Abnormality detection device

Abstract

To provide an abnormality detection device capable of performing highly reliable detection regardless of the characteristics of a vehicle or the influence of traveling in a configuration for detecting the detachment abnormality of a temperature sensor in a brake device.SOLUTION: The abnormality detection device executes processing for determining the sensor-separated abnormality for each temperature sensor based on the brake temperature of the brake device, and does not determine the sensor-separated abnormality when the brake temperatures are detected in the same time zone even if the respective brake temperatures are fluctuated in one brake device and the other brake device. Therefore, for example, even if the temperature fluctuation of the brake temperature occurs due to the air outside the vehicle entering the brake device due to the characteristics of the vehicle or the influence of traveling, it is possible to prevent the sensor-separated abnormality from being detected even though the temperature sensor is not separated.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an abnormality detection device. [Background technology]

[0002] Conventionally, drum brakes have been used as braking devices in relatively large vehicles such as trucks, buses, and trailers. In this type of braking device, a temperature sensor is attached to the surface of the brake shoe to measure the brake temperature, which is the temperature of the drum brake, and a technology is provided to detect abnormal temperature increases. Furthermore, if the temperature sensor comes off the brake shoe surface, it will no longer be able to measure the brake temperature correctly. For this reason, for example, Patent Document 1 employs a configuration in which the fluctuation range of the brake temperature gradient over a predetermined period is calculated, and if the fluctuation range exceeds a threshold value, it is detected as an abnormality in the mounting state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-160161 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the above configuration, if the temperature sensor becomes detached from the surface of the brake shoe, it can be detected as an abnormality in the mounting state of the temperature sensor based on the fluctuation range of the brake temperature. However, depending on the vehicle, the brake temperature may fluctuate significantly during driving. Therefore, it was necessary to determine the threshold value for the fluctuation range for each vehicle characteristic, rather than setting a unique value. For example, if the threshold for the fluctuation range of brake temperature is set to a relatively low value in a vehicle that is prone to air getting into the drum brakes, the way the vehicle is driven may allow air from outside the vehicle to get into the drum brakes, causing fluctuations in brake temperature, which may increase the fluctuation range and cause the temperature sensor to detect an abnormality in the installation even though the temperature sensor is not detached.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and its purpose is to provide an abnormality detection device that is configured to detect abnormalities such as disconnection of a temperature sensor in a brake device, and that enables highly reliable detection regardless of the characteristics of the vehicle or the influence of driving. [Means for solving the problem]

[0006] According to the abnormality detection device of claim 1, a process is executed to determine whether a sensor disconnection abnormality exists for each temperature sensor (5) based on the brake temperature as detected information, and even if there is a temperature fluctuation in the brake temperature between one brake device and another brake device, if the temperature fluctuations are detected during the same time period, the abnormality is not determined to be a sensor disconnection abnormality.

[0007] Therefore, even if the brake temperature fluctuates due to, for example, air from outside the vehicle entering the brake device as the vehicle moves, it is possible to prevent the temperature sensor from detecting a sensor disconnection abnormality even though the temperature sensor is not disconnected. Furthermore, even if the magnitude of the temperature fluctuation differs depending on the vehicle, if multiple brake temperature fluctuations are detected in the same time period on the vehicle, these can be excluded from the determination of a disconnection abnormality, making it possible to perform detection with high reliability overall. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing the configuration of a vehicle equipped with an abnormality detection device according to a first embodiment; [Figure 2] Illustration showing drum brakes [Figure 3]FIG. 1 is a perspective view showing the vicinity of a temperature sensor attached to a drum brake; [Figure 4] Electrical block diagram of the vehicle system, focusing on the abnormality detection device [Figure 5] Flowchart showing the anomaly detection process (part 1) [Figure 6] Flowchart showing the anomaly detection process (part 2) [Figure 7] Flowchart showing the anomaly detection process (part 3) [Figure 8] An explanatory diagram showing the correspondence between the waveforms of multiple brake temperatures T1 to T6 and the waveforms of the temperature gradients ΔT2, ΔT4, and ΔT6 of the right brakes 2, 4, and 6. [Figure 9] This is an explanatory diagram of the waveforms of the temperature gradients ΔT1, ΔT3, and ΔT5 of the left brakes 1, 3, and 5, when a sensor disconnection abnormality occurs in brake 3, which is the detection target. [Figure 10] A diagram equivalent to Figure 9 when the detection target is brake 1 [Figure 11] FIG. 10 is a plot diagram showing the relationship between the average value of the brake temperature and the maximum value of the temperature gradient fluctuation range in the second embodiment. [Figure 12] FIG. 10 is a plot diagram showing the relationship between the average value of the relative temperature related to the outside air temperature and the maximum value of the temperature gradient fluctuation range in the third embodiment. [Figure 13] FIG. 10 is a plot showing the relationship between the average value of the brake temperature and the maximum value of the temperature gradient fluctuation range in another vehicle according to the fourth embodiment. [Figure 14] 10 is a diagram showing a plurality of plots in which the relationship between the average value of the brake temperature and the maximum value of the temperature gradient fluctuation range is plotted for each temperature sensor in the fifth embodiment. [Figure 15] FIG. 13 is a diagram showing a plurality of plots in which the relationship between the average value of the relative temperature related to the outside air temperature and the maximum value of the temperature gradient fluctuation range is plotted for each temperature sensor in the sixth embodiment. [Figure 16] (a) and (b) are explanatory diagrams showing temperature fluctuations when the temperature sensor is normal and when it is disconnected. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, a number of embodiments embodying the present invention will be described with reference to the accompanying drawings. Note that substantially the same components in the respective embodiments will be designated by the same reference numerals, and the description thereof will be omitted.

[0010] First Embodiment In FIG. 1, an abnormality detection device 1 that constitutes a vehicle system is mounted on a relatively large vehicle, for example, a trailer 2 serving as a towed vehicle, and the trailer 2 is coupled to and towed by a tractor head 2' serving as a towing vehicle. The trailer 2 has three axles 3a-3c, for example, a front axle 3a, a middle axle 3b, and a rear axle 3c, and tires are attached to both sides of the axial direction of each axle 3a-3c. Note that Fig. 1 is a schematic bird's-eye view, and for the sake of convenience, the axles 3a-3c are shown by dashed lines. In Fig. 1, the axial direction of the axles 3a-3c is defined as the left-right direction, and the tractor head 2' side of the vehicle is defined as the front side.

[0011] A pair of left and right brake devices 10 are provided on both left and right ends of each of the axles 3a to 3c. -1 ~10 -6 In this case, a pair of left and right brake devices corresponding to the front axle 3a, the middle axle 3b, and the rear axle 3c are respectively designated by the reference numerals "10" and "11". -1 , 10 -2 "," "10 -3 , 10 -4 " and "10 -5 , 10 -6 " is expressed as

[0012] Brake device 10 of this embodiment -1 ~10 -6 2. In this embodiment, the brake device 10 -1 ~10 -6 In order to detect the respective temperatures T1 to T6 of the brakes, the temperature sensors 5 shown in FIGS. -1 ~5 -6 is used. Therefore, in the following, the brake device 10 -1 ~10 -6 and temperature sensor 5-1 ~5 -6 When referring to these collectively, they are also referred to as "brake device 10" or "temperature sensor 5." Furthermore, when referring to the brake temperatures T1 to T6 or the axles 3a to 3c, they are also referred to as "brake temperature T" or "axle 3" to simplify the explanation.

[0013] As shown in FIG. 2, the braking device 10 includes a brake drum 11, a brake shoe 12, a brake lining 13, an S-cam 14, and a return spring 15 as main components. The brake drum 11 has a cylindrical outer shell, is connected to the axle 3 and rotates together with the tire.

[0014] 2 and 3, the brake shoe 12 has an arc-shaped rim 12a and a reinforcing portion 12b standing on the inner periphery of the rim 12a, and is composed of a pair of members that form a generally crescent shape overall. The pair of brake shoes 12 are arranged on the inner periphery of the brake drum 11 so that the rims 12a of the pair of brake shoes 12 face the inner periphery of the brake drum 11 with a predetermined gap between them.

[0015] Two brake linings 13 are provided on the surface of the rim 12a of each brake shoe 12 facing the brake drum 11. The brake linings 13 are pressed against the inner peripheral surface of the brake drum 11 to generate braking force. As shown in Figures 2 and 3, the two brake linings 13 are arranged on the outer periphery of the rim 12a with a gap 13a of about 10 mm between them, so that the rim 12a can be seen through this gap 13a on the outer periphery.

[0016] As shown in Figure 2, the S cam 14 has an outer periphery that forms a roughly S-shaped abutment portion, and is rotatably arranged at a position where it abuts against the ends of the reinforcing portions 12b of the pair of brake shoes 12, respectively. When the brake pedal (not shown) is depressed, the actuator 16 shown in Fig. 2 rotates the S-cam 14 in a direction that widens the gap between the ends of the pair of brake shoes 12, that is, in a direction that presses the brake lining 13 against the brake drum 11. At this time, the frictional force generated between the brake lining 13 and the brake drum 11 is used to brake the rotation of the brake drum 11 and, ultimately, the rotation of the tire or wheel.

[0017] As shown in FIG. 2, the return spring 15 is disposed on the end side (S cam 14 side) of the reinforcing portions 12b of the pair of brake shoes 12, and is connected so as to span across each of the reinforcing portions 12b. When the brake pedal is released, the actuator 16 rotates the S cam 14 in a direction narrowing the gap between the ends of the pair of brake shoes 12. At this time, the biasing force of the return spring 15 creates a gap between the brake lining 13 and the brake drum 11, releasing the braking.

[0018] Next, the temperature sensor 5 in the above-mentioned brake device 10 and a method for installing the same will be described. The temperature sensor 5 is configured with a contact-type temperature detection element, such as a thermistor whose resistance value changes depending on the ambient temperature. The temperature sensor 5 detects the temperature of the brake device 10 to which it is attached or the surrounding area as a brake temperature T via a mounting fixture 6 shown in Figure 3.

[0019] Specifically, in Figure 3, the temperature sensor 5 is L-shaped and consists of a first rod-shaped portion 21 extending horizontally and a second rod-shaped portion 22 extending radially from the rim 12a, and each of the rod-shaped portions 21, 22 is formed from a metallic cylindrical member. The tip end of the first rod-shaped portion 21 is a temperature-sensing portion for detecting the temperature of the temperature sensor 5. The temperature sensor 5 is attached with the temperature-sensing portion along the rim 12a by the attachment fixture 6, and detects the brake temperature T, i.e., the temperature of the brake shoe 12.

[0020] The mounting fixture 6 shown in Fig. 3 integrally comprises a main body portion 23 that fits along the inner peripheral surface of the rim 12a, and a first folded portion 24 and a second folded portion 25 that are folded and formed on both longitudinal ends of the main body portion 23. The mounting fixture 6 is formed by processing a single metal plate so that the main body portion 23 and the folded portions 24, 25 form a generally S-shape as a whole (when viewed from the side).

[0021] Although detailed illustration is omitted, the mounting fixture 6 has its main body portion 23 and first folded portion 24 facing each other with the rim 12a sandwiched between them, and the distance between them 23, 24 narrows toward the tip of the first folded portion 24, so that it functions as a clip, so to speak. In this case, the distance between the main body portion 23 and the tip of the first folded portion 24 in the mounting fixture 6 is set to be narrower than the thickness of the rim 12a, and the rim 12a is sandwiched between them by the elastic force of the folded portion 24 acting between them 23, 24, so that the mounting fixture 6 together with the temperature sensor 5 is held relative to the brake shoe 12.

[0022] 3, the mounting fixture 6 has slits 26a formed by cutting out the central portions in the width direction of the main body portion 23 and the second folded portion 25. The slits 26a in the main body portion 23 allow the first rod-shaped portion 21 of the temperature sensor 5 to communicate with the rim 12a side, and the slits 26a in the second folded portion 25 allow the second rod-shaped portion 22 to pass through.

[0023] The fixture 6 is provided with a semicircularly curved slit cover 26b located on the side of the main body 23. The slit cover 26b extends along the slit 26a so as to cover the first rod-shaped portion 21 of the temperature sensor 5.

[0024] The temperature sensor 5 is attached to the brake device 10 using the above-mentioned attachment tool 6 as follows. That is, first, the tip of the first folded portion 24 of the mounting fixture 6 is positioned in the gap 13a of the brake lining 13, and the main body portion 23 is inserted so as to be aligned with the inner circumferential surface of the rim 12a. At this time, the temperature sensor 5 is placed on the inner circumferential surface side of the rim 12a so that the tip portion of the first rod-shaped portion 21 is housed within the slit cover 26b.

[0025] As a result, when the mounting fixture 6 is attached between the main body 23 and the first folded portion 24, the rim 12a is sandwiched from its edge side, and the first rod-shaped portion 21 of the temperature sensor 5 is held by the slit cover 26b, and the second rod-shaped portion 22 is held so as to fit into the slit 26a of the second folded portion 25. In this way, the temperature sensor 5 is held and attached to the rim 12a by the elastic force of the first folded portion 24 of the mounting fixture 6, with the first rod-shaped portion 21 abutting against the inner circumferential surface of the rim 12a.

[0026] The abnormality detection device 1 mounted on the trailer 2 shown in FIG. -1 ~5 -6 Based on the detection signal, each brake device 10 -1 ~10 -6 The brake temperatures T1 to T6 are acquired, and each temperature sensor 5 -1 ~5 -6 It is designed to detect any abnormalities in the wearing condition of the device as being detached.

[0027] FIG. 4 is an electrical block diagram of a vehicle system that mainly shows the abnormality detection device 1. As shown in FIG. 4 and FIG. 1, the vehicle system of this embodiment includes an abnormality detection device 1, a temperature measuring device 31, a warning device 32, and in-vehicle devices 33 connected thereto.

[0028] The temperature measuring device 31 is connected to, for example, six brake devices 10 shown by dashed lines in FIG. -1 ~10 -6 Six (individual) temperature sensors5 -1 ~5 -6 and an outside air temperature sensor 310 (shown only in FIG. 4) separately mounted on the trailer 2. Temperature Sensor 5 -1 ~5 -6 is a contact type that is attached in contact with the brake shoe 12 as described above. In contrast, the outside air temperature sensor 310 is composed of a well-known temperature sensor that measures the outside air temperature, which is the temperature around the trailer 2 (external temperature).

[0029] The warning device 32 has a display unit 32a, for example, a liquid crystal panel (see FIG. 4), and is disposed near the front end of the trailer 2 shown in FIG. 1. The warning device 32 includes a temperature sensor 5 -1 ~5 -6 If an abnormality such as a disconnection occurs, the occurrence of the abnormality is notified on the display unit 32a. Note that even when the driver is riding on the tractor head 2', the contents displayed on the display unit 32a (the occurrence of an abnormality) can be seen by the driver near the coupling with the trailer 2 through the side mirror.

[0030] The in-vehicle devices 33 are composed of a group of devices that acquire the behavior of the trailer 2 in response to the driver's driving operation or the vehicle state that indicates the state of the vehicle. Specifically, in Fig. 4, "brake signal," "vehicle speed signal," and "acceleration signal" indicated by reference numerals 331, 332, and 333 are detected by, for example, a brake sensor, a vehicle speed sensor, and an inclination sensor (not shown), and are detected as detection signals relating to the vehicle state.

[0031] The on-board devices 33 may use other sensors or devices that acquire detection signals indicating the speed, acceleration, braking state, etc. of the trailer 2, and such devices may include, for example, a GPS receiver that receives a Global Positioning System (GPS) signal. Also, for example, a configuration may be used in which detection signals of acceleration in absolute three-axis directions (the direction of gravity, east-west, and north-south) are acquired by combining a plurality of sensors including a gyro sensor in addition to the tilt sensor, or a configuration may be used in which detection signals related to starting and running states are acquired, including a detection signal indicating whether the ACC is on or off, which will be described later.

[0032] The abnormality detection device 1 includes an AD conversion unit 301, a display unit 302, a vehicle information acquisition unit 303, and a calculation unit 30 shown in FIG. The AD conversion unit 301 converts the temperature of each temperature sensor 5 -1 ~5 -6 and the outside air temperature sensor 310, and -1 ~5 -6, 310 are converted into digital data and output to the calculation unit 30. The vehicle information acquisition unit 303 acquires a brake signal, a vehicle speed signal, an acceleration signal, etc. from the above-mentioned in-vehicle devices 33 and outputs them to the calculation unit 30.

[0033] The display unit 302 is configured with, for example, a liquid crystal panel, and is disposed on the surface of a control box (not shown) that houses the abnormality detection device 1. The display unit 302 of the abnormality detection device 1, like the display unit 32a of the warning device 32, is -1 ~10 -6 It functions as a notification unit that notifies the occurrence of an abnormality related to the

[0034] The control box of the abnormality detection device 1 is located at the bottom of the side of the trailer 2 shown in FIG. 1, and is installed in a direction that allows the display unit 302 to be easily viewed. In addition, in each of the display units 302 and 32a, for example, a temperature sensor 5 -1 ~5 -6 When a disconnection abnormality occurs, which of the brake devices 10 -1 ~10 -6 The brake device 10 may be displayed so that it can be identified whether the abnormality has occurred. -1 ~10 -6 In this case, if a brake system malfunction such as brake drag occurs, the brake temperature may deviate from the normal range and rise excessively. Naturally, this is notified by the display units 302 and 32a.

[0035] The calculation unit 30 is mainly composed of a microcomputer including a CPU 30a, a memory 30b, etc., and the memory 30b is composed of a storage unit such as a ROM, a RAM, or a flash memory. The memory 30b stores various programs and preset gradient thresholds, which will be described later. The software configuration (execution of the programs) of the calculation unit 30 constitutes a control unit, which functions as a temperature acquisition unit that acquires the brake temperatures T1 to T6, a calculation unit that calculates the temperature gradients based on the brake temperatures T1 to T6, a correction unit that corrects the gradient thresholds of the temperature gradients, and a temperature sensor 5. -1 ~5 -6 The function of the abnormality detection unit is realized to detect the disconnection abnormality of each of the above.

[0036] Here, the disconnection abnormality of the temperature sensor 5 will be described with reference to FIGS. 16(b) and 16(a), which show temperature fluctuations during disconnection abnormality and normal operation. First, as shown in Figure 16(a), when the sensor is in a normal state, that is, when the temperature sensor 5 is held by the mounting fixture 6 in its original installation position (see Figure 3), the brake temperature T gradually increases over time from the start of use of the brake device 10 (use of the brakes), and exhibits a gradual temperature fluctuation.

[0037] This is because the temperature sensor 5 measures the temperature T of the brake shoe 12, which has a relatively large heat capacity, and the change in temperature T follows a gentle curve, and it can be said that the temperature change (temperature gradient) is approximately constant and does not fluctuate significantly over time.

[0038] In contrast, in the case of "abnormal sensor disconnection" shown in FIG. 16(b), the brake temperature T changes little by little as time passes after the start of brake use, coupled with vibrations of the trailer 2 and the like. This is caused by the temperature sensor 5 shifting or rattling from its original mounting position (initial mounting position on the rim 12a), or by the mounting fixture 6 shifting, falling off or being damaged from its original mounting position, causing the temperature sensor 5 to be out of contact with the brake shoe 12.

[0039] For this reason, for example, during the time period "ex2" in Figure 16(b), the temperature sensor 5 is in contact with the brake shoe 12 and measuring the brake temperature T, but during the time period "ex1", it is considered to be in a state where it is away from the brake shoe 12 and measuring the air temperature. Therefore, the temperature gradient when the sensor is disconnected is larger than when the sensor is normal (for example, see the waveform of "Brake 3" in FIG. 9, which will be described later).

[0040] Therefore, in this embodiment, the temperature gradient is calculated based on detection information (e.g., brake temperature T) related to the installation state of the temperature sensor 5, and if the temperature gradient is at least equal to or greater than a preset gradient threshold value (e.g., Th5, Th6, and Th7 in Figure 7 described later), it is determined that the temperature sensor 5 has become detached (see S22 to S29 in the same figure).

[0041] The temperature gradient ΔT is calculated as the amount of change in the brake temperature T per predetermined first unit time (for example, 1 (sec), also referred to as "unit time ta") (see S2 in FIG. 5). In addition, in this embodiment, the broad definition of "temperature gradient" includes not only the narrow definition of "temperature gradient ΔT" per unit time ta, but also the maximum and minimum values ​​of the temperature gradient ΔT within a second unit time tb that is longer than the unit time ta.

[0042] More specifically, in the graph of the temperature gradient waveform shown in the lower half of FIG. 8 (described later), "tb" on the horizontal axis represents the second unit time (e.g., 100 seconds), and corresponds to a time range going back a predetermined period from the present (hereinafter also referred to as "retroactive period tb"), as indicated by "-tc-tb" in the same figure, where the time difference from the actual measurement time to the "present" is the time lag tc (e.g., 10 seconds).

[0043] The small circles "·" shown on the temperature gradient waveform in Figure 8 indicate multiple maximum and minimum values ​​of the temperature gradient ΔT during the retrospective period tb, and the dashed circles indicate the "maximum maximum value," which is the largest of the maximum values, and the "minimum minimum value," which is the smallest of the minimum values, both of which are extracted by the calculation unit 30.

[0044] In this case, for example, it is a prerequisite for determining that there is an abnormal disconnection of the temperature sensor 5 (S29) that the maximum maximum value of the temperature gradient ΔT is greater than or equal to the gradient threshold Th5 (S22: YES in FIG. 7), and the minimum minimum value is less than or equal to the gradient threshold Th6 (S24: YES), and the difference between the maximum maximum value and the minimum minimum value is greater than or equal to the gradient threshold Th7 (S26: YES). Regarding "the minimum minimum value is less than or equal to the gradient threshold Th6", since each indicates a negative value (temperature drop), in other words (when viewed in terms of absolute value), it corresponds to "the absolute value of the minimum minimum value is greater than or equal to the absolute value of the gradient threshold Th6". Also, the difference between the maximum maximum value and the minimum minimum value is the fluctuation range of the temperature gradient obtained as an absolute value, and it is to be compared with the gradient threshold Th7 (see S26).

[0045] ... In the present embodiment, regarding the gradient threshold, in addition to the above Th5 to Th7, a plurality of types of thresholds such as Th1 to Th4 or Th8 are preset. Here, Th1 is a threshold for calculating a maximum value candidate, Th2 is a threshold for calculating a minimum value candidate, Th3 is a threshold for calculating a maximum value, Th4 is a threshold for calculating a minimum value, and further, the above Th5 is a threshold for calculating a maximum maximum value, Th6 is a threshold for calculating a minimum minimum value, and Th7 is a threshold for the difference (for counting up). Furthermore, Th8 is a confirmation counter threshold for determining an abnormal disconnection of the sensor. These thresholds are set, for example, such that Th1 < Th3 = Th5 < Th7, and in terms of the absolute values of Th2, Th4, and Th6, Th2 < Th4 = Th6 < Th7. Also, Th8 is set to a value of 2 or more, and Th1 to Th8 can be set to appropriate values respectively, which will be described in detail in the flowcharts after FIG. 5.

[0046] And the arithmetic unit 30 of the present embodiment executes a process of determining such an abnormal disconnection for each of the temperature sensors 5 -1 ... ~5 -6 and, for each of the plurality of brake devices 10 -1 ... ~10 -6If temperature fluctuations in the brake temperatures T of one of the brake devices and the other brake devices are detected during the same time period, they are excluded from the judgment of a disconnection abnormality as they are affected by the traveling of the trailer 2.

[0047] 5 to 7 show the flow of processing executed by the calculation unit 30 of the abnormality detection device 1, but for simplicity of explanation, the abnormality detection device 1 will be mainly described. In addition, S1, S2, ... in the figures represent steps, and the abnormality detection device 1 may, for example, detect one brake device 10 as a detection target. -2 Even during the execution of the process of the brake device 10 (denoted as "Brake 2" in FIG. 8), -4 ,10 -6 (hereinafter referred to as "Brake 2" and "Brake 6") are executed in parallel. The above processes are executed repeatedly at predetermined intervals during operation in the abnormality detection device 1.

[0048] Furthermore, in FIG. 8, the brake device 10 -1 ~10 -6 The upper half of the figure shows the waveforms of the brake temperatures T1 to T6 and the vehicle speed V of the trailer 2, with the brake temperatures T1 to T6 being designated as "Brake 1" to "Brake 6". -2 ,10 -4 ,10 -6 The graph shows the waveforms of the temperature gradients ΔT2, ΔT4, and ΔT6 calculated based on the respective brake temperatures T2, T4, and T6.

[0049] As shown in FIG. 5, the abnormality detection device 1 detects one brake device 10 -2 The brake temperature T2 is acquired (S1), and the temperature gradient ΔT2 per unit time ta is calculated (S2).

[0050] Next, the abnormality detection device 1 determines whether the maximum value candidate or the minimum value candidate has not yet been saved in the buffer b1 (S3). The buffer b1 is a buffer (a storage area of ​​the memory 30b) for temporarily storing the temperature gradient ΔT2 that is the maximum value candidate or the minimum value candidate together with the time at which it was actually measured (also simply referred to as "time"). In addition to the storage area, the memory 30b is provided with a storage area for previously setting and storing each of the threshold values ​​Th1 to Th8.

[0051] If the abnormality detection device 1 determines that the maximum value candidate or minimum value candidate is stored in the buffer b1 and is not unsaved (S3: NO), it proceeds to S10 in Figure 6 (the processing proceeds to "A" in Figure 6). On the other hand, if the abnormality detection device 1 determines in S3 that the maximum value candidate or the minimum value candidate has not been stored in the buffer b1 (S3: YES), it determines whether the temperature gradient ΔT2 calculated in S2 is greater than or equal to the gradient threshold Th1 for calculating the maximum value candidate (S4).

[0052] If the abnormality detection device 1 determines that the temperature gradient ΔT2 is greater than or equal to the gradient threshold Th1 (℃ / s) (S4: YES), it stores the temperature gradient ΔT2 and the time in buffer b1 as a candidate maximum value (S5), and then proceeds to "C" in Figure 7 and returns. On the other hand, if the abnormality detection device 1 determines that the temperature gradient ΔT2 is less than the gradient threshold Th1 (S4: NO), it determines whether the temperature gradient ΔT2 is equal to or less than the gradient threshold Th2 for calculating the minimum value candidate (S6).

[0053] If the abnormality detection device 1 determines that the temperature gradient ΔT2 is greater than the gradient threshold Th2 (°C / s) (S6: NO), it proceeds to "C" in Figure 7 and returns without saving the temperature gradient ΔT2 or the time. In contrast, if the abnormality detection device 1 determines that the temperature gradient ΔT2 is less than or equal to the gradient threshold Th2 (S6: YES), it stores the temperature gradient ΔT2 and the time in buffer b1 as a minimum value candidate (S7), and then proceeds to "C" in Figure 7 and returns.

[0054] Thus, if a maximum value candidate or a minimum value candidate is stored in buffer b1 (S3: NO), the abnormality detection device 1 proceeds to S10 in Figure 6 and determines whether the temperature gradient ΔT2 most recently stored in buffer b1 is a maximum value candidate. If the most recently saved temperature gradient ΔT2 is not a minimum value candidate but a maximum value candidate (S10: YES), the abnormality detection device 1 subtracts the value of the maximum value candidate from the temperature gradient ΔT2 newly (currently) calculated in S2, and determines whether the difference is less than or equal to the threshold value Th3 for calculating the maximum value (S11).

[0055] If the difference obtained by the subtraction is equal to or less than the threshold value Th3 (°C / s) (S11: YES), the abnormality detection device 1 stores the value of the maximum value candidate most recently stored in buffer b1 as the maximum value in buffer b2 (S12), while storing and updating the temperature gradient ΔT and time calculated this time as the minimum value candidate in buffer b1 (S13), and proceeds to S21 in Figure 7 (proceeds to "B"). The buffer b2 is a storage area of ​​the memory 30b for temporarily storing the temperature gradient ΔT2 at which the maximum or minimum value is reached. In Fig. 8, the maximum or minimum value is indicated by a small circle "·" on the waveform of the temperature gradient ΔT2 of "Brake 2."

[0056] In contrast, if the abnormality detection device 1 determines that the difference subtracted in S11 is greater than the threshold value Th3 (S11: NO), it determines whether the temperature gradient ΔT2 calculated this time is greater than or equal to the value of the maximum value candidate for buffer b1 (S14). If the abnormality detection device 1 determines that the temperature gradient ΔT2 calculated this time is equal to or greater than the value of the maximum value candidate in buffer b1 (S14: YES), it saves and updates the temperature gradient ΔT2 and time in buffer b1 as the maximum value candidate (S15), and proceeds to S21 in Figure 7. If the currently calculated temperature gradient ΔT2 is less than the maximum value candidate value of buffer b1 (S14: NO), the process proceeds to S21 in FIG. 7 without updating the contents stored in buffer b1.

[0057] In S10 of Figure 6, if the temperature gradient ΔT2 most recently stored in buffer b1 is determined to be a minimum value candidate (S10: NO), the abnormality detection device 1 subtracts the temperature gradient ΔT2 of the minimum value candidate from the temperature gradient ΔT2 calculated this time, and determines whether the difference is greater than or equal to the threshold value Th4 for calculating the minimum value (S16).

[0058] If the difference obtained by the subtraction is equal to or greater than the threshold value Th4 (°C / s) (S16: YES), the abnormality detection device 1 stores the value of the minimum value candidate most recently stored in buffer b1 as the minimum value in buffer b2 (S17), while storing and updating the temperature gradient ΔT and time calculated this time in buffer b1 as the maximum value candidate (S18), and proceeds to S21 in Figure 7 (proceeds to "B").

[0059] On the other hand, if the abnormality detection device 1 determines that the difference subtracted in S16 is less than the threshold value Th4 (S16: NO), it determines whether the temperature gradient ΔT2 calculated this time is less than or equal to the value of the minimum value candidate of buffer b1 (S19). If the abnormality detection device 1 determines that the temperature gradient ΔT2 calculated this time is equal to or less than the value of the minimum value candidate in buffer b1 (S19: YES), it saves and updates the temperature gradient ΔT2 and time in buffer b1 as the minimum value candidate (S15), and proceeds to S21 in Figure 7. If the currently calculated temperature gradient ΔT2 is greater than the value of the minimum value candidate in buffer b1 (S19: NO), the process proceeds to S21 in FIG. 7 without updating the contents stored in buffer b1.

[0060] In S21 of FIG. 7, the abnormality detection device 1 determines whether or not a period equal to a multiple of the unit time tb (for example, 100 (sec)) has elapsed. That is, the abnormality detection device 1 repeatedly executes S1 to S7 in FIG. 5 and S10 to S15 or S10 to 20 in FIG. 6 described above until the unit time tb has elapsed (S21: NO, "return"), and executes the following S22 each time the unit time tb has elapsed (S21: YES).

[0061] In Figure 8, "-tc-tb*5", "-tc-tb*4", "-tc-tb*3", "-tc-tb*2", "-tc-tb", and "-tc" are each retrospective periods marked with "-" and can be expressed as a multiple of the unit time "tb". In addition, a time lag "-tc" based on the "present" is taken into account in order to obtain the data. Furthermore, the "retroactive period" described in S22 onwards is expressed as "past -tc-tb~-tc", but since it corresponds to the unit time tb going back tc minutes from the present, it will be referred to as the "retroactive period tb" for convenience.

[0062] The abnormality detection device 1 determines whether or not at least one of the maximum values ​​of the temperature gradient ΔT2 stored in the buffer b2 during the retrospective period tb is equal to or greater than the gradient threshold value Th5 for calculating the maximum maximum value (S22). If even one such maximum value is equal to or greater than the gradient threshold value Th5 (°C / s) (S22: YES), the abnormality detection device 1 determines whether or not the temperature sensor 5 on the same side has detected any maximum value within td before or after the actual measurement time of the maximum maximum value in the temperature gradient ΔT2 stored in the buffer b2 during the retrospective period tb. -4 , 5 -6 It is determined whether there is any maximum value in the temperature gradients ΔT4 and ΔT6 (S23).

[0063] That is, not only "Brake 2" as a detection target shown in FIG. 8, but also other brake devices 10 -4 ,10 -6 The temperature fluctuations (temperature gradients ΔT4, ΔT6) of the brake temperatures T4, T6 of "Brakes 2, 6" on the same left-right side as the brake 2 are detected.

[0064] As a result, when the maximum value of the temperature gradient ΔT2 of brake 2, indicated by the dashed circle in Figure 8, is actually measured, if there are no maximum values ​​of the temperature gradients ΔT4 and ΔT6 of brakes 2 and 6 within td (for example, 2 (sec)) before and after the actual measurement point at approximately the same time (S23: YES), the process proceeds to S24. In FIG. 8, the actual measurement time point of the maximum maximal value of the temperature gradient ΔT2 is indicated by a vertical line (dashed line), and the same time period is defined as 2 seconds before and after this time point. However, in this embodiment, the "same time period" can be appropriately set to a value of td that can be regarded as the same time period (with a predetermined range), such as 1 second before or 3 seconds before or after the actual measurement time point.

[0065] Furthermore, the abnormality detection device 1 determines whether or not at least one of the minimum values ​​of the temperature gradient ΔT2 stored in the buffer b2 during the retrospective period tb is equal to or smaller than the gradient threshold value Th6 for calculating the smallest minimum value (S24). If even one of the minimum values ​​is equal to or less than the gradient threshold value Th6 (°C / s) (S24: YES), the abnormality detection device 1 determines whether or not the temperature sensor 5 on the same side has detected a minimum value within td before and after the actual measurement point of the smallest minimum value in the temperature gradient ΔT2 stored in the buffer b2 during the retrospective period tb. -4 , 5 -6 It is determined whether there is any minimum value in the temperature gradients ΔT4 and ΔT6 (S25).

[0066] Therefore, when the minimum maximum value of the temperature gradient ΔT2 of brake 2, indicated by the dashed circle in Figure 8, is actually measured, if there is no minimum value of the temperature gradients ΔT4, ΔT6 of brakes 2, 6 at approximately the same time within td (for example, 2 (sec)) before and after the actual measurement point (S25: YES), the process proceeds to S26.

[0067] Then, the abnormality detection device 1 subtracts the minimum minimum value from the maximum maximum value of the temperature gradient ΔT2 during the retrospective period tb, and determines whether the difference is equal to or greater than a count-up threshold Th7 (threshold Th7 related to the temperature gradient) (S26). If the subtracted difference is equal to or greater than the count-up threshold Th7 (℃ / s) (S26: YES), the abnormality detection device 1 increments the counter by 1 (S27) and then determines whether the counter is equal to or greater than the determination counter threshold Th8 (S28).

[0068] In this way, when the counter is equal to or greater than the determination counter threshold value Th8 (for example, a value of 2 or greater, such as 3 to 7) (S28: YES), the abnormality detection device 1 determines whether the brake device 10 -2Temperature sensor in 5 -2 This is notified by the display unit 32a of the warning device 32, and the process ends (returns).

[0069] As described above, one brake device 10 -2 Regarding the temperature fluctuation of the brake temperature T2 in the case where the maximum local maximum value, the minimum local minimum value (absolute value), and the fluctuation range indicating the difference between them (maximum local maximum value - minimum local minimum value) of the temperature gradient ΔT2 are equal to or greater than the respective threshold values ​​Th5, Th6 (absolute value), and Th7 (S22: YES, S24: YES, and S26: YES), and further, during the same time period when the maximum local maximum value or the minimum local minimum value of the temperature gradient ΔT2 was recorded, another brake device 10 -4 ,10 -6 When the temperature sensor 5 does not detect the maximum or minimum value of the temperature gradients ΔT4 and ΔT6 at the temperature sensor 5 (S23: YES, S25: YES), and further, the count value of the counter that counts the event reaches the counter threshold value Th8 for determination (S28: YES), -2 An abnormality in the disconnection is detected (S29).

[0070] However, if the determination is NO in any of the steps S22 to S26 (S22 to S26: NO), the count value of the counter is reset to zero (S26). Therefore, one braking device 10 -2 and other braking devices10 -4 ,10 -6 If the temperature fluctuations of the brake temperatures T2, T4, and T6 (maximum or minimum values ​​of the temperature gradients ΔT2, ΔT4, and ΔT6) are detected in the same time period (S23: NO or S25: NO), the temperature sensor 5 -2 This will exclude it from the target for determining whether there is a misalignment or abnormality.

[0071] Looking at the example of FIG. 8, the maximum and minimum values ​​of the temperature gradient ΔT2 in "Brake 2" are recorded at each unit time tb (see the dotted circle). On the other hand, the maximum and minimum values ​​of the temperature gradient ΔT4,6 for "Brakes 4,6" are also recorded (see the small circle "·"), and among these, those detected during the same time period as the maximum and minimum values ​​of the temperature gradient ΔT2 are indicated by solid circles.

[0072] As shown in the figure, the maximum and minimum values ​​of the temperature gradients ΔT4 and ΔT6 in "Brakes 4 and 6" tend to be detected at approximately the same time as the maximum and minimum values ​​of the temperature gradient ΔT2 in "Brake 2" are actually measured (see the vertical line intersecting the dashed circle). This is because, depending on the way the vehicle is driven, air outside the vehicle may enter the brake device 10, and the brake device 10 on the same side may be damaged. -2 ,10 -4 ,10 -6 This causes temperature fluctuations in the brake temperatures T2, T4, and T6, and the fluctuation range becomes larger. -2 ,5 -4 ,5 -6 This can cause the sensor to be detected as disconnected even though it is not disconnected.

[0073] Even in such a case, the above-described processes of FIGS. 5 to 7 are executed, so that the brake device 10 to be detected -2 and other braking devices10 -4 ,10 -6 When the temperature fluctuations of the brake temperatures ΔT2, ΔT4, and ΔT6 at the temperature sensors 5 and 6 are detected as the maximum or minimum values ​​in the same time period, the temperature fluctuations are excluded from the determination of sensor disconnection abnormality due to the influence of the vehicle running (S23: NO or S25: NO). -2 ,5 -4 ,5 -6 This makes it possible to prevent the sensor from being detected as being disconnected even when the sensor is not disconnected.

[0074] In contrast, in Figure 9 or Figure 10, only "Brake 3" has the temperature sensor 5 -31 shows the temperature gradient waveform when "Brake 3" or "Brake 1" is the detection target in a case where "Brake 3" or "Brake 1" is removed from its original mounting position to allow a non-contact state with the brake shoe 12 to occur.

[0075] 9, the brake device 10 to be detected in the trailer 2 is -3 and the left brake device 10, which is in the same left-right direction as this. -1 ,10 -5 The waveforms of the temperature gradients ΔT1, ΔT3, and ΔT6 are shown. The brake device 10 -3 About the temperature sensor 5 -3 When the process for determining whether or not the brake is out of alignment is started, the temperature gradient ΔT3 is calculated based on the acquired brake temperature T3 (S1, S2 in FIG. 5).

[0076] Furthermore, as described above, the process of saving and updating the maximum value candidate or maximum value and the minimum value candidate or minimum value of the temperature gradient ΔT3 in buffer b1 or b2 (the process of S3 to S7 in FIG. 5 and the process of S10 to S20 in FIG. 6) is repeatedly executed, and every time unit time tb elapses (S21: YES in FIG. 7), the maximum maximum value or minimum minimum value or its fluctuation range of the temperature gradient ΔT3 is obtained, and the process of determining whether or not it is a maximum value or minimum minimum value is compared with the threshold values ​​Th5, Th6, and Th7 associated with the respective temperature gradients (S22, S24, S26) is executed.

[0077] In this case, for "Brake 3" shown in Figure 9, the maximum and minimum values ​​of the temperature gradient ΔT3 are recorded at each unit time tb (see the dashed circles), but these measured time periods do not include the measured times of the maximum and minimum values ​​of the temperature gradients ΔT1 and ΔT5 for "Brakes 1, 5" (S23: YES and S25: YES).

[0078] This is the temperature sensor 5 that is not actually disconnected. -1 ,5 -5 Temperature sensor 5 is also disconnected -3 The latter temperature sensor 5 is also affected by driving. -3In this case, the temperature changes irregularly depending on the vehicle behavior, so the time periods of the maximum and minimum values ​​that indicate the temperature fluctuation (temperature gradient ΔT3) and the temperature sensor 5 on the left side are the same. -1 ,5 -5 It can be understood that the mismatch between the time periods of maximum and minimum values ​​showing the temperature fluctuations (temperature gradients ΔT1, ΔT5) of and occurs over multiple unit times tb. Therefore, if temperature fluctuations in the brake temperatures T2, T4, and T6 of one "Brake 3" and the other "Brakes 1, 5" are detected at different time periods (YES in all of S22 to S26), the sensor disconnection abnormality can be suitably detected without being excluded from the judgment target for sensor disconnection abnormality (S29).

[0079] In contrast, FIG. 10 differs from FIG. 9 in that the detection target is "Brake 1." For this reason, the brake device 10 -1 For this, the temperature gradient ΔT1 is calculated based on the acquired brake temperature T1 (S1, S2 in FIG. 5), and the maximum and minimum values ​​are determined (S3 to S7 in FIG. 5, S10 to S20 in FIG. 6, S21, S22, S24, S26 in FIG. 7).

[0080] In this case, in "Brake 1" shown in FIG. 10, the maximum and minimum values ​​of the temperature gradient ΔT1 are recorded at each unit time tb (see the dotted circle). During these measured time periods, the maximum and minimum values ​​of the temperature gradient ΔT5 in another "Brake 5" also tend to be detected (S23: NO or S25: NO). Therefore, the temperature sensor 5 -1 This will exclude it from the target for determining whether there is a misalignment or abnormality.

[0081] In Figures 8, 9, and 10, the processing contents (determination processing) of Figures 5 to 7 by the abnormality detection unit are explained with the detection objects being "brakes 2, 3, and 1," but it goes without saying that the same determination processing can also be performed for the other "brakes 4 to 6" with those as the detection objects.

[0082] As described above, the calculation unit 30 as the abnormality detection unit of this embodiment detects the temperature sensor 5-1 ~5 -6 Based on the detection information relating to the installation state (for example, brake temperatures T1 to T6 in FIG. 8), the temperature sensor 5 detects the detachment abnormality. -1 ~5 -6 and a process of determining whether or not a plurality of brake devices 10 -1 ~10 -6 If temperature fluctuations in the brake temperatures of one brake device (e.g., brake 2 in FIG. 8) and the other brake devices (e.g., brakes 4 and 6) are detected during the same time period, the device is excluded from the judgment of sensor disconnection abnormality as it is affected by the vehicle's running (see, for example, S23: NO or S25: NO in FIG. 7).

[0083] According to this, for example, the brake device 10 -1 ~10 -6 Based on the brake temperatures T1 to T6, the sensor disconnection abnormality is detected by the temperature sensor 5. -1 ~5 -6 A process of determining the temperature difference between each of the brake devices is executed, and even if there is a temperature difference between the brake temperatures of one brake device and another brake device, if the temperature differences are detected in the same time period, it is not determined that the sensor is disconnected. Therefore, even if the brake temperature fluctuates due to the influence of the vehicle traveling, for example, when air from outside the vehicle enters the brake device, the temperature sensor 5 -1 ~5 -6 In addition, even if the magnitude of the temperature fluctuation differs depending on the vehicle, if multiple temperature fluctuations in the brake temperature are detected in the same time period, these can be excluded from the determination of a sensor disconnection abnormality, making it possible to achieve detection with high reliability overall.

[0084] The other brake devices are at least one or more brake devices (for example, brakes 4 and 6 in FIG. 9) on the same left-right side as one brake device (for example, brake 2 in FIG. 9). In this regard, when the vehicle is traveling on a curve, the right brake device 10 -2 ,10 -4 ,10 -6Or the left brake device 10 -1 ,10 -3 ,10 -5 Therefore, the temperature gradient fluctuation range becomes larger on the same side. -2 and other braking devices10 -4 ,10 -6 By performing the above determination process assuming that the left and right directions are on the same side, it becomes possible to more appropriately detect temperature fluctuations in the brake temperatures T2, T4, and T6, which should be excluded from the determination of sensor disconnection abnormalities.

[0085] The other brake device may be the same as the first brake device on the same axle 3. For example, in FIG. 8, "Brake 2" may be the same as the first brake device 10. -2 The "Brake 1" of the same front axle 3a is set to another brake device 10 -1 Even in this case, the same effects as those of the above embodiment can be achieved.

[0086] That is, for example, in the graph of the waveforms of brake temperatures T1 to T6 shown in the upper half of Figure 8, during the time period marked with the symbol "td'" (the area surrounded by a long, thin oval), the temperatures T1 and T2 of the front "Brakes 1 and 2" both show similar temperature fluctuations that form a convex shape. This is thought to be because "Brakes 1 and 2" are located on the same front axle 3a (or the vehicle is relatively long from front to rear, such as trailer 2), combined with the effects of driving as described above, causes the range of fluctuation in the temperature gradient in "Brakes 1 and 2" to become large at the same time period td'.

[0087] Therefore, for example, for one of the detection targets, "Brake 2," the temperature gradient ΔT2 is calculated based on the acquired brake temperature T2 (S1, S2 in FIG. 5), and the maximum and minimum values ​​are determined (S3 to S7 in FIG. 5, S10 to S20 in FIG. 6, S21, S22, S24, S26 in FIG. 7).

[0088] In this case, the waveforms of the brake temperatures T1 and T2 in the upper half of FIG. 8 tend to show similar temperature fluctuations in the same time period td'. Therefore, the maximum and minimum values ​​of the temperature gradient ΔT2 of "Brake 2" in the lower half of the same figure and the maximum and minimum values ​​of the temperature gradient ΔT1 of "Brake 1" are detected in the same time period td' (S23: NO or S25: NO), and the temperature sensor 5 -2 This can be excluded from the determination of misalignment abnormalities.

[0089] The waveforms of brake temperatures T1 to T6 and temperature gradients ΔT1 to ΔT6 in Figure 8 show those when "Brakes 1 to 6" themselves are normal. Also, even when the brake temperature rises excessively due to brake drag or the like, although the degree of temperature rise differs compared to when there is no brake drag, basically the same characteristic temperature changes appear, so as described above, it is possible to detect the occurrence of an abnormality such as a sensor coming loose from the temperature gradient.

[0090] <Other embodiments> 11 to 14 show the second and subsequent embodiments of the present invention. Below, we will describe the points that are substantially different from the previously described embodiments.

[0091] In the brake device 10, the higher the brake temperature T, the larger the fluctuation range of the temperature gradient ΔT tends to be, and if the judgment threshold for sensor disconnection abnormality (for example, the gradient thresholds Th5 to Th7) is set to a relatively low value, it may exceed that value. Therefore, the abnormality detection device 1 of the second embodiment is configured to correct the gradient threshold values ​​Th5 to Th7 related to the temperature gradient ΔT in accordance with the level of the brake temperature T in the brake device 10.

[0092] Here, Figure 11 shows a plot diagram plotting the relationship between the maximum value of the fluctuation range of the temperature gradient ΔT1 to ΔT6 calculated based on the brake temperatures T1 to T6 acquired by the abnormality detection device 1 and the average value of the brake temperatures T1 to T6 when calculating this. That is, the plot in the same figure is a plot obtained by taking the average value of the brake temperatures T1 to T6 at the time of calculating the temperature gradient (for example, for the last 7 minutes) on the x-axis and the maximum value of the fluctuation range of the temperature gradients ΔT1 to ΔT6 (for example, the maximum maximum value) on the y-axis.

[0093] In FIG. 11, "vehicle α" refers to the trailer 2, and "all temperature sensors" refers to all temperature sensors 5 in the vehicle. -1 ~5 -6 The abnormality detection device 1 detects all the temperature sensors 5 of the vehicle. -1 ~5 -6 A regression analysis is performed to obtain the relationship between the average values ​​of the brake temperatures T1 to T6 and the maximum values ​​of the temperature gradients ΔT1 to ΔT6, and a regression equation is obtained from the results of the regression analysis. In this way, the correlation equation obtained by plotting in the abnormality detection device 1, that is, the approximation equation of the approximated line can be calculated using regression analysis (see the dashed line in FIG. 11).

[0094] Then, when executing the above-mentioned determination process, the abnormality detection device 1 determines the corrected slope threshold value based on the regression analysis result. For example, the corrected slope threshold value Th5' shown in Figure 11 is calculated by substituting the "average value of brake temperatures T1 to T6 over a recent fixed period (e.g., several minutes)" into the approximation formula and adding the slope threshold value Th5 (°C / s) to this value.

[0095] Similarly, for the slope thresholds Th1 to Th4, Th6, and Th7 other than the slope threshold Th5, corrected slope thresholds Th1' to Th4', Th6', and Th7' can be calculated. The above regression equation applies to all temperature sensors5 -1 ~5 -6 However, as will be described later, -1 ~5 -6 A regression equation may be created for each.

[0096] As explained in Figures 5 to 8, the abnormality detection device 1 is configured to execute a process to determine that a sensor disconnection abnormality has occurred when, for example, the maximum maximum value of the temperature gradient ΔT2 for only one "brake 2" out of "brakes 2, 4, 6" in Figure 8 is equal to or greater than the preset gradient thresholds Th5, Th6, Th7 (see S22 to S29 above), and executes a process to correct the gradient thresholds Th5, Th6, Th7 related to the temperature gradient ΔT2 to Th5', Th6', Th7', respectively, depending on the average value of the brake temperatures T including that brake temperature T2.

[0097] This correction process is performed before S22, S24, and S26 in FIG. 7 are performed, for example, when S21 is performed. Furthermore, Figure 8 shows an example in which "Brake 2" is excluded from the determination of a disconnection abnormality because the temperature fluctuations of the brake temperatures T2, T4, and T6 of one "Brake 2" and the other "Brakes 4 and 6" are detected during the same time period (S23: NO or S25: NO), as described above. However, by using the corrected slope thresholds Th5', Th6', and Th7', the slope thresholds Th5, Th6, and Th7 are set to larger values ​​as the average value of the brake temperatures T1 to T6 increases, thereby preventing the temperature sensor 5 from being detected as a disconnection abnormality even when it has not disconnected due to the temperature rise (i.e., mitigating the impact on the determinations of S22, S24, and S26).

[0098] As described above, the calculation unit 30 of the second embodiment corrects the gradient thresholds (for example, Th5, Th6, and Th7 in FIG. 7) of the temperature gradient ΔT in accordance with the level of the brake temperature T in the brake device 10. According to this, even if the fluctuation range of the temperature gradient ΔT tends to increase as the brake temperature T increases, for example, when the temperature gradient ΔT of a brake device is determined by comparing it with the gradient thresholds Th5, Th6, and Th7, the gradient thresholds Th5, Th6, and Th7 are corrected according to the level of the brake temperature T, thereby mitigating the effect of the brake temperature T and preventing the temperature sensor 5 from detecting a sensor disconnection abnormality even when it is not disconnected.

[0099] FIG. 12 shows a plot diagram of the third embodiment. The plot diagram of the third embodiment differs from that of the second embodiment in that the x-axis represents the average value of the relative temperature, which is the difference between the brake temperature T and the outside air temperature when the temperature gradient ΔT is calculated (for example, during the period immediately preceding the calculation).

[0100] That is, the abnormality detection device 1 detects all the temperature sensors 5 -1 ~5 -6 For these, the average value of the relative temperature representing the difference between these brake temperatures T1 to T6 and the outside air temperature acquired by the outside air temperature sensor 310 is calculated, and a regression analysis is performed to determine the relationship between this average value and the maximum value of the temperature gradient ΔT, and a regression equation is obtained from the results of this regression analysis. In this way, an approximation formula for an approximation line can be calculated using regression analysis, and an approximation line similar to the dashed approximation line in FIG. 11 can be obtained in FIG.

[0101] Then, when executing the above-mentioned determination process, the abnormality detection device 1 determines the corrected slope threshold value based on the regression analysis result. For example, the corrected slope threshold value Th5' is calculated by substituting the "average value of the relative temperature (brake temperature T-outside air temperature) for the period immediately surrounding the vehicle" into the approximation formula and adding the slope threshold value Th5 to this.

[0102] Similarly, for the slope thresholds Th1 to Th4, Th6, and Th7 other than the slope threshold Th5, corrected slope thresholds Th1' to Th4', Th6', and Th7' can be calculated. Then, in the judgment process of Figures 5 to 7, when the abnormality detection device 1 judges, for example, the temperature gradient ΔT of "Brake 2" in Figure 8 by comparing it with gradient thresholds Th5, Th6, and Th7 (S22, S24, S26), it corrects the gradient thresholds Th5, Th6, and Th7 to Th5', Th6', and Th7', respectively, depending on the magnitude of the relative temperature.

[0103] For the sake of convenience, the same symbols "Th5', Th6', Th7'" are used for the corrected slope thresholds in the third embodiment and the second embodiment. However, it can be said that the relative temperature obtained by subtracting the outside air temperature from the brake temperature T has a higher correlation with the fluctuation range of the temperature slope ΔT (the coefficient of determination "R 2 "reference).

[0104] As described above, the calculation unit 30 of the third embodiment corrects the gradient threshold value (for example, Th5, Th6, and Th7 in Figure 7) of the temperature gradient ΔT depending on the magnitude of the relative temperature, which is the difference between the brake temperature T in the brake device 10 and the outside air temperature. According to this, for example, even if the brake temperature T2 is the same in summer and winter, the temperature difference with the outside air is different. However, when determining the temperature gradient ΔT of a certain brake device by comparing it with the gradient thresholds Th5, Th6, and Th7, the gradient thresholds Th5, Th6, and Th7 are corrected according to the height of the relative temperature, thereby mitigating the effect of the outside air temperature on the temperature fluctuations of the brake device, and preventing the temperature sensor 5 from detecting a sensor disconnection abnormality even when it is not disconnected.

[0105] FIG. 13 shows a plot diagram of the fourth embodiment, which corresponds to FIG. 11, of a "vehicle β" different from the above vehicle (vehicle α in FIG. 11). In other words, a vehicle α such as trailer 2 and another vehicle β have different shapes and structures, and the driving styles of each vehicle α and β are also different, so the correlation between the brake temperature T and the fluctuation range of the temperature gradient ΔT is different.

[0106] Therefore, in the fourth embodiment, for each trip (from ACC on to ACC off) for the same vehicle β, the brake temperature T and the fluctuation range of its temperature gradient ΔT during that period are stored, and when the ACC is turned on again, a corrected threshold value is calculated based on the accumulated brake temperature T and the fluctuation range of the temperature gradient ΔT for a predetermined number of trips up to that point (past).

[0107] In this case, the plot in FIG. 13 shows a plot obtained by taking the average value of the brake temperature T for a predetermined number of trips in the past period on the x-axis and the maximum value of the temperature gradient ΔT on the y-axis. The abnormality detection device 1 in the vehicle β has all the temperature sensors (for example, the same temperature sensors 5 as those in the vehicle α). -1 ~5 -6 ), a regression analysis is performed to determine the relationship between the average value of the brake temperatures T1 to T6 accumulated during the past period (referred to as the "driving period" in FIG. 13) and the maximum value of the temperature gradients ΔT1 to ΔT6, and a regression equation is obtained from the results of the regression analysis.

[0108] In this way, an approximation formula for an approximate straight line can be calculated using regression analysis (see the dashed line in FIG. 13). Therefore, the corrected slope threshold value can be obtained by substituting the "average value of the brake temperature T during the past driving period" into the approximation formula and adding a preset slope threshold value to this.

[0109] In the vehicle β, for example, when the ACC is turned on, that is, before the determination process of FIGS. 5 to 7 is executed, the corrected threshold value is calculated based on the regression analysis result, and then the determination process is executed. The corrected inclination threshold value for the vehicle β can be calculated for each of the inclination threshold values ​​Th1 to Th7, similarly to the above embodiment.

[0110] As described above, the calculation unit 30 of the fourth embodiment stores the fluctuation range of the temperature gradients ΔT1 to ΔT6 calculated from the brake temperatures T1 to T6 measured for each trip on the same vehicle β, and corrects the gradient threshold for each trip based on the past brake temperatures T1 to T6 and the fluctuation range of the temperature gradients ΔT1 to ΔT6 (regression analysis results). According to this, even if the magnitude of fluctuation in brake temperature T tends to differ for each vehicle α, β, the slope threshold value (e.g., Th5, Th6, Th7) used for comparison with the temperature slope ΔT of one brake device can be corrected to a value corresponding to the temperature fluctuation of the vehicle β, thereby mitigating the effects of differences between vehicles α, β and preventing the temperature sensor 5 from being detected as having become disconnected even when it is not.

[0111] FIG. 14 shows a plot diagram of the fifth embodiment, which differs from the plot diagram of FIG. 13 described above in the following points. 14(a)(b)... are temperature sensors 5 in vehicle α. -1 ~5 -6 The plot when creating a regression equation for each temperature sensor is -1 , 5 -2 , ... are shown separately.

[0112] The abnormality detection device 1 measures the brake temperature T and the fluctuation range of the temperature gradient ΔT during each trip of the vehicle α using the temperature sensor 5. -1 ~5 -6 Each time the ACC is turned on, the temperature sensor 5 is read based on the accumulated brake temperature T and the fluctuation range of the temperature gradient ΔT for the specified number of trips up to that point. -1 ~5 -6 A corrected threshold value is calculated for each pixel.

[0113] Therefore, in the plots of Figures 14(a)(b)..., the average value of the brake temperature T for a predetermined number of trips in the past period is taken on the x-axis, and the maximum value of the temperature gradient ΔT is taken on the y-axis. -1 , 5 -2 , ... are expressed separately. The abnormality detection device 1 also includes a temperature sensor 5 -1 ~5 -6 For each of the temperature sensors 5, a regression analysis is performed to determine the relationship between the average value of the brake temperature T during the accumulated past period (denoted as "driving period" in FIG. 14) and the maximum value of the temperature gradient ΔT. From the results of the regression analysis, a regression equation is created. -1 ~5-6 Obtained every time.

[0114] In this case, the temperature sensor 5 -1 , 5 -2 The regression equations for (a), (b), and so on are given by the approximate equations of the approximate straight lines shown by the dashed lines in FIG. Therefore, the corrected slope threshold values ​​Th5', Th5', ... shown in Figs. 14(a) and 14(b) are obtained by using the temperature sensor 5 -1 , 5 -2 , ..., the "average value of the brake temperature T in the past driving period" is substituted for each, and the slope threshold value Th5 is added to each approximation formula.

[0115] In this way, in the fifth embodiment, the temperature sensor 5 -1 ~5 -6 By performing a regression analysis for each temperature sensor individually, the -1 ~5 -6 14(a) and (b) and the coefficient of determination "R 2 "reference). In the fifth embodiment, each temperature sensor 5 -1 ~5 -6 It can be said that the corresponding inclination threshold value is individually corrected depending on the left-right position of one brake device relative to another brake device on the axles 3a to 3c of the vehicle, that is, the position of the brake device 10 provided on each axle 3a to 3c of the vehicle.

[0116] As described above, the calculation unit 30 of the fifth embodiment calculates the temperature of the corresponding temperature sensor 5 according to the left-right position of one brake device and another brake device on the axles 3a to 3c. -1 ~5 -6 The slope thresholds (for example, Th5, Th6, and Th7) individually calculated from the above are corrected. According to this, since the level and magnitude of fluctuation of the brake temperature T tend to differ for each brake device 10 (see, for example, FIG. 8), for example, the gradient thresholds Th5, Th6, and Th7 used for comparison with the temperature gradient ΔT of each brake device 10 are set to the corresponding temperature sensors 5 -1 ~5 -6 The temperature sensor 5 can be corrected to a value calculated individually from the temperature sensor 5, thereby mitigating the influence of differences in the temperature characteristics of the individual brake devices 10 corresponding to the longitudinal position of the axles 3a to 3c or the lateral position of the axles 3a to 3c, and preventing the temperature sensor 5 from detecting a sensor disconnection abnormality even when the temperature sensor 5 is not disconnected.

[0117] FIG. 15 shows a plot diagram of the sixth embodiment, which differs from the plot diagram of FIG. 14 described above in that the average value of the relative temperature during the past driving period is taken on the x-axis. That is, in the plots of Figures 15(a)(b)..., the average value of the relative temperature, which is the difference between the brake temperature T and the outside air temperature during the past driving period, is taken on the x-axis, the maximum value of the temperature gradient ΔT is taken on the y-axis, and the temperature sensor 5 -1 ~5 -6 The plot for the most recent predetermined number of trips is made for each temperature sensor 5. -1 , 5 -2 , ... are expressed separately.

[0118] In this case, the temperature sensor 5 -1 , 5 -2 The regression equations for (a), (b), ... are given by the approximate equations of the approximate straight lines shown by the dashed lines in FIG. Therefore, the corrected slope threshold values ​​Th5', Th5', ... shown in Figs. 15(a) and 15(b) are obtained by using the temperature sensor 5 -1 , 5 -2 , ..., the "average value of relative temperature (brake temperature T - outside air temperature) during the past driving period" is substituted, and the slope threshold value Th5 is added to each approximate formula.

[0119] Therefore, as is clear from a comparison of Figs. 15(a)(b)... and Fig. 14(a)(b)..., it can be said that the relative temperature obtained by subtracting the outside air temperature from the brake temperature T as in the sixth embodiment has a higher correlation with the fluctuation range of the temperature gradient ΔT (the coefficient of determination "R 2 "reference).

[0120] Therefore, the gradient threshold values ​​(for example, Th5, Th6, and Th7 in FIG. 7) in the sixth embodiment are set to the braking device 10 -1 ~10 -6 Based on the relative temperature difference between each brake temperature T and the outside air temperature, the temperature sensor 5 -1 ~5 -6 Since the outside temperature is calculated every time, the braking system -1 ~10 -6 This can be said to contribute more to mitigating the influence of temperature fluctuations on the brake device 10. -1 ~10 -6 In this case, the corresponding gradient threshold value can be individually corrected according to each position, and the same effects as those of the above-described embodiment can be obtained.

[0121] Next, a seventh embodiment will be described with reference to FIGS. 4, 5 to 7, and the like. The abnormality detection device 1 of the seventh embodiment is configured to correct the tilt threshold values ​​(e.g., Th5, Th6, and Th7 in FIG. 7) according to the vehicle speed, acceleration, or braking state of the vehicle based on the brake signal of the brake sensor, the vehicle speed signal of the vehicle speed sensor, the acceleration signal of the tilt sensor (see reference numerals 331 to 333 in FIG. 4), etc.

[0122] Specifically, when executing the determination processing of FIGS. 5 to 7, the abnormality detection device 1 executes the following processing. That is, first, the abnormality detection device 1 acquires a vehicle speed signal, a brake signal, and an acceleration signal via the vehicle information acquisition unit 303. The vehicle information acquired at this time includes a braking period (a period during which the vehicle speed is decelerating), which is an on-period of the brake signal.

[0123] Next, the abnormality detection device 1 calculates a calculation period according to the vehicle speed as one of various parameters. The calculation period is set to be shorter as the vehicle speed is higher, for example, 10 seconds at a speed of 50 km / h. Furthermore, the vehicle braking state is calculated as a proportion of the braking period in the calculation period, and the braking period does not include a stop period in which the vehicle is stopped even though the brake signal is on.

[0124] Then, the abnormality detection device 1 calculates corrected slope threshold values ​​Th5', Th6', and Th7' according to the proportion of the braking period in the calculation period. For example, the braking period percentage is divided into 10% or more but less than 30%, 30% or more but less than 50%, 50% or more but less than 70%, 70% or more but less than 90%, and 90% or more, and the slope thresholds Th5, Th6, and Th7 are corrected to values ​​of 1.2 times, 1.4 times, 1.6 times, 1.8 times, and 2.0 times according to these divisions.

[0125] Next, the abnormality detection device 1 determines whether the braking was performed while the vehicle was traveling at high speed, based on a predetermined threshold value of the vehicle speed (for example, 60 (km / h)). For example, if it is determined that the vehicle was braked at a speed of less than 60 km / h, the slope threshold corrected according to the above classification is set as the corrected slope thresholds Th5', Th6', and Th7'. On the other hand, if it is determined that the vehicle was braked at a high speed of 60 km / h or more, the slope threshold corrected according to the above classification is further multiplied by 1.5 and set as the corrected slope thresholds Th5', Th6', and Th7'.

[0126] In this way, the abnormality detection device 1 performs the process of correcting the slope thresholds Th5, Th6, and Th7 based on the proportion of the braking period and the vehicle speed of the vehicle, for example, in S21 before executing S22, S24, and S26 in Figure 7, and if the proportion of the braking period is greater than or equal to 0% and less than 10% and the vehicle speed is less than 60 (km / h), the process of S22, S24, and S26 is executed without correcting the slope thresholds Th5, Th6, and Th7. It is to be noted that either the correction process according to the proportion of the braking period or the correction process according to the vehicle speed may be performed alone, or may be performed together with the correction process according to the acceleration.

[0127] The abnormality detection device 1 detects the lateral acceleration and the longitudinal acceleration based on the acceleration signal, and obtains the acceleration period (acceleration state) excluding the period when the vehicle is stopped. The acceleration period is a period during which the lateral acceleration when the vehicle is traveling around a curve, or the longitudinal acceleration that occurs during acceleration or deceleration, is continuously equal to or greater than the respective predetermined threshold values.

[0128] Then, the abnormality detection device 1 calculates the ratio of the acceleration period to the calculation period, and calculates corrected slope thresholds Th5', Th6', and Th7' according to the ratio of the acceleration period. For example, the acceleration period ratio is divided into multiple categories, similar to the braking period ratio, and the slope thresholds Th5, Th6, and Th7 are corrected according to the category so that the longer the acceleration period, the larger the slope thresholds Th5, Th6, and Th7 become. Note that the slope thresholds to be corrected are not limited to Th5 to Th7, and the other thresholds Th1 to Th4 can also be corrected.

[0129] As described above, the calculation unit 30 of the seventh embodiment corrects the tilt threshold value in accordance with the vehicle speed, acceleration, or braking state of the vehicle. In this regard, the temperature gradient ΔT tends to increase or decrease depending on the vehicle speed or braking state. However, for example, the gradient threshold values ​​(e.g., Th5, Th6, Th7) used for comparison with the temperature gradient ΔT of a brake device can be corrected to values ​​corresponding to the vehicle speed or braking state of the vehicle, thereby mitigating the effects of the vehicle speed or braking state.

[0130] Furthermore, when the vehicle is curved, accelerating, or decelerating, air outside the vehicle is likely to enter the brake device, or the brake temperature may fluctuate due to the influence of wind from the vehicle running, etc., but the slope threshold can be corrected to correspond to the acceleration state, thereby mitigating the influence of wind from the vehicle running, etc.

[0131] The present disclosure is not limited to the above-described embodiments, and may be modified or expanded as follows, or each modified example or the above-described embodiments may be combined. The abnormality detection device 1 is not limited to being mounted on vehicles α and β such as the trailer 2, but may also be mounted on automobiles such as trucks and buses. Information other than the brake temperature T (for example, image information captured by a camera, not shown) may be used as detection information relating to the installation state of the temperature sensor 5. In any case, when temperature fluctuations in the brake temperatures of one brake device and another brake device are detected during the same time period, they can be excluded from the determination of sensor disconnection abnormality as an effect of vehicle travel.

[0132] The anomaly detection device 1 and the calculation unit 30 described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor and memory programmed to execute one or more functions embodied in a computer program. Alternatively, the anomaly detection device 1, the calculation unit 30, and the method thereof described in the present disclosure may be implemented by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits.

[0133] Alternatively, the anomaly detection device 1, the computing unit 30, and the method thereof described herein may be implemented by one or more dedicated computers configured by combining a processor and memory programmed to perform one or more functions with a processor configured by one or more hardware logic circuits. Also, the computer program may be stored on a computer-readable non-transitory tangible storage medium as instructions to be executed by the computer.

[0134] Although the present invention has been described based on the above-described embodiment, it is understood that the present invention is not limited to the embodiment or structure. The present invention also encompasses various modifications and modifications within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms including one, more, or less than one element, are also within the scope and spirit of the present invention. [Explanation of symbols]

[0135] In the drawing, 1 is an abnormality detection device, 2 is a trailer (vehicle), 3, 3a to 3c are axles (front axle, middle axle, rear axle), 5, 5 -1 ~5 -6 is the temperature sensor, 10,10 -1 ~10 -6 denotes a brake device, and 30 denotes a calculation unit (temperature acquisition unit, abnormality detection unit, calculation unit, correction unit).

Claims

1. a temperature acquisition unit (30) that acquires brake temperatures, which are temperatures of the respective brake devices, based on detection signals from a plurality of temperature sensors (5) that are respectively attached to a plurality of brake devices (10) in the vehicle (2); an abnormality detection unit (30) for detecting an abnormality in the mounting state of each temperature sensor as an detached abnormality; Equipped with The abnormality detection unit executes a process of determining the disconnection abnormality for each temperature sensor based on detection information related to the installation state, including the brake temperature, and when temperature fluctuations in the brake temperature of one brake device and another brake device among the plurality of brake devices are detected during the same time period, the abnormality detection device excludes the temperature fluctuations from the determination of the disconnection abnormality as being due to the influence of the vehicle's driving.

2. The brake devices are provided on both left and right ends of each axle (3) of the vehicle, The abnormality detection device according to claim 1, wherein the other brake device is at least one brake device on the same left-right side as the first brake device.

3. The brake devices are provided on both left and right ends of each axle of the vehicle, 2. The abnormality detection device according to claim 1, wherein the other brake device is on the same axle as the first brake device.

4. The abnormality detection unit A calculation unit (30) is provided that calculates a temperature gradient based on the brake temperature acquired by the temperature acquisition unit with respect to the temperature fluctuation, and is configured to determine that the disconnection abnormality has occurred when the temperature gradient for only the one brake device is equal to or greater than a preset gradient threshold value; 2. The abnormality detection device according to claim 1, further comprising a correction unit (30) that corrects the slope threshold value in accordance with the vehicle speed, acceleration, or braking state of the vehicle.

5. The abnormality detection unit The temperature sensor is configured to include a calculation unit that calculates a temperature gradient based on the brake temperature acquired by the temperature acquisition unit for the temperature fluctuation, and to determine that the disconnection abnormality has occurred when the temperature gradient for only the one brake device is equal to or greater than a preset gradient threshold value; The abnormality detection device according to claim 1 , further comprising a correction unit that corrects the slope threshold value in accordance with the level of the brake temperature.

6. The abnormality detection unit The temperature sensor is configured to include a calculation unit that calculates a temperature gradient based on the brake temperature acquired by the temperature acquisition unit for the temperature fluctuation, and to determine that the disconnection abnormality has occurred when the temperature gradient for only the one brake device is equal to or greater than a preset gradient threshold value; 2. The abnormality detection device according to claim 1, further comprising a correction unit that corrects the gradient threshold value in accordance with a relative temperature difference between the brake temperature and an outside air temperature that is a temperature outside the vehicle.

7. The abnormality detection unit The temperature sensor is configured to include a calculation unit that calculates a temperature gradient based on the brake temperature acquired by the temperature acquisition unit for the temperature fluctuation, and to determine that the disconnection abnormality has occurred when the temperature gradient for only the one brake device is equal to or greater than a preset gradient threshold value; 2. The abnormality detection device according to claim 1, further comprising a correction unit that corrects the inclination threshold value according to the position of the brake device provided on each axle of the vehicle, the position of the one brake device relative to the other brake device in the left-right direction on the axle.

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