 110 is abnormal (step S23: "Yes"), the sensor abnormality determination unit 202 determines whether the AC pressure sensor 109 is abnormal (step S25). If it is determined that the AC pressure sensor 109 is not abnormal (step S25: "No"), the conversion unit 203 converts the measured value of the AC pressure sensor 109 into BC pressure based on the above formula (1) (step S26). The brake abnormality determination unit 207 determines whether the air brake is abnormal based on the BC pressure converted from the measured value of the AC pressure sensor 109 and the measured value of the relay valve sensor 113 (step S27). Specifically, if the brake abnormality determination unit 207 determines that the air brake is abnormal when the relay valve 106 is abnormal (air leakage, adhesion, etc.) based on the measured value of the relay valve sensor 113, the air brake is abnormal. Furthermore, if the difference between the BC pressure calculated by the AC pressure sensor 109 and the BC pressure used to exert the desired braking force exceeds a specified range, the brake malfunction determination unit 207 determines that the air brake has malfunctioned.

[0087] If the determination result of step S24 or step S27 indicates that the brake is abnormal (step S28: "Yes"), the notification unit 209 notifies the driver of the brake abnormality (step S29).

[0088] If there is an abnormality in both AC pressure sensor 109 and BC pressure sensor 110, the notification unit 209 notifies the driver that it is impossible to determine the brake abnormality (step S30).

[0089] <Effect>

[0090] Thus, the controller 112 of the braking system 1 according to the second embodiment determines brake malfunction based on the measurement value of the BC pressure sensor 110 (reference sensor) located downstream of the relay valve 106. If the BC pressure sensor 110 is malfunctioning, the controller 112 of the braking system 1 uses the BC pressure value estimated based on the measurement value of the AC pressure sensor 109 to determine brake malfunction. Therefore, even if the BC pressure sensor 110 is malfunctioning, the controller 112 can continue to determine brake malfunction using the AC pressure sensor 109. Consequently, the controller 112 according to the second embodiment improves the availability of the braking system 1.

[0091] (Third Implementation)

[0092] The controller 112 of the braking system 1 described in the above embodiment determines open-circuit and short-circuit faults based on whether the voltage value of the electrical signal is below a disconnection threshold or above a short-circuit threshold for the AC pressure sensor 109 and the BC pressure sensor 110. However, this method is difficult to detect faults such as the voltage value of the electrical signal being stuck between the open-circuit and short-circuit thresholds, or faults such as the voltage value of the electrical signal having an abnormal deviation. The third embodiment can detect abnormalities other than open-circuit and short-circuit faults.

[0093] The structure of the braking system 1 involved in the third embodiment is the same as that in the first embodiment.

[0094] The sensor anomaly determination unit 202 according to the third embodiment determines whether the sensor is abnormal by comparing the measured value of the AC pressure sensor 109 with the AC pressure value calculated by the conversion unit 203 based on the measured value of the BC pressure sensor 110. Specifically, if the difference between the measured value of the AC pressure sensor 109 and the AC pressure value calculated based on the measured value of the BC pressure sensor 110 exceeds a predetermined range for a certain period of time, the sensor anomaly determination unit 202 determines that the valve unit consisting of the AC pressure sensor 109, the relay valve 106, and the BC pressure sensor 110 is abnormal. The valve unit that is subject to determination refers to the range from the location where the AC pressure sensor 109 is installed to the location where the BC pressure sensor 110 is installed in the pneumatic circuit constituting the braking system 1.

[0095] In addition, the sensor anomaly determination unit 202 can also determine whether the sensor is abnormal by comparing the measured value of the BC pressure sensor 110 with the BC pressure value calculated by the conversion unit 203 based on the measured value of the AC pressure sensor 109.

[0096] Furthermore, when the braking system 1 is equipped with the relay valve sensor 113 in the same manner as in the second embodiment, the sensor anomaly determination unit 202 can also determine anomalies based on the measured values ​​of the relay valve sensor 113. With the relay valve sensor 113 included, the sensor anomaly determination unit 202 can determine anomalies in the AC pressure sensor 109 or the BC pressure sensor 110, as well as anomalies in the relay valve 106.

[0097] (Other implementation methods)

[0098] The above description, with reference to the accompanying drawings, details one embodiment. However, the specific structure is not limited to the structure described above, and various design changes are possible. That is, in other embodiments, the order of the above processes can be appropriately altered. Furthermore, some processes can be executed in parallel.

[0099] Regarding the embodiments disclosed in this specification where multiple functions are distributed, some or all of these multiple functions may also be centrally located. Conversely, embodiments where multiple functions are centrally located may be configured to distribute some or all of these multiple functions. Whether the functions are centrally located or distributed, it is acceptable as long as the configuration achieves the purpose of the invention. For example, the controller 112 involved in the embodiments disclosed in this specification may be composed of a single computer, or the structure of the controller 112 may be separately configured on multiple computers, and the multiple computers may cooperate with each other to function as the controller 112.

[0100] In the above-described embodiments, the controller 112, i.e., the fluid controller, controls the air brake, but is not limited thereto. For example, the fluid controllers involved in other embodiments can also control the actuators involved in the hydraulic circuit. Examples of fluids include gases such as air and liquids such as the working oil of the hydraulic circuit.

[0101] Furthermore, the controller 112 described in the above embodiment uses two sensors located upstream and downstream of the relay valve 106 to perform feedback control of the air brake, fault determination of the air brake, and other processing. In contrast, the controller 112 in other embodiments may also use two sensors located upstream and downstream of devices other than the relay valve 106 (e.g., valves, pumps, actuators, etc.) to perform the specified processing.

[0102] (Computer Architecture)

[0103] The controller 112 includes a processor, memory, auxiliary storage device, etc., connected via a bus, and functions as a device having a signal input unit 201, a sensor anomaly determination unit 202, a calculation unit 203, a braking force determination unit 204, a feedback control unit 205, a signal output unit 206, a brake anomaly determination unit 207, a status storage unit 208, and a notification unit 209 by executing a program. Examples of processors include CPUs (Central Processing Units), GPUs (Graphics Processing Units), and microprocessors.

[0104] Programs can also be recorded on computer-readable recording media. Examples of computer-readable recording media include storage devices such as hard disks, optical disks, optical discs, and semiconductor memory. Programs can also be transmitted via electrical communication lines.

[0105] Furthermore, all or part of the functions of controller 112 can also be implemented using custom LSIs (Large Scale Integrated Circuits) such as ASICs (Application Specific Integrated Circuits) and PLDs (Programmable Logic Devices). Examples of PLDs include PALs (Programmable Array Logic), GALs (Generic Array Logic), CPLDs (Complex Programmable Logic Devices), and FPGAs (Field Programmable Gate Arrays). Such integrated circuits are also included in the example of a processor.

[0106] Explanation of reference numerals in the attached figures

[0107] 1…Braking system; 101…Air tank; 102…Common control valve; 103…Air spring; 104…Variable load valve; 105…Emergency solenoid valve; 106…Relay valve; 107…Brake cylinder; 108…Brake setting device; 109…AC pressure sensor; 110…BC pressure sensor; 111…Variable load sensor; 112…Controller; 113…Relay valve sensor; 201…Signal input unit; 202…Sensor anomaly determination unit; 203…Conversion unit; 204…Brake force determination unit; 205…Feedback control unit; 206…Signal output unit; 207…Brake anomaly determination unit; 208…Status storage unit; 209…Notification unit.

Claims

1. A fluid control system, comprising: Equipment that controls the flow of fluid in a flow path; A first sensor, located at an upstream portion of the device in the flow path, is used to measure state quantities related to the fluid flowing into the device; A second sensor, located downstream of the device in the flow path, is used to measure the state quantity related to the fluid flowing out of the device; The processing unit processes data based on measurements taken from a reference sensor, which serves as one of the first and second sensors. Anomaly determination unit determines whether the reference sensor is abnormal; as well as The estimation unit, based on the characteristics of the device, calculates an estimate of the measurement value of the reference sensor according to the measurement values ​​of the sensor that is not the reference sensor among the first sensor and the second sensor. In cases where the reference sensor is determined to be malfunctioning, the processing unit uses the estimated value to perform the processing.

2. The fluid control system according to claim 1, wherein, The fluid control system is installed on the railway vehicle. The processing unit controls the brakes of the railway vehicle based on the measured value or the estimated value.

3. The fluid control system according to claim 1, wherein, The fluid is air. The state quantities measured by the first sensor and the second sensor are the air pressure or flow rate.

4. The fluid control system according to claim 1, wherein, The device in question is a valve.

5. The fluid control system according to claim 4, wherein, The device in question is a flow amplification valve.

6. A braking system installed on a railway vehicle, said braking system comprising: An air brake that operates by using air supplied from an air source through a flow path; A pilot pressure generating unit is disposed in the flow path for generating pilot pressure of the air brake by means of air supplied from the air source; A valve, which is disposed in the flow path between the pilot pressure generating section and the air brake; A first sensor, disposed in the portion between the valve and the pilot pressure generating unit in the flow path, is used to measure the state quantity of air flowing into the valve; The second sensor, which is disposed in the part between the valve and the air brake in the flow path, is used to measure the state quantity of the air flowing out of the valve; The processing unit performs feedback control of the pilot pressure generation unit based on the measurement value of a reference sensor, which is one of the first and second sensors, and the target pressure of the air brake. Anomaly determination unit determines whether the reference sensor is abnormal; as well as The estimation unit, based on the characteristics of the valve, calculates an estimate of the measurement value of the reference sensor according to the measurement values ​​of the sensor that is not the reference sensor among the first and second sensors. In cases where the reference sensor is determined to be malfunctioning, the processing unit uses the estimated value to perform the feedback control.

7. The braking system according to claim 6, wherein, If the difference between the measured value and the estimated value of the reference sensor remains below a threshold for a specified period, the anomaly determination unit determines that the anomaly of the reference sensor has disappeared. After determining that the abnormality of the reference sensor has disappeared, the processing unit performs processing based on the measurement value of the reference sensor.

8. The braking system according to claim 6, wherein, The system includes a notification unit that notifies the system of anomalies when the anomaly determination unit determines that the reference sensor is malfunctioning.

9. An anomaly detection system, comprising: The valve unit comprises a device, a first sensor, and a second sensor, wherein... The device controls the fluid flowing in the flow path. The first sensor is located in the upstream portion of the device in the flow path for measuring state quantities related to the fluid flowing into the device. The second sensor is located in the downstream portion of the device in the flow path for measuring the state quantities related to the fluid flowing out of the device. The estimation unit, based on the characteristics of the device, calculates an estimated value of the measurement value of the other sensor among the first sensor and the second sensor, according to the measurement value of one of the first sensor and the second sensor. as well as The anomaly determination unit determines whether the valve unit is abnormal based on the deviation between the measured value and the estimated value of the other sensor.

10. A braking system installed on a railway vehicle, the braking system comprising: An air brake that operates by using air supplied from an air source through a flow path; A pilot pressure generating unit is provided in the flow path to generate the pilot pressure of the air brake by means of air supplied from the air source; A valve unit includes a valve, a first sensor, and a second sensor. The valve is disposed in the flow path between the pilot pressure generating section and the air brake. The first sensor is disposed in the flow path between the valve and the pilot pressure generating section and is used to measure the pressure of air flowing into the valve. The second sensor is disposed in the flow path between the valve and the air brake and is used to measure the pressure of air flowing out of the valve. The estimation unit, based on the characteristics of the valve, calculates an estimated value of the measurement value of the other sensor from the first sensor and the second sensor, according to the measurement value of one of the first and second sensors; and The anomaly determination unit determines whether the valve unit is abnormal based on the deviation between the measured value and the estimated value of the other sensor.

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