Large vehicle braking system and method

Abstract

A method for measuring the thickness of a braking component in a brake assembly for a heavy vehicle, wherein the brake assembly for a heavy vehicle comprises a braking element including a friction material having an engagement surface, and the braking element is configured to decelerate the heavy vehicle by engaging the engagement surface of the friction material with the braking surface of the braking component when actuated during braking. The method includes determining whether an ultrasonic device having an ultrasonic emitter is in an engaged state, in contact with the braking surface; when the ultrasonic device is in an engaged state, emitting high-frequency sound waves through the braking component with the ultrasonic emitter, detecting the high-frequency sound waves with an ultrasonic sensor; and calculating the thickness of the braking component based on the time delay between the emission and detection of the high-frequency sound waves.

Description

Technical Field

[0001] The present disclosure relates to a large vehicle braking system, a control device, a parts kit, instructions readable by the control device, and methods for detecting wear, measuring the temperature of a braking element, and determining the braking state of a brake assembly for a large vehicle.

Background Art

[0002] It is known to provide a brake assembly for a large vehicle comprising a braking element including a friction material having an engagement surface with a braking component, the braking element being configured to be actuated in a braking operation such that the engagement surface of the friction material engages the braking surface of the braking component to decelerate the large vehicle.

[0003] There are various methods for detecting wear in such a brake assembly for a large vehicle. Such a system is an important safety feature and helps to ensure that the braking element and / or the braking surface are replaced before they wear too much to provide effective braking force. This can prevent accidents and enhance the overall safety of the vehicle. Further, by detecting wear early, such a system helps to reduce maintenance costs by enabling the braking element and / or the braking surface to be replaced before they damage other parts of the braking system.

[0004] In some brakes, a constant wear sensor (CWS) is provided. Known CWS systems measure internal components of the brake to estimate total friction wear. For example, in a disc brake, the CWS measures the total number of rotations of an adjustment mechanism to estimate total wear, which consists of wear of the inboard brake pad, the outboard brake pad, and the brake rotor in the vehicle width direction.

[0005] However, it is desirable to provide real-time measurement of wear of individual braking elements and braking surfaces, which can be useful for diagnosing problems with the brake such as differential wear.

[0006] Furthermore, it is known that when braking elements and braking components are engaged with each other during braking (for example, in "dynamic" braking where there is relative motion between the braking elements and braking components), the temperatures of the braking elements and braking components rise. Therefore, it is sometimes desirable to detect the temperature of the braking elements and / or braking components in order to determine the braking state of a brake assembly for a large vehicle.

[0007] The objective of this invention is to solve one or more of the disadvantages associated with the prior art. [Overview of the Initiative]

[0008] Aspects and embodiments of the present invention provide a method for measuring the thickness of braking components in a brake assembly for a heavy vehicle, a method for determining the braking state of a brake assembly for a heavy vehicle, a method for measuring the temperature of braking elements in a brake assembly for a heavy vehicle, a heavy vehicle braking system, a disc brake, a drum brake, and a control device according to the appended claims.

[0009] One aspect of the disclosure provides a method for measuring the thickness of a braking component in a heavy vehicle brake assembly of a type that includes a braking element having an engagement surface, wherein the braking element is actuated in a braking operation so that the engagement surface of the friction material engages with a braking component to decelerate the heavy vehicle. The method includes: a) providing an ultrasonic device having an ultrasonic emitter, the ultrasonic device being movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface and an engaged state in which the ultrasonic device is in contact with the braking surface; b) determining that the ultrasonic device is in the engaged state; c) when it is determined that the ultrasonic device is in the engaged state, emitting a high-frequency sound wave through the braking component with the ultrasonic emitter and detecting the high-frequency sound wave with an ultrasonic sensor; d) measuring the time delay between the emission and detection of the high-frequency sound wave; and e) calculating the thickness of the braking component based on the time delay.

[0010] It is understood that braking components (e.g., disc brake rotors) typically wear at a different rate than the friction material of the braking element (e.g., brake pads), and therefore require replacement at different times. Consequently, it is difficult to reliably determine the wear of braking components using existing CWS systems that estimate only overall wear and not the wear of individual braking elements or components. Therefore, having a method that can directly measure the thickness of braking components offers advantages over known wear detection systems in that it allows for the determination of braking component thickness independently of other parts of the brake assembly (e.g., braking elements).

[0011] When the ultrasonic device is engaged, it is understood that the operating clearance between the braking surface and the ultrasonic device is zero. In other words, there is no gap or air gap between the ultrasonic device and the braking surface.

[0012] Conversely, when the ultrasonic device is disengaged, it is understood that the operating clearance between the braking surface and the ultrasonic device is greater than zero. In other words, there is a gap or air gap between the ultrasonic device and the braking surface.

[0013] Optionally, the damping surface and the ultrasonic device have complementary engaging surfaces configured to contact each other. Optionally, the complementary engaging surfaces are planar. Optionally, the complementary engaging surfaces are curved. Optionally, the complementary engaging surfaces are complementary convex and concave surfaces (e.g., a convex surface of the ultrasonic device for engaging with a complementary concave surface of the damping surface). When the ultrasonic device is disengaged, it is understood that the ultrasonic device and the damping surface are separated from each other by a gap or air gap between the complementary engaging surfaces. Conversely, when the ultrasonic device is engaged, there is no gap or air gap between the complementary engaging surfaces.

[0014] Optionally, the ultrasonic emitter and / or ultrasonic sensor are fixed relative to the damping element. Optionally, the ultrasonic emitter and / or ultrasonic sensor are rigidly fixed to the damping element.

[0015] In this way, the ultrasonic emitter and / or ultrasonic sensor can be moved toward the braking surface during the braking operation, making it easier to measure the thickness of the braking components.

[0016] Optionally, the ultrasonic emitter and / or ultrasonic sensor are fixed to the damping element.

[0017] Optionally, the ultrasonic device includes an ultrasonic sensor. In such embodiments, it is understood that high-frequency sound waves emitted by the ultrasonic emitter are reflected at boundaries between different densities (e.g., between the distal side of a braking component opposite the braking surface and the air gap or the boundary between opposing braking components). The thickness can be calculated using the time delay between the emission of the high-frequency sound waves and the reception of the reflected sound waves.

[0018] Optionally, the ultrasonic device has a housing for the ultrasonic emitter.

[0019] Optionally, the ultrasonic device includes a spacing member that separates the ultrasonic emitter from the damping surface when the ultrasonic device is engaged.

[0020] Optionally, the spacing member includes part of the housing for the ultrasonic emitter and / or a sacrificial member.

[0021] Optionally, the spacing member is configured to directly contact the braking surface when the ultrasonic device is engaged. In other words, the spacing member forms an engagement surface that engages with a complementary engagement surface of the braking surface when the ultrasonic device is engaged.

[0022] Optionally, an ultrasonic device having an ultrasonic emitter is a first ultrasonic device located on a first side of a braking component, and an ultrasonic sensor is part of a second ultrasonic device located on a second side of a braking component opposite to the first side, the braking components each having first and second braking surfaces on the first and second sides, the second ultrasonic device is movable between an unengaged state in which the second ultrasonic device is not in contact with the second braking surface and an engaged state in which the second ultrasonic device is in contact with the second braking surface, and step b) includes determining that both the first and second ultrasonic devices are in an engaged state.

[0023] In this way, the first and second ultrasonic devices can be used in a "throw-and-catch" configuration, in which high-frequency sound waves are transmitted directly from the ultrasonic emitter of the first ultrasonic device to the ultrasonic sensor of the second ultrasonic device (i.e., not reflected by an ultrasonic sensor adjacent to the ultrasonic emitter).

[0024] Optionally, each of the first and second ultrasonic devices may have both an ultrasonic emitter and an ultrasonic sensor. In this way, the first and second ultrasonic devices can also be used independently of each other (for example, to measure wear of a braking element, as disclosed in European Patent Application EP23179290.4).

[0025] Optionally, the brake assembly is of a type comprising first and second braking elements, each containing a friction material having engaging surfaces, the first and second braking elements being actuated in a braking operation so that their engaging surfaces engage with the respective first and second braking surfaces to decelerate a heavy vehicle, the first ultrasonic device being fixed relative to the first braking element, and the second ultrasonic device being fixed relative to the second braking element.

[0026] In this way, the first and second ultrasonic devices can be moved toward their respective braking surfaces during the braking operation, thereby facilitating the measurement of the thickness of the braking components.

[0027] Optionally, the first ultrasonic device is firmly fixed to the first braking element, and the second ultrasonic device is firmly fixed to the second braking element.

[0028] Optionally, the first ultrasonic device is fixed to the first braking element, and the second ultrasonic device is fixed to the second braking element.

[0029] Optionally, step b) includes determining that the engagement surfaces of the braking element or the friction material of each braking element are in contact with the corresponding braking surfaces, respectively.

[0030] When the ultrasonic emitter and / or the ultrasonic sensor is relatively fixed to the braking element, determining that the engagement surfaces of the braking element or the friction material of each braking element are in contact with the corresponding braking surfaces, respectively (i.e., determining that the braking operation is being performed), can provide a simple means for determining that the ultrasonic device or each ultrasonic device is in an engaged state.

[0031] Optionally, step b) includes sending a command to the brake control system to activate the braking element or each braking element to engage with the corresponding braking surface. Sending a command to activate the braking element or each braking element provides a simple means for determining that the engagement surfaces of the braking element or the friction material of each braking element are in contact with the corresponding braking surfaces, respectively (i.e., determining that the braking operation is being performed).

[0032] Optionally, the brake control system has a split brake system. The split brake system provides means for activating the braking element or each braking element as commanded.

[0033] Optionally, the command is sent to the brake control system when the heavy vehicle is started. Since the brakes are normally applied when the heavy vehicle is started, it is understood that there is no adverse effect in commanding the brakes to be applied temporarily at startup while thickness measurement is being performed (compared to, for example, commanding the brakes to be applied during driving, which could pose a safety risk).

[0034] Optionally, step b) includes receiving a signal from a brake pedal sensor and / or a brake control system. Receiving a signal from the brake pedal sensor and / or brake control system provides a reliable means of determining whether the engaging surfaces of the braking elements or the friction material of each braking element are in contact with the corresponding braking surfaces. For example, the control device may be an ECU associated with a separate braking system.

[0035] Optionally, step b) includes measuring the pressure in a hydraulic or pneumatic brake line connected to a braking element or an actuator for acting on each braking element. In a hydraulic / pneumatic brake system, it is understood that the pressure in the hydraulic or pneumatic brake line increases when a braking action is performed compared to when no braking action is being performed. Therefore, measuring the pressure in such a brake line provides a reliable means of determining whether the engaging surfaces of the friction material of the braking element or each braking element are in contact with the corresponding braking surface.

[0036] Optionally, step b) includes identifying changes in high-frequency sound waves detected by an ultrasonic sensor. It is understood that the output of the ultrasonic sensor differs when the braking element or the engagement surface of the friction material of each braking element is in contact with the braking surface and when it is not. Therefore, when the braking element or the engagement surface of each braking element changes from a state of not being in contact with the braking surface to a state of contact (for example, as a result of a braking action being performed), a rapid change occurs in the output of the ultrasonic sensor. Such a rapid change can be used to determine that the braking element or the engagement surface of the friction material of each braking element is in contact with the corresponding braking surface.

[0037] Optionally, step b) includes measuring the current in an electrical circuit connected to a braking element or an electric actuator for acting on each braking element. In an electric braking system, it is understood that when a braking action is performed, the current in the associated electrical circuit changes. Therefore, measuring the current in such an electrical circuit provides a reliable means for determining whether the engaging surfaces of the friction material of the braking element or each braking element are in contact with the corresponding braking surface.

[0038] Optionally, the method includes f) determining the wear state of the braking component based on the change in the thickness of the braking component over time. By such a step f) utilizing the thickness calculated in step e), the wear of the braking component can be determined independently of the wear of other parts of the brake assembly (e.g., braking elements).

[0039] Optionally, step f) includes comparing the thickness of the braking component calculated in step e) with a reference thickness stored in memory, the reference thickness including the initial thickness of the braking component and / or the thickness of one or more previously calculated braking components. By comparing with such a reference thickness stored in memory, it is possible to determine the change in thickness over time, thereby obtaining an indicator of the wear state of the braking component.

[0040] Optionally, the method further includes audibly and / or visually indicating the wear condition determined in step f). By audibly and / or visually indicating the wear condition (for example, via an indicator placed inside the cabin of a large vehicle), the driver or maintenance technician can understand the wear condition of the braking components and take appropriate action as necessary.

[0041] Optionally, the method further includes recording the wear condition determined in step f) in memory. By recording the wear condition in memory, the wear trend over time can be tracked.

[0042] Optionally, the method further includes transmitting the wear condition determined in step f) to a wear monitoring system. By transmitting (e.g., transmitting) the wear condition to the wear monitoring system, users of the wear monitoring system can take appropriate action. For example, if a company operates a fleet of heavy vehicles, the wear condition of each braking component of each vehicle is transmitted to a central wear monitoring system, which allows the company to schedule maintenance on specific vehicles (i.e., replacement of worn braking components) as needed.

[0043] Optionally, the method includes g) determining the wear condition of a braking component based on the difference between the calculated thickness of the braking component and the calculated thickness of another braking component of the same vehicle.

[0044] Optionally, step g) includes determining that a braking component is prematurely worn if the calculated thickness of the braking component is lower than a threshold value compared to the calculated thickness of another braking component of the same vehicle.

[0045] Optionally, the method further includes audibly and / or visually displaying the wear condition determined in step g), and / or recording the wear condition determined in step g) in memory, and / or transmitting the wear condition determined in step g) to a wear monitoring system.

[0046] Optionally, the method further includes audibly and / or visually indicating the thickness of the braking component calculated in step e). By audibly and / or visually indicating the thickness of the braking component (for example, via an indicator placed inside the cabin of a large vehicle), a driver or maintenance technician can be aware of the thickness of the braking component and take appropriate action as necessary.

[0047] Optionally, the method further includes recording the thickness of the braking component calculated in step e) in memory. By recording the thickness of the braking component in memory, changes in thickness over time can be tracked.

[0048] Optionally, the method further includes transmitting the thickness of the braking components calculated in step e) to a thickness monitoring system. By transmitting (e.g., transmitting) the thickness of the braking components to the thickness monitoring system, users of the thickness monitoring system can take appropriate action. For example, if a company operates a fleet of large vehicles, the thickness of each braking component in each vehicle is transmitted to a central thickness monitoring system, which allows the company to schedule maintenance on specific vehicles as needed (i.e., replacement of braking components that have become too thin).

[0049] Optionally, the method further includes determining the temperature of the brake assembly and calibrating the calculation in step e) using the determined temperature of the brake assembly. It is understood that ultrasonic sensor readings can vary with temperature. Therefore, by determining the temperature and using it to calibrate the calculation in step e), an accurate measurement of the thickness of the braking component can be obtained.

[0050] Optionally, the temperature of the brake assembly can be determined using a temperature sensor and / or by monitoring the operating conditions of the brake assembly (for example, to estimate the temperature based on the duration of the braking action).

[0051] Optionally, the method further includes determining whether the temperature of the brake assembly is within a predetermined temperature range, and step c) is performed only when it is determined that the temperature of the brake assembly is within the predetermined temperature range. It is understood that ultrasonic sensor readings can vary with temperature. Therefore, by determining whether the temperature of the brake assembly is within a predetermined temperature range (e.g., the temperature range for which the calculation in step e) is calibrated) and performing step c) only within this temperature range, an accurate measurement of the thickness of the braking component can be obtained.

[0052] Optionally, determining whether the temperature of the brake assembly is within a predetermined temperature range includes determining that a predetermined time has elapsed since the last braking operation. It is understood that the temperature of the brake assembly rises during braking due to frictional force, and after the braking operation is completed, this temperature gradually decreases toward ambient temperature. Therefore, determining that a predetermined time has elapsed since the last braking operation provides a means for determining whether the temperature is within a predetermined range (for example, a range close to the range of typical atmospheric conditions).

[0053] Optionally, determining whether the brake assembly temperature is within a predetermined temperature range includes determining when a heavy vehicle was started after a period of inactivity. When a heavy vehicle is started after a period of inactivity, the brake assembly temperature approaches that of ambient conditions. Furthermore, it is understood that the temperature fluctuations between different starting events under different ambient conditions are relatively low compared to the temperatures reached during prolonged braking operations. Therefore, determining when a heavy vehicle is started provides an alternative means of determining whether the temperature is within a predetermined range.

[0054] Optionally, determining whether the temperature of the brake assembly is within a predetermined temperature range includes measuring or estimating the temperature of the brake assembly using a temperature sensor. By using a temperature sensor, the measured temperature is obtained, and this can be used to easily determine whether the temperature of the brake assembly is within a predetermined range.

[0055] Further aspects of this teaching provide a method for determining the braking state of a heavy vehicle brake assembly of a type that includes a braking element having a friction material having an engagement surface, wherein the braking element is actuated in a braking operation so that the engagement surface of the friction material engages with a braking surface of a braking component to decelerate the heavy vehicle, the method comprising: a) providing an ultrasonic device having an ultrasonic emitter, the ultrasonic device being movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface and an engaged state in which the ultrasonic device is in contact with the braking surface; b) emitting high-frequency sound waves through a braking component using the ultrasonic emitter and detecting the high-frequency sound waves with an ultrasonic sensor; and c) determining the braking state of the heavy vehicle brake assembly by identifying changes in the high-frequency sound waves detected by the ultrasonic sensor.

[0056] Optionally, the ultrasonic device is assumed to be fixed to the braking element, and step c) includes determining when the braking element is in contact with the braking surface of the braking component by identifying an increase in the amplitude of a high-frequency sound wave detected by the ultrasonic sensor.

[0057] Optionally, the method further includes the step of determining that the braking element is in a dragging state when it is determined in step c) that the braking element is in contact with the braking surface and the brake assembly for heavy vehicles is not performing a braking operation.

[0058] Further aspects of this teaching provide a heavy vehicle braking system comprising a heavy vehicle brake assembly, an ultrasonic device, an ultrasonic sensor, and a control device, wherein the heavy vehicle brake assembly comprises a braking element including a friction material having an engagement surface, the braking element being activated in a braking operation so that the engagement surface of the friction material engages with the braking surface of the braking element to decelerate the heavy vehicle, the ultrasonic device includes an ultrasonic emitter, the ultrasonic device is movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface and an engaged state in which the ultrasonic device is in contact with the braking surface, and the control device is configured to determine the braking state of the heavy vehicle brake assembly by a) instructing the ultrasonic emitter to emit high-frequency sound waves through the braking element so that the high-frequency sound waves are detected by an ultrasonic sensor, receiving a signal from the ultrasonic sensor indicating the detected high-frequency sound waves, and b) identifying changes in the high-frequency sound waves detected by the ultrasonic sensor.

[0059] Optionally, the ultrasonic device is fixed relative to the braking element, and the control device is configured to determine in step b) when the braking element is in contact with the braking surface of the braking component by identifying an increase in the amplitude of the high-frequency sound wave detected by the ultrasonic sensor.

[0060] Optionally, the control device is configured to determine that the braking element is in a dragging state when it is determined in step b) that the braking element is in contact with the braking surface and that the brake assembly for heavy vehicles is not performing a braking operation.

[0061] A further aspect of this teaching provides a control device for a brake system for heavy vehicles. The control device is configured to determine the braking state of the heavy vehicle brake assembly by a) instructing an ultrasonic emitter to emit high-frequency sound waves through the braking components of the heavy vehicle brake assembly and to detect the high-frequency sound waves by an ultrasonic sensor, receiving a signal from the ultrasonic sensor indicating the detected high-frequency sound waves, and b) identifying changes in the high-frequency sound waves detected by the ultrasonic sensor.

[0062] Optionally, the control device is configured to determine in step b) when the braking element is in contact with the braking surface of the braking component of the brake assembly for a heavy vehicle by identifying an increase in the amplitude of a high-frequency sound wave detected by the ultrasonic sensor.

[0063] Optionally, the control device is configured to determine that the braking element is in a dragging state when it is determined in step b) that the braking element is in contact with the braking surface and that the brake assembly for heavy vehicles is not performing a braking operation.

[0064] Further aspects of this teaching provide a heavy vehicle braking system comprising a heavy vehicle brake assembly, an ultrasonic device, an ultrasonic sensor, and a control device, wherein the heavy vehicle brake assembly comprises a braking element including a friction material having an engagement surface, the braking element being activated in a braking operation so that the engagement surface of the friction material engages with the braking surface of the braking element to decelerate the heavy vehicle, the ultrasonic device having an ultrasonic emitter, the ultrasonic device being movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface and an engaged state in which the ultrasonic device is in contact with the braking surface, and the control device being configured to a) determine that the ultrasonic device is in the engaged state, b) when it is determined that the ultrasonic device is in the engaged state, command the ultrasonic emitter to emit high-frequency sound waves through the braking element so that they can be detected by an ultrasonic sensor, receive a signal from the ultrasonic sensor indicating the detected high-frequency sound waves, c) measure the time delay between the emission and detection of the high-frequency sound waves, and d) calculate the thickness of the braking element based on the time delay.

[0065] Such large-vehicle braking systems offer the advantages of the methods described above.

[0066] Optionally, the control device is further configured to e) determine the wear status of the braking components based on changes in the thickness of the braking components over time. That is, the control device automatically determines the wear status (e.g., "worn and needs to be replaced soon," or "partially worn but does not need to be replaced") without anyone needing to directly monitor the thickness of the braking components. Alternatively, the control device may only calculate the thickness, and the wear status may be determined manually (e.g., by a maintenance technician) based on the calculated thickness. Optionally, the control device is configured in step e) to compare the thickness of the braking components calculated in step d) with a reference thickness stored in memory, the reference thickness including the initial thickness of the braking components and / or the thickness of one or more previously calculated braking components. Optionally, the heavy vehicle braking system has memory.

[0067] Optionally, the ultrasonic emitter and / or ultrasonic sensor are fixed relative to the braking element. In this way, the ultrasonic emitter and / or ultrasonic sensor can be moved toward the braking surface during braking, thereby facilitating measurement of the thickness of the braking component.

[0068] Optionally, the ultrasonic emitter and / or ultrasonic sensor are fixed to the damping element.

[0069] Optionally, the ultrasonic apparatus includes an ultrasonic sensor. In such embodiments, it is understood that high-frequency sound waves emitted from the ultrasonic emitter are reflected at boundaries between different densities (e.g., the boundary between the distal side of a braking component opposite the braking surface and the air gap or between opposing braking elements). The time delay between the emission of the high-frequency sound waves and the reception of the reflected sound waves can be used by the control device to calculate the thickness.

[0070] Optionally, the ultrasonic device has a housing for the ultrasonic emitter.

[0071] Optionally, the ultrasonic device has a spacing member that separates the ultrasonic emitter from the damping surface when the ultrasonic device is engaged.

[0072] Optionally, the spacing member includes part of the housing for the ultrasonic emitter and / or a sacrificial member.

[0073] Optionally, the spacing member is configured to directly contact the braking surface when the ultrasonic device is engaged. In other words, the spacing member forms an engagement surface that engages with a complementary engagement surface of the braking surface when the ultrasonic device is engaged.

[0074] Optionally, the ultrasonic device having an ultrasonic emitter is a first ultrasonic device located on the first side of the braking component, and the ultrasonic sensor is part of a second ultrasonic device located on the second side of the braking component, which is opposite to the first side, and the braking component has first and second braking surfaces on the first and second sides, respectively, and the second ultrasonic device is movable between an unengaged state in which the second ultrasonic device is not in contact with the second braking surface and an engaged state in which the second ultrasonic device is in contact with the second braking surface, and the control device is configured to determine in step a) that both the first and second ultrasonic devices are in the engaged state.

[0075] In this way, the first and second ultrasonic devices can be used in a "throw-and-catch" configuration, in which high-frequency sound waves are transmitted directly from the ultrasonic emitter of the first ultrasonic device to the ultrasonic sensor of the second ultrasonic device (i.e., not reflected by an ultrasonic sensor adjacent to the ultrasonic emitter).

[0076] Optionally, each of the first and second ultrasonic devices may have both an ultrasonic emitter and an ultrasonic sensor. In this way, the control device may also use the first and second ultrasonic devices independently of each other (for example, to measure wear of a braking element, as disclosed in European Patent Application EP23179290.4).

[0077] Optionally, a brake assembly for a heavy vehicle comprises first and second braking elements, each including a friction material having an engaging surface, the first and second braking elements being actuated in a braking operation so that their engaging surfaces engage with the corresponding first and second braking surfaces to decelerate the heavy vehicle, the first ultrasonic device being fixed relative to the first braking element, and the second ultrasonic device being fixed relative to the second braking element.

[0078] In this way, the first and second ultrasonic devices can be moved toward their respective braking surfaces during the braking operation, thereby facilitating the measurement of the thickness of the braking components.

[0079] Optionally, the first ultrasonic device is fixed to the first damping element, and the second ultrasonic device is fixed to the second damping element.

[0080] Optionally, the control device is configured to determine in step a) whether the braking element or the engagement surface of the friction material of each braking element is in contact with the corresponding braking surface.

[0081] Optionally, the control device is configured to transmit a command to the brake control system in step a) to actuate the braking element or each braking element to engage with the corresponding braking surface. Optionally, the brake control system has a separate braking system. Optionally, the control device is configured to transmit a command to the brake control system when a large vehicle is started.

[0082] Optionally, the control device is configured to receive signals from the brake pedal sensor and / or the brake control system in step a).

[0083] Optionally, the control device is configured to measure the pressure in the braking element or the hydraulic or pneumatic brake line connected to each braking element in step a). Optionally, the control device is configured to measure the pressure with a pressure sensor. Optionally, the heavy vehicle braking system has a pressure sensor. Optionally, the pressure sensor is part of an external system (e.g., a separate brake system).

[0084] Optionally, the control device is configured to identify changes in high-frequency sound waves detected by the ultrasonic sensor in step a).

[0085] Optionally, the control device is configured to measure the current in an electrical circuit connected to a braking element or an electrical actuator for operating each braking element in step a).

[0086] Optionally, the control unit is mounted on a brake assembly for heavy vehicles. In this way, the heavy vehicle braking system can be provided as a single unit.

[0087] The control device is optionally configured to determine the temperature of the brake assembly and to use the determined temperature of the brake assembly to calibrate the calculation in step d).

[0088] Optionally, the control device is configured to determine the temperature of the brake assembly based on signals received from a temperature sensor and / or by monitoring the operating conditions of the brake assembly (for example, based on signals from a brake control system or other braking action sensors). Optionally, a heavy vehicle braking system may have a temperature sensor.

[0089] The control device is optionally configured to determine whether the temperature of the brake assembly is within a predetermined temperature range, and to execute step b) only when it is determined that the temperature of the brake assembly is within the predetermined temperature range.

[0090] Optionally, the control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by determining that a predetermined time has elapsed since the last braking operation.

[0091] Optionally, the control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by determining that the large vehicle has been started after a period of inactivity.

[0092] Optionally, the control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by measuring or estimating the temperature of the brake assembly based on a signal from a temperature sensor. Optionally, the temperature sensor is part of a large vehicle braking system.

[0093] Optionally, the control device is configured to transmit signals corresponding to the thickness of the braking component calculated in step d) and / or the wear condition determined in step e) to an audible and / or visual indicator. Optionally, the heavy vehicle braking system has an audible and / or visual indicator. Optionally, the indicator is part of an external system.

[0094] Optionally, the control device is configured to record the thickness of the braking component calculated in step d) and / or the wear condition determined in step e) in memory. Optionally, the heavy vehicle braking system has memory. Optionally, the memory is part of an external system.

[0095] Optionally, the control device is configured to transmit signals to the wear monitoring system corresponding to the thickness of the braking component calculated in step d) and / or the wear condition determined in step e). Optionally, the heavy-duty vehicle braking system has a wear monitoring system. Optionally, the wear monitoring system is part of an external system. Optionally, the signals are transmitted to the wear monitoring system via a transmitter (e.g., a wireless transmitter). Optionally, the heavy-duty vehicle braking system has a transmitter.

[0096] Further embodiments of this teaching provide a disc brake having a large vehicle braking system disclosed herein, wherein the braking surface is a rotor rotatably fixed to a vehicle wheel, and the braking elements or each braking element is a brake pad having a friction material, optionally the brake pad having a back plate, and the friction material being fixed to the back plate.

[0097] A further aspect of this teaching provides a control device for a brake system for heavy vehicles. The control device is configured to: a) determine that an ultrasonic device of a heavy vehicle brake system is in an engaged state in which the ultrasonic device is in contact with the braking surface of a braking component of the heavy vehicle brake system; b) when it is determined that the ultrasonic device is in an engaged state, instruct the ultrasonic emitter of the ultrasonic device to emit high-frequency sound waves through the braking component and to detect the high-frequency sound waves by an ultrasonic sensor of the heavy vehicle brake system; receive a signal from the ultrasonic sensor indicating the detected high-frequency sound waves; c) measure the time delay between the emission and detection of the high-frequency sound waves; and d) calculate the thickness of the braking component based on the time delay.

[0098] Optionally, the control device is configured to further (e) determine the wear status of the braking components based on changes in the thickness of the braking components over time. That is, the control device automatically determines the wear status (e.g., "worn and needs to be replaced soon," or "partially worn but does not need to be replaced") even if no one is directly monitoring the thickness of the braking components. Alternatively, the control device may only calculate the thickness, and the wear status may be determined manually (e.g., by a maintenance technician) based on the calculated thickness. Optionally, the control device is configured in step (e) to compare the thickness of the braking components calculated in step (d) with a reference thickness stored in memory, the reference thickness including the initial thickness of the braking components and / or the thickness of one or more previously calculated braking components.

[0099] Optionally, the control device is configured to determine in step a) that both a first ultrasonic device located on the first side of the braking component and a second ultrasonic device located on the second side of the braking component are in an engaged state in which the ultrasonic devices are in contact with the corresponding braking surfaces of the braking component.

[0100] In this way, the control device can be used in applications where the first and second ultrasonic devices are used in a "throw-and-catch" configuration, in which high-frequency sound waves are transmitted directly from the ultrasonic emitter of the first ultrasonic device to the ultrasonic sensor of the second ultrasonic device (i.e., not reflected by an ultrasonic sensor adjacent to the ultrasonic emitter).

[0101] Optionally, the control device is configured to determine in step a) whether the engagement surface of the friction material of the braking element is in contact with the corresponding braking surface of each braking component.

[0102] Optionally, the control device is configured in step a) to transmit a command to the brake control system to activate the braking elements and engage them with their respective braking surfaces. Optionally, the brake control system includes a separate braking system. Optionally, the control device is configured to transmit a command to the brake control system when a heavy vehicle is started.

[0103] Optionally, the control device is configured to receive signals from the brake pedal sensor and / or the brake control system in step a).

[0104] Optionally, the control device is configured to measure the pressure in a hydraulic or pneumatic brake line connected to the braking element in step a). Optionally, the control device is configured to measure the pressure with a pressure sensor. Optionally, the heavy vehicle braking system has a pressure sensor. Optionally, the pressure sensor is part of an external system (e.g., a separate brake system).

[0105] Optionally, the control device is configured to identify changes in high-frequency sound waves detected by the ultrasonic sensor in step a).

[0106] Optionally, the control device is configured to measure the current in an electrical circuit connected to a braking element or an electric actuator for operating each braking element in step a).

[0107] Optionally, the control unit is mounted on a brake assembly for heavy vehicles. In this way, the heavy vehicle braking system can be provided as a single unit.

[0108] The control device is optionally configured to determine the temperature of the brake assembly and to use the determined temperature of the brake assembly to calibrate the calculation in step d).

[0109] Optionally, the control device is configured to determine the temperature of the brake assembly based on signals received from a temperature sensor and / or by monitoring the operating conditions of the brake assembly (for example, based on signals from a brake control system or other braking action sensors).

[0110] The control device is optionally configured to determine whether the temperature of the brake assembly is within a predetermined temperature range, and to execute step b) only when it is determined that the temperature of the brake assembly is within the predetermined temperature range.

[0111] Optionally, the control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by determining that a predetermined time has elapsed since the last braking operation.

[0112] Optionally, the control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by determining that the large vehicle has been started after a period of inactivity.

[0113] Optionally, the control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by measuring or estimating the temperature of the brake assembly based on a signal from a temperature sensor.

[0114] Optionally, the control device is configured to transmit signals corresponding to the thickness of the braking component calculated in step d) and / or the wear condition determined in step e) to an audible and / or visual indicator.

[0115] Optionally, the control device is configured to record in memory the thickness of the braking component calculated in step d) and / or the wear condition determined in step e).

[0116] Optionally, the control device is configured to transmit a signal to the wear monitoring system corresponding to the thickness of the braking component calculated in step d) and / or the wear condition determined in step e).

[0117] Further aspects of this disclosure provide a component kit comprising a control device, an ultrasonic emitter, and an ultrasonic sensor disclosed herein.

[0118] Further aspects of this disclosure relate to a control device that, when executed, provides a control device readable instruction configured to perform the method disclosed herein.

[0119] Further aspects of the present disclosure provide a method for measuring the temperature of a braking element in a brake assembly for a heavy vehicle. The method includes a) emitting a high-frequency sound wave through the braking element using an ultrasonic emitter and detecting the high-frequency sound wave with an ultrasonic sensor; b) measuring the time delay between the emission and detection of the high-frequency sound wave; and c) calculating the temperature of the braking element based on the time delay and the distance the high-frequency sound wave traveled between the ultrasonic sensor and the ultrasonic emitter.

[0120] It is known that the speed at which sound waves propagate through a medium varies with the temperature of the medium. In other words, the time required for sound waves to propagate a given distance through a medium varies with the temperature of the medium. Therefore, if high-frequency sound waves are emitted through a braking element (e.g., brake pads or rotors of a disc brake), and the distance traveled and the time delay between emission and detection (e.g., time of flight) are known, the temperature of the braking element can be calculated. This is useful for determining the braking state of brake assemblies for large vehicles and / or for calibrating calculations of thickness measurements.

[0121] Furthermore, in brake systems for large vehicles that have ultrasonic emitters / sensors for other reasons (e.g., for thickness measurement), this method allows for the calculation of temperature without the need for additional sensors (e.g., thermocouples embedded in the braking element).

[0122] Optionally, step c) includes c1) calculating the velocity of the high-frequency sound wave passing through the damping element by dividing the distance traveled by the high-frequency sound wave by the time delay, and c2) determining the temperature of the damping element based on the velocity of the high-frequency sound wave passing through the damping element.

[0123] Optionally, step c2) includes inputting the calculated high-frequency sound wave velocity into a mathematical function that defines the relationship between sound velocity and temperature for a damping element.

[0124] Optionally, the mathematical function is determined from experimental data, including sound velocity measurements obtained through the damping element material at multiple known temperatures.

[0125] By using such experimental data, a simple means is provided to determine an appropriate mathematical function without having to empirically derive the function based on the material properties of the braking element (which may be unknown).

[0126] The mathematical function is determined from experimental data using curve fitting techniques, at the discretion of the user.

[0127] By using curve fitting techniques, the number of experimental data points required to define a mathematical function can be reduced.

[0128] Optionally, the mathematical function is determined from experimental data using regression or interpolation.

[0129] Optionally, the distance traveled by the high-frequency sound wave is based on the thickness of the braking element, which is determined by a wear sensor assembly, and optionally, the wear sensor assembly includes an ultrasonic emitter and an ultrasonic sensor.

[0130] In this context, the term “thickness” is understood to mean the depth of the material forming the braking element. That is, if the braking element has an engagement surface that engages with a corresponding braking surface on different brake components, “thickness” is the dimension of the braking element perpendicular to the engagement surface. For example, in a disc brake assembly, the braking element may be a brake pad or a rotor, and “thickness” is the dimension of the braking element in the axial direction of the disc brake (i.e., parallel to the rotor’s axis of rotation). In a drum brake assembly, the braking element may be a brake shoe or a drum, and “thickness” is the dimension of the braking element in the radial direction of the drum brake (i.e., radial to the drum’s axis of rotation).

[0131] The wear sensor assembly determines the thickness of the braking element, which can make it easier to accurately measure the temperature of the braking element over time as it wears down.

[0132] Optionally, the braking element includes a support surface that supports a friction material having an engagement surface, and the braking element is configured to decelerate a large vehicle by engaging the engagement surface with the braking surface when actuated during braking, and optionally, the braking element is a brake pad for a disc brake or a brake shoe for a drum brake.

[0133] It is understood that the temperature of such braking elements rises when they are activated in braking action to decelerate a large vehicle. Therefore, measuring the temperature of such braking elements can be particularly useful (for example, to indicate the braking condition of a brake assembly).

[0134] Optionally, the method further includes measuring the temperature of a braking component having a braking surface, wherein the braking surface is configured to be engaged by a braking element to decelerate a heavy vehicle, and optionally, the braking component is the rotor of a disc brake or the drum of a drum brake.

[0135] It is understood that the temperature of such braking components rises when the braking element engages with the braking surface to decelerate a large vehicle. Therefore, measuring the temperature of such braking components can be particularly useful (for example, to indicate the braking state of the brake assembly).

[0136] In some embodiments, the braking components may be the braking elements described above. That is, in some embodiments, the temperature of the rotor or drum may be measured using the method described above without measuring the temperature of the corresponding brake pad or brake shoe.

[0137] Further aspects of the present disclosure provide a method for determining the braking state of a brake assembly for a heavy vehicle, the method comprising measuring the temperature of the braking elements of the brake assembly for a heavy vehicle using the method disclosed herein, and determining the braking state from the measured temperature.

[0138] Such methods can be useful in identifying faulty braking conditions, such as dragging brake pads or brake shoes. These methods can also be useful in providing the determined braking condition to the braking system (for example, to adjust the operation of the brake assembly).

[0139] Optionally, the braking element comprises a support surface for supporting a friction material having an engagement surface, and the braking element is configured to be actuated in a braking operation so that the engagement surface engages with a braking surface of a heavy vehicle brake assembly to decelerate the heavy vehicle, and the method includes determining that when the measured temperature is rising, the engagement surface is engaged with the braking surface to decelerate or limit the acceleration of the heavy vehicle.

[0140] Such methods can be useful in identifying faulty braking conditions, such as dragging brake pads or brake shoes. These methods can also be useful in providing the determined braking condition to the braking system (for example, to adjust the operation of the brake assembly).

[0141] Optionally, the method includes measuring the temperature of a first braking element using the method disclosed herein, measuring the temperature of a second braking element using the method disclosed herein, and determining that one of the first and second braking elements is in a drag state if the temperature of the first braking element is different from the temperature of the second braking element, optionally if the difference between the temperatures of the first and second braking elements exceeds a threshold temperature difference.

[0142] This method can be useful in identifying brake pads or brake shoes that are dragging.

[0143] Further aspects of the present disclosure provide a brake system for heavy-duty vehicles. The brake system for heavy-duty vehicles includes a brake assembly for heavy-duty vehicles comprising a braking element including a friction material having an engagement surface, wherein the braking element is configured to decelerate the heavy-duty vehicle by being actuated in a braking operation so that the engagement surface of the friction material engages with the braking surface of the braking element. The brake system for heavy-duty vehicles also includes an ultrasonic emitter, an ultrasonic sensor, and a control device. The control device is configured to a) instruct the ultrasonic emitter to emit high-frequency sound waves through the braking element and / or braking element so that they can be detected by the ultrasonic sensor, receive a signal from the ultrasonic sensor indicating the detected high-frequency sound waves, b) measure the time delay between the emission and detection of the high-frequency sound waves, and c) calculate the temperature of the braking element and / or braking element based on the time delay and the distance the high-frequency sound waves have traveled between the ultrasonic emitter and the ultrasonic sensor.

[0144] Optionally, the control device is configured to, in step c), c1) calculate the velocity of the high-frequency sound wave passing through the damping element and / or damping component by dividing the distance traveled by the high-frequency sound wave by a time delay, and c2) determine the temperature of the damping element and / or damping component based on the velocity of the high-frequency sound wave passing through the damping element and / or damping component, optionally by inputting the calculated velocity of the high-frequency sound wave into a mathematical function that defines the relationship between the speed of sound and temperature for the damping element and / or damping component, optionally by determining the mathematical function from experimental data including speed of sound measurements obtained through the material of the damping element and / or damping component at a plurality of known temperatures, optionally by determining the mathematical function from experimental data using curve fitting techniques, optionally by determining the mathematical function from experimental data using regression or interpolation.

[0145] Optionally, the ultrasonic emitter and ultrasonic sensor are both positioned on opposite sides of the engagement surface in the friction material of the braking element, so that the high-frequency sound waves emitted by the ultrasonic emitter are reflected at the engagement surface and subsequently detected by the ultrasonic sensor. Alternatively, the ultrasonic emitter and ultrasonic sensor are positioned on opposite sides of the braking component, so that the high-frequency sound waves emitted by the ultrasonic emitter pass through the braking component and reach the ultrasonic sensor.

[0146] Optionally, the control device is further configured to determine the braking state of the brake assembly for the heavy vehicle based on the temperature calculated in step c).

[0147] Such systems can be useful in identifying faulty braking conditions, such as dragging brake pads or brake shoes. They can also be useful in providing the determined braking condition to a braking control system (for example, to adjust the operation of the brake assembly).

[0148] Optionally, the control device is configured to determine in step d) that when the temperature calculated in step c) is rising, the engaging surface of the braking element is engaged with the braking surface of the braking component, thereby decelerating or limiting the acceleration of the large vehicle.

[0149] Such systems can be useful in identifying faulty braking conditions, such as dragging brake pads or brake shoes. They can also be useful in providing the determined braking condition to a braking control system (for example, to adjust the operation of the brake assembly).

[0150] Optionally, the control device is configured to measure the temperature of a first braking element of a heavy vehicle brake assembly and the temperature of a second braking element of a heavy vehicle brake assembly in step d), and to determine that one of the first and second braking elements is in a dragging state if the temperature of the first braking element is different from the temperature of the second braking element, and optionally, this is the case when the temperature difference between the first and second braking elements exceeds a threshold temperature difference.

[0151] Further aspects of the present disclosure provide a disc brake including a brake system for heavy vehicles disclosed herein, wherein the braking components are a rotor rotatably fixed to a vehicle wheel, and each braking element or braking element is a brake pad having a friction material, optionally the brake pad having a back plate and the friction material being fixed to the back plate.

[0152] Such disc brakes benefit from the advantages of the large vehicle braking systems described above.

[0153] Further aspects of the present disclosure provide a drum brake including a brake system for heavy vehicles disclosed herein, wherein the braking components are a rotor rotatably fixed to a vehicle wheel, and each braking element or braking element is a brake pad having a friction material, optionally the brake pad having a back plate, and the friction material being fixed to the back plate.

[0154] Such drum brakes benefit from the advantages of the large vehicle braking systems described above.

[0155] Further aspects of the present disclosure provide a control device for a vehicle brake system. The control device is configured to a) instruct an ultrasonic emitter to emit high-frequency sound waves through the braking elements and / or braking components of a heavy vehicle brake system, to be detected by an ultrasonic sensor, to receive a signal from the ultrasonic sensor indicating the detected high-frequency sound waves, b) measure the time delay between the emission and detection of the high-frequency sound waves, and c) calculate the temperature of the braking elements and / or braking components based on the time delay and the distance the high-frequency sound waves have traveled between the ultrasonic emitter and the ultrasonic sensor.

[0156] Optionally, the control device is configured to, in step c), c1) calculate the velocity of the high-frequency sound wave passing through the damping element and / or damping component by dividing the distance traveled by the high-frequency sound wave by a time delay, and c2) determine the temperature of the damping element and / or damping component based on the velocity of the high-frequency sound wave passing through the damping element and / or damping component, optionally by inputting the calculated velocity of the high-frequency sound wave into a mathematical function that defines the relationship between the speed of sound and temperature for the damping element and / or damping component, optionally by determining the mathematical function from experimental data including speed of sound measurements obtained through the material of the damping element and / or damping component at a plurality of known temperatures, optionally by determining the mathematical function from experimental data using curve fitting techniques, optionally by determining the mathematical function from experimental data using regression or interpolation.

[0157] Optionally, the control device is further configured to determine the braking state of the heavy vehicle brake assembly based on the temperature calculated in step c).

[0158] Such control devices may be useful for identifying faulty braking conditions, such as dragging brake pads or brake shoes. Such devices may also be useful for providing the determined braking condition to a braking control system (for example, to adjust the operation of the brake assembly).

[0159] Optionally, the control device is configured to determine in step d) that when the temperature calculated in step c) is rising, the engaging surface of the braking element is engaged with the braking surface of the braking component, thereby decelerating or limiting the acceleration of the large vehicle.

[0160] Such control devices may be useful for identifying faulty braking conditions, such as dragging brake pads or brake shoes. Such devices may also be useful for providing the determined braking condition to a braking control system (for example, to adjust the operation of the brake assembly).

[0161] Optionally, the control device is configured to measure the temperature of a first braking element of a heavy vehicle brake assembly and the temperature of a second braking element of a heavy vehicle brake assembly in step d), and to determine that one of the first and second braking elements is in a dragging state if the temperature of the first braking element is different from the temperature of the second braking element, and optionally, this is the case when the temperature difference between the first and second braking elements exceeds a threshold temperature difference.

[0162] Further aspects of this disclosure provide a component kit having a control device, an ultrasonic emitter, and an ultrasonic sensor disclosed herein. The control device, ultrasonic emitter, and ultrasonic sensor may be housed in a single ultrasonic sensor assembly. Alternatively, the control device may be positioned at a distance from the ultrasonic emitter and ultrasonic sensor. For example, the control device may be part of a vehicle control system.

[0163] Further aspects of this disclosure provide instructions that are readable by a control device configured to perform the methods disclosed herein when executed by the control device.

[0164] Within the scope of this application, the various aspects, embodiments, examples, and alternative configurations described in the paragraphs, claims, and / or the following description and drawings, and in particular their individual features, are expressly intended to be adopted independently or in any combination. That is, all embodiments and / or features of any embodiment can be combined in any way and / or combination, provided that such features do not result in inconsistencies. The applicant reserves the right to modify any claim initially filed, or to file any new claim accordingly, including the right to amend any claim initially filed to incorporate any feature dependent on and / or of any other claim, even if not initially so. [Brief explanation of the drawing]

[0165] Embodiments of the present invention will be described below with reference to the accompanying drawings. [Figure 1] This is a perspective view of a disc brake for large vehicles. [Figure 2] This is a heavy-duty vehicle braking system that includes a control device and a large vehicle disc brake shown in Figure 1 in a cross-section along Plane 3-3. [Figure 3] Figure 2 is a schematic diagram of the control device. [Figure 4] Figures 1 and 2 are enlarged views of the brake pads and rotors of the large vehicle disc brakes shown. [Figure 5A] Figure 2 is a perspective view of the ultrasonic device in a large vehicle braking system. [Figure 5B] This is a cross-sectional view of the ultrasonic device shown in Figure 5A, passing through plane 5B-5B. [Figure 6] This is a cross-sectional view of a drum brake for large vehicles. [Figure 7] This is a block diagram of a method for detecting wear in brake assemblies for large vehicles. [Figure 8] This is a block diagram of a method for determining the braking state of a brake assembly for large vehicles. [Figure 9]This is a block diagram of a method for measuring the temperature of braking elements in a brake assembly for large vehicles. [Figure 10] This is a block diagram of a method for determining the braking state of a brake assembly for large vehicles. [Figure 11] This is a block diagram of a further method for determining the braking state of a brake assembly for a large vehicle. [Figure 12] This graph shows the time-of-flight measurements of high-frequency sound waves passing through a brake pad, obtained at different temperatures. [Figure 13] This is a graph of an example of a mathematical function used to determine the temperature of a braking element from the calculated speed of sound. [Modes for carrying out the invention]

[0166] Figures 1 and 2 show a brake assembly for a large vehicle, which is a disc brake 2 in this embodiment. The function of such a disc brake 2 is well known and will not be described in detail, but briefly, the brake carrier positions the braking elements 6 and 8 so as to face the first and second braking surfaces 11A and 11B of the braking component. In this case, the braking component is a rotor 10 that is rotatably fixed to the vehicle wheel, the first and second braking surfaces 11A and 11B are on both sides of the rotor 10, and the braking elements are the brake pad 6 on the inside in the vehicle width direction and the brake pad 8 on the outside in the vehicle width direction. The actuator 4 engages with the brake pad 6 on the inside in the vehicle width direction and presses it toward the rotor 10. Due to the reaction force, the caliper slides against the brake carrier and presses the brake pad 8 on the outside in the vehicle width direction toward the rotor 10. The brake pad 6 on the inside in the vehicle width direction and the brake pad 8 on the outside in the vehicle width direction each have a back plate 12 that defines a support surface for positioning and supporting the friction material 14. The friction material 14 has an engagement surface 16 positioned opposite the rotor 10. As a result, when the brake pad 6 on the inside in the vehicle width direction and the brake pad 8 on the outside in the vehicle width direction move toward the rotor 10 during braking, the engagement surfaces 16 of the brake pad 6 on the inside in the vehicle width direction and the brake pad 8 on the outside in the vehicle width direction engage with the braking surfaces 11A and 11B on both sides of the rotor 10, thereby decelerating the vehicle.

[0167] Over time, the friction material 14 of the brake pads 6 on the inside in the vehicle width direction and the brake pads 8 on the outside in the vehicle width direction wear down. Similarly, the rotor 10 also wears down over time. That is, the thickness of the rotor 10 (measured, for example, in a direction parallel to the rotation axis R of the rotor 10) decreases over time. However, since the rotor 10 does not wear down at the same rate as the friction material 14, it is useful to know exactly when the rotor 10 should be replaced (for example, when the thickness of the rotor 10 falls below a threshold thickness).

[0168] In the embodiment shown in Figure 2, as will be described in more detail below, the heavy-duty vehicle disc brake 2 is part of a heavy-duty vehicle braking system 100, which can be used to measure the thickness of the rotor 10 and the temperature of the brake pads 6, 8 and / or the rotor 10. The heavy-duty vehicle braking system 100 also includes a first ultrasonic device 102A having an ultrasonic emitter 104 located on the first side of the rotor 10. The first ultrasonic device 102A is movable between an unengaged state (shown in Figure 2) in which the first ultrasonic device 102A is not in contact with the first braking surface 11A of the rotor 10 and an engaged state (not shown) in which the ultrasonic device 102 is in contact with the first braking surface 11A of the rotor 10.

[0169] When the first ultrasonic device 102A is engaged, the operating clearance G between the first damping surface 11A and the first ultrasonic device 102A (best shown in Figure 4) is understood to be zero. In other words, there is no gap or air gap between the first ultrasonic device 102A and the first damping surface 11A. Conversely, when the first ultrasonic device 102A is disengaged, the operating clearance G between the first damping surface 11A and the first ultrasonic device 102A is understood to be greater than zero, as shown in Figure 4. In other words, there is a gap or air gap between the first ultrasonic device 102A and the first damping surface 11A. For example, when the first ultrasonic device 102A is in a disengaged state, the operating clearance / air gap G between the first ultrasonic device 102A and the first damping surface 11A may be a distance greater than 0.5 mm (for example, greater than 1 mm, greater than 2 mm, greater than 4 mm, greater than 6 mm, greater than 8 mm, greater than 10 mm, greater than 15 mm, greater than 20 mm).

[0170] As best shown in Figure 4, the first braking surface 11A and the first ultrasonic device 102A form complementary engagement surfaces 19 configured to contact each other. In the illustrated disc brake embodiment, the complementary engagement surfaces 19 are planar. In other embodiments, such as the drum brake embodiment, the complementary engagement surfaces 19 are curved surfaces (e.g., the convex surface of the first ultrasonic device 102A to engage with the complementary concave surface of the first braking surface 11A). When the first ultrasonic device 102A is in an unengaged state (as shown in Figures 2 and 4), it is understood that the first ultrasonic device 102A and the first braking surface 11A are separated from each other by a gap or air gap between the complementary engagement surfaces 19. Conversely, when the first ultrasonic device 102A is engaged, there is no gap or air gap between the complementary engagement surfaces 19 (i.e., the complementary engagement surfaces 19 are in contact with each other).

[0171] Furthermore, as shown in Figure 2, the heavy vehicle braking system 100 has an ultrasonic sensor 106, which in the illustrated embodiment is part of a second ultrasonic device 102B located on the second side of the rotor 10, opposite the first side. The second ultrasonic device 102B is movable between an unengaged state (as shown in Figure 2) in which the second ultrasonic device 102B is not in contact with the second braking surface 11B of the rotor 10, and an engaged state (not shown) in which the second ultrasonic device 102B is in contact with the second braking surface 11B of the rotor 10. Similar to the operating clearance G shown in Figure 4, the operating clearance / air gap G between the second ultrasonic device 102B and the second braking surface 11B is greater than zero when the second ultrasonic device 102B is in the unengaged state and zero when the second ultrasonic device 102B is in the engaged state. For example, when the second ultrasonic device 102B is in an unengaged state, the operating clearance / air gap G between the second ultrasonic device 102B and the second damping surface 11B may be a distance greater than 0.5 mm (for example, greater than 1 mm, greater than 2 mm, greater than 4 mm, greater than 6 mm, greater than 8 mm, greater than 10 mm, greater than 15 mm, greater than 20 mm).

[0172] The first and second ultrasonic devices 102A and 102B are arranged such that the ultrasonic sensor 106 of the second ultrasonic device 102B is located in the path of the high-frequency sound waves emitted from the ultrasonic emitter 104 of the first ultrasonic device 102A (for example, by having the first and second ultrasonic devices 102A and 102B facing each other and aligned coaxially). In this way, the first and second ultrasonic devices 102A and 102B may be used in a "throw-and-catch" configuration, in which the high-frequency sound waves transmitted from the ultrasonic emitter 104 of the first ultrasonic device 102A are transmitted directly to the ultrasonic sensor 106 of the second ultrasonic device 102B.

[0173] In an alternative embodiment, the first ultrasonic device 102A comprises an ultrasonic emitter 104 and an ultrasonic sensor 106. In such an embodiment, it is understood that high-frequency sound waves emitted from the ultrasonic emitter 104 are reflected at the boundary between different densities (for example, the boundary between the distal side of the rotor 10 opposite to the first ultrasonic device 102A and the air gap or the opposing brake pad 8). The reflected high-frequency sound waves may then be detected by the ultrasonic sensor 106 of the first ultrasonic device. In such an embodiment, it is understood that the second ultrasonic device 102B is optional. Such an alternative configuration can be used, for example, in a drum brake for a heavy vehicle where the braking component is a drum that is rotatably fixed relative to the vehicle wheel, the braking surface is the inner surface of the drum, and the braking element is a brake shoe having a brake lining of friction material. In such an embodiment, it is understood that it is particularly beneficial to have one ultrasonic device 102A configured to emit and detect high-frequency sound waves from one side of the drum, since the drum engages with the brake shoe from only one side.

[0174] In some embodiments, each of the first and second ultrasonic devices 102A, 102B includes both an ultrasonic emitter 104 and an ultrasonic sensor 106. Thus, the first and second ultrasonic devices 102A, 102B can also be used independently of each other (for example, to measure wear of the braking elements 6, 8, as disclosed in European Patent Application EP23179290.4, which is incorporated herein by reference).

[0175] Furthermore, the heavy-duty vehicle braking system 100 includes a control device 108. In some embodiments, the control device 108 is mounted on the heavy-duty vehicle disc brake 2, so that the heavy-duty vehicle braking system 100 can be provided as a single unit. For example, the control device 108 may be mounted on the brake carrier or any other suitable surface of the disc brake 2. In other embodiments, the control device 108 is part of a main vehicle control unit (e.g., a central control unit that controls the brake assembly and / or other functions of the vehicle).

[0176] In some embodiments, the control device 108 is configured to determine when the ultrasonic devices 102A and 102B are engaged. That is, the control device 108 is configured to determine when there is no air gap or void between the ultrasonic emitter 104 of the first ultrasonic device 102A and the ultrasonic sensor 106 of the second ultrasonic device 102B. This is important for obtaining accurate readings because high-frequency sound waves do not reliably propagate through air gaps / voids.

[0177] When it is determined that the ultrasonic devices 102A and 102B are engaged, the control device 108 is configured to instruct the ultrasonic emitter 104 of the first ultrasonic device 102A to emit high-frequency sound waves through the rotor 10, and to detect the high-frequency sound waves by the ultrasonic sensor 106 of the second ultrasonic device 102B, and to receive a signal from the ultrasonic sensor 106 indicating the detected high-frequency sound waves. In embodiments in which the first ultrasonic device 102A has an ultrasonic sensor 106 together with the ultrasonic emitter 104 (for example, an embodiment in which the second ultrasonic device 102B is omitted), it is understood that the control device 108 is only configured to determine that the first ultrasonic device 102A is engaged before commanding the ultrasonic emitter 104 to emit high-frequency sound waves.

[0178] In some embodiments, the control device 108 is configured to measure the time delay between the emission and detection of high-frequency sound waves and to calculate the thickness of the rotor 10 based on the time delay. The thickness of the rotor 10 may be calculated using an algorithm based on a known formula. For example, the thickness calculation may be proportional to the product of the velocity of the high-frequency sound waves and the measured time delay. Other factors, such as the distance between the ultrasonic emitter 104 and the engagement surface 19 of the first ultrasonic device 102A, and the distance between the ultrasonic sensor 106 and the engagement surface 19 of the second ultrasonic device 102B, may be taken into consideration by the algorithm.

[0179] In some embodiments, the control device 108 is configured to determine the temperature of the disc brake 2 (e.g., the temperature of the brake carrier, brake pads 6, 8, rotor 10 and / or any other components of the disc brake 2) and to calibrate the thickness calculation using the determined temperature. Since the output of the ultrasonic sensor 106 may vary with temperature, it is understood that calibrating the thickness calculation using the determined temperature allows for accurate measurement of the rotor 10's thickness.

[0180] The control device 108 may be configured to determine the temperature of the disc brake 2 based on a signal received from a temperature sensor 124 (for example, a temperature sensor 124 that is part of the heavy vehicle braking system 100). Alternatively, the control device 108 may be configured to determine the temperature of the disc brake 2 by monitoring the operating conditions of the disc brake 2. For example, the temperature can be estimated based on the duration of the braking operation, using the principle that the temperature rises while a heavy vehicle is decelerated using the disc brake 2. The control device 108 may monitor the operating conditions of the disc brake using a signal received from the brake control system 110 or other braking operation sensors. Alternatively, as will be described in more detail below, the control device 108 may be configured to determine the temperature of the disc brake 2 using an ultrasonic emitter 104 and a sensor 106.

[0181] In some embodiments, the control device 108 determines whether the temperature of the disc brake 2 is within a predetermined temperature range, and only when it is determined that the temperature of the disc brake 2 is within the predetermined temperature range, it commands the ultrasonic emitter 104 to emit high-frequency sound waves through the rotor 10, which are then detected by the ultrasonic sensor 106. It is understood that the output from the ultrasonic sensor 106 may change with temperature. Therefore, by determining whether the temperature of the disc brake 2 is within a predetermined temperature range (for example, the temperature range for which the calculation of the rotor thickness is calibrated), and performing emission / detection / thickness calculation only within this temperature range, the thickness of the rotor 10 can be accurately measured.

[0182] The control device 108 may be configured to determine whether the temperature of the disc brake 2 is within a predetermined temperature range by determining that a predetermined time has elapsed since the last braking operation, determining that the heavy vehicle has been started after the stopping period, and / or by measuring or estimating the temperature of the disc brake 2 based on a signal from the temperature sensor 124 (for example, the temperature sensor 124 which is part of the heavy vehicle braking system 100).

[0183] The control device 108 may be configured to record the calculated thickness of the rotor 10 in a memory 116 (for example, a memory 116 which is part of the heavy vehicle braking system 100 or part of an external system). This allows tracking of the thickness trend over time. The memory 116 may store instructions that are readable by a control device, which is configured to perform one or more steps of the control device described herein when executed by the control device 108.

[0184] The control device 108 may be configured to transmit a signal corresponding to the calculated rotor thickness 10 to an audible and / or visual indicator 118 (for example, an audible and / or visual indicator 118 which is part of the heavy vehicle braking system 100 or part of an external system). In some embodiments, the indicator 118 may be a warning light and / or alarm on the dashboard of the heavy vehicle. In some embodiments, the indicator 118 may be a warning light and / or alarm on the exterior of the heavy vehicle's body. Such an indicator 118 allows the driver or maintenance technician to determine the thickness of the rotor 10 and take appropriate action as needed.

[0185] The control device 108 may be configured to transmit a signal corresponding to the calculated rotor thickness 10 to a monitoring system 120 (e.g., a thickness monitoring system and / or a wear monitoring system). The monitoring system 120 may be part of the heavy vehicle braking system 100 or at least part of an external system. For example, the monitoring system 120 may be a central system for monitoring the thickness of each rotor 10 of each vehicle in a group of heavy vehicles. The signal may be transmitted to the monitoring system 120 via a transmitter 122 (e.g., a wireless transmitter).

[0186] In some embodiments, the control device 108 is further configured to determine the wear status of the rotor 10 based on changes in the thickness of the rotor 10 over time. That is, the control device 108 automatically determines the wear status (e.g., "worn and needs to be replaced soon," or "partially worn but does not need to be replaced yet") without the user having to manually monitor the thickness of the rotor 10. In such embodiments, the control device 108 may determine that the rotor 10 is worn and needs to be replaced if the calculated thickness of the rotor 10 falls below a thickness threshold.

[0187] In some embodiments, the control device 108 is configured to determine the wear status of the rotor 10 by comparing the calculated thickness of the rotor 10 with a reference thickness stored in the memory 116. The memory 116 may be part of the heavy vehicle braking system 100 or part of a separate system (e.g., an independent thickness monitoring system). The reference thickness may be the initial thickness of the rotor and / or the thickness of one or more rotors previously calculated. For example, if the difference between the calculated thickness and the reference thickness exceeds a threshold delta value, it may be determined that the rotor 10 is worn and needs to be replaced.

[0188] In some embodiments, the control device 108 is configured to determine the wear state of the rotor 10 based on the difference between the calculated thickness of the rotor 10 and the calculated thickness of another rotor on the same vehicle. For example, the control device 108 may determine that the rotor 10 is prematurely worn / has worn out if the calculated thickness of the rotor is less than a threshold value compared to the calculated thickness of another rotor on the same vehicle.

[0189] The control device 108 may be configured to record the determined wear state of the rotor 10 in a memory 116 (for example, a memory 116 which is part of the heavy vehicle braking system 100 or part of an external system). This makes it possible to track the wear trend over time.

[0190] The control device 108 may be configured to transmit a signal corresponding to the determined wear condition of the rotor 10 to an audible and / or visual indicator 118 (for example, an audible and / or visual indicator 118 which is part of the heavy vehicle braking system 100 or part of an external system). In some embodiments, the indicator 118 may be a warning light and / or alarm on the dashboard of the heavy vehicle. In some embodiments, the indicator 118 may be a warning light and / or alarm on the exterior of the body of the heavy vehicle. Such an indicator 118 allows the driver or maintenance technician to understand the wear condition of the rotor 10 and take appropriate action as needed.

[0191] The control device 108 may be configured to transmit a signal corresponding to the determined wear condition of the rotor 10 to a monitoring system 120 (e.g., a wear monitoring system). The monitoring system 120 may be part of the heavy vehicle braking system 100, or at least part of an external system. For example, the monitoring system 120 may be a central system for monitoring the wear condition of each rotor 10 of each vehicle in a group of heavy vehicles. The signal may be transmitted to the monitoring system 120 via a transmitter 122 (e.g., a wireless transmitter).

[0192] In other embodiments, the control device 108 is not configured to determine the wear condition of the rotor 10. Instead, the wear condition may be determined manually or by an external system (e.g., an external monitoring system 120) based on the calculated thickness of the rotor 10.

[0193] In the illustrated embodiment, the first and second ultrasonic devices 102A and 102B (and the corresponding ultrasonic emitters 104 and sensors 106) are fixed relative to (for example, firmly fixed to) the corresponding brake pads 6 and 8, respectively. In this way, the first and second ultrasonic devices 102A and 102B can be moved toward the corresponding braking surfaces 11A and 11B, respectively, during braking, thereby facilitating measurement of the rotor thickness 10.

[0194] In the illustrated embodiment, the first and second ultrasonic devices 102A and 102B (and the corresponding ultrasonic emitters 104 and sensors 106) are fixed directly to the corresponding brake pads 6 and 8 by being located in a central region spaced apart from the circumferential and radial edges of the brake pads 6 and 8. In this embodiment, this central region has a recess 18 that extends through the friction material 14. In this embodiment, the recess 18 extends axially, i.e., parallel to the central axis of rotation of the rotor 10, through the entire depth of the friction material. In this embodiment, the recess 18 has a circular cross-section corresponding to the cylindrical ultrasonic devices 102A and 102B, but it can have any suitable cross-sectional shape. Since the recess 18 has been used to position known pad wear warning indicator devices in conventional brake pads, the ultrasonic devices 102A and 102B can be retrofitted to existing brake pads 6 and 8 at this location.

[0195] In an embodiment in which the first and second ultrasonic devices 102A and 102B are fixed relative to the corresponding brake pads 6 and 8, respectively, it is understood that the control device 108 may determine that the ultrasonic devices 102A and 102B are engaged by determining that the engaging surfaces 16 of the friction material 14 of the brake pads 6 and 8 are in contact with the corresponding braking surfaces 11A and 11B of the rotor 10, respectively.

[0196] In some embodiments, the control device 108 may determine that the engagement surfaces 16 of the friction material 14 of the brake pads 6 and 8 are in contact with the corresponding braking surfaces 11A and 11B of the rotor 10 by transmitting a command to the brake control system 110 (for example, a separate brake system) to activate the brake pads 6 and 8 and engage them with the braking surfaces 11A and 11B. For example, the control device 108 may transmit a command to the brake control system 110 when a large vehicle is started (usually when the brakes are applied).

[0197] In some embodiments, the control device 108 may determine, by receiving signals from the brake pedal sensor 112 and / or the separate brake system 110, that the engagement surfaces 16 of the friction material 14 of the brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B of the rotor 10.

[0198] In some embodiments, the control device 108 may determine that the engagement surfaces 16 of the friction material 14 of the brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B of the rotor 10 by measuring the pressure in the hydraulic or pneumatic brake line connected to the actuator 4 (for example, using a pressure sensor 114 which is part of a heavy vehicle braking system 100 or part of an external system such as a separate brake system 110).

[0199] In some embodiments, the control device 108 may determine that the engagement surfaces 16 of the friction material 14 of the brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B of the rotor 10 by identifying changes in high-frequency sound waves detected by the ultrasonic sensor 106. For example, when the first and second ultrasonic devices 102A, 102B are moved into an engaged state to close the air gap between the braking surfaces 11A, 11B and the first and second ultrasonic devices 102A, 102B, the detected high-frequency sound waves may change abruptly.

[0200] In some embodiments, the control device 108 may determine that the engagement surfaces 16 of the friction material 14 of the brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B of the rotor 10 by measuring the current in an electrical circuit connected to the actuator 4 (for example, using any suitable current sensing sensor or device 115).

[0201] It is understood that the control device 108 may use a combination of the above methods (for example, at least two independent methods to avoid "false positives" in the event of a single sensor failure) to determine whether the engagement surfaces 16 of the friction material 14 of the brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B of the rotor 10.

[0202] In some embodiments, the ultrasonic devices 102A, 102B and their components are not fixed to the brake pads 6, 8. The ultrasonic devices 102A, 102B can be provided in any suitable position as long as they are movable between engaged and disengaged states. For example, the first and / or second ultrasonic devices 102A, 102B may be part of a mobile probe used to manually measure the thickness of the rotor 10 by bringing the probe into contact with the rotor 10 and engaging the corresponding ultrasonic devices 102A, 102B, respectively. In such embodiments, it is understood that the control device 108 does not need to be configured to determine whether the first and / or second ultrasonic devices 102A, 102B are engaged before commanding the ultrasonic emitter 104 to emit high-frequency sound waves through the rotor 10. Instead, the probe operator may determine the engaged state manually (e.g., by visual or tactile feedback) and then activate a user input (e.g., a button) to begin calculating the thickness. Furthermore, the control device 108 may be configured to perform the same steps as receiving a signal from the user input: instructing the ultrasonic emitter 104 to emit high-frequency sound waves through the rotor 10; receiving a signal from the ultrasonic sensor 106 indicating the detected high-frequency sound waves; measuring the time delay between the emission and detection of the high-frequency sound waves; and calculating the thickness of the rotor 10 based on the time delay.

[0203] It is understood that when the actuator 4 is activated, the friction material 14 of the brake pads 6 and 8 engages with the braking surfaces 11A and 11B of the rotor 10, thereby decelerating the vehicle, and that the frictional force between the friction material 14 and the braking surfaces 11A and 11B causes the temperatures of the brake pads 6 and 8 and the rotor 10 to rise. It is also understood that if the temperature change of the brake pads 6 and 8 and / or the rotor 10 can be measured, the condition of the disc brake 2 (e.g., a dragging brake pad) can be determined. It may also be useful to determine the temperature of the brake pads 6 and 8 and / or the rotor 10 for other purposes (e.g., to calibrate ultrasonic thickness measurements using the methods / apparatus disclosed in European Patent Applications EP23179290.4 and EP23188733.2, which are described herein and incorporated herein by reference).

[0204] As described above, in the illustrated embodiment, the first ultrasonic device 102A is fixed to the brake pad 6 on the inner side in the vehicle width direction and has an ultrasonic emitter 104 and an ultrasonic sensor 106 located in the same place, which are arranged so that high-frequency sound waves emitted from the ultrasonic emitter 104 pass through the brake pad 6 on the inner side in the vehicle width direction and are reflected (for example, at the engagement surface 16 of the brake pad 6 on the inner side in the vehicle width direction) and detected by the ultrasonic sensor 106.

[0205] In some embodiments, the control device 108 is configured to command the ultrasonic emitter 104 of the first ultrasonic device 102A to emit high-frequency sound waves through the brake pad 6 on the inside in the vehicle width direction, and to receive a signal indicating the detected high-frequency sound waves (i.e., reflected high-frequency sound waves) from the ultrasonic sensor 106 of the first ultrasonic device 102A.

[0206] The control device 108 may be configured to measure the time delay between the transmission and detection of high-frequency sound waves.

[0207] Furthermore, the control device 108 may be configured to calculate the temperature of the brake pad 6 on the inside in the vehicle width direction based on a time delay and the distance traveled by the high-frequency sound wave between the ultrasonic emitter 104 and the ultrasonic sensor 106 (i.e., twice the distance between the ultrasonic emitter 104 and the ultrasonic sensor 106, which are located at the same location as the engagement surface 16 of the brake pad 6).

[0208] In some embodiments, the control device 108 is configured to calculate the velocity of the high-frequency sound wave passing through the brake pad 6 on the inside in the vehicle width direction by dividing the distance traveled by the high-frequency sound wave by the time delay. That is, the control device 108 is configured to execute the following equation, where v s Δt is the speed of the high-frequency sound wave, d is the distance the high-frequency sound wave has traveled, and Δt is the time delay between the emission and detection of the high-frequency sound wave. v s =d / Δt

[0209] Furthermore, the control device 108 may be configured to determine the temperature of the brake pad 6 on the inner side in the vehicle width direction based on the velocity of the high-frequency sound waves passing through the brake pad 6 on the inner side in the vehicle width direction. For example, the control device 108 may be configured to input the calculated velocity of the high-frequency sound waves into a mathematical function that defines the relationship between the speed of sound and temperature for the brake pad 6 on the inner side in the vehicle width direction. That is, the control device 108 is configured to execute the following equation, where T is the temperature of the brake pad 6 on the inner side in the vehicle width direction and f() is a mathematical function. T=f(v s )

[0210] The mathematical function may be determined from experimental data including measurements of the speed of sound obtained through the material of the brake pad 6 on the inner side in the vehicle width direction at several known temperatures. For example, the mathematical function may be determined from experimental data using curve fitting techniques such as regression or interpolation. Such techniques are publicly known and will not be described in detail.

[0211] Similar in configuration to the brake pad 6 on the inner side in the vehicle width direction, the brake pad 8 on the outer side in the vehicle width direction has a second ultrasonic device 102B. The second ultrasonic device 102B has an ultrasonic emitter 104 and an ultrasonic sensor 106 located in the same place, which are positioned so that high-frequency sound waves emitted from the ultrasonic emitter 104 of the second ultrasonic device 102B pass through the brake pad 8 on the outer side in the vehicle width direction and are reflected (for example, at the engagement surface 16 of the brake pad 8 on the outer side in the vehicle width direction) and detected by the ultrasonic sensor 106 of the second ultrasonic device 102B.

[0212] The control device 108 may be configured to calculate the temperature of the brake pad 8 on the outside in the vehicle width direction in the same manner as the calculation of the temperature of the brake pad 6 on the inside in the vehicle width direction described above. For example, the control device 108 may be configured to command the ultrasonic emitter 104 of the second ultrasonic device 102B to emit high-frequency sound waves and to receive a signal indicating the detected high-frequency sound waves from the ultrasonic sensor 106 of the second ultrasonic device 102B. Subsequently, the control device 108 can calculate the temperature of the brake pad 8 on the outside in the vehicle width direction based on the time delay between the emission and detection of the high-frequency sound waves and the distance the high-frequency sound waves have traveled (i.e., twice the distance between the ultrasonic emitter 104 and sensor 106 located at the same location on the second ultrasonic device 102B and the engagement surface 16 of the brake pad 8 on the outside in the vehicle width direction).

[0213] With the illustrated configuration of the first and second ultrasonic devices 102A and 102B located on both sides of the rotor 10, (for example, during braking operations when brake pads 6 and 8 are engaged with the rotor 10 and there is no air gap between the ultrasonic devices 102A and 102B and the rotor 10) high-frequency sound waves emitted from the ultrasonic emitter of one ultrasonic device 102A or 102B can pass through the rotor 10 and be detected by the ultrasonic sensor 106 of the other ultrasonic device 102A or 102B.

[0214] In some embodiments, the control device 108 is configured to calculate the temperature of the rotor 10 in a manner similar to that used for calculating the brake pad temperature. For example, the control device 108 may be configured to command the ultrasonic emitter 104 of one ultrasonic device 102A, 102B to emit high-frequency sound waves and to receive a signal indicating the detected high-frequency sound waves from the ultrasonic sensor 106 of the other ultrasonic device 102A, 102B. The control device 108 may then calculate the temperature of the rotor 10 based on the time delay between the emission and detection of the high-frequency sound waves and the distance traveled by the high-frequency sound waves (i.e., the sum of the distances traveled by each brake pad 6, 8 and the rotor 10).

[0215] In some embodiments, the control device 108 may be configured to determine, before calculating the temperature of the rotor 10, whether the ultrasonic devices 102A and 102B are engaged with the rotor 10 (for example, using the technique outlined in European Patent Application EP23188733.2, which is incorporated herein by reference). For example, the control device 108 can determine whether the ultrasonic devices 102A and 102B are engaged with the rotor 10 using the method described above.

[0216] As shown in Figure 3, the control device 108 may be configured to record the calculated temperatures of the brake pads 6, 8 and / or rotor 10 in a memory 116 (for example, a memory 116 which is part of the heavy vehicle brake system 100 or part of an external system). This allows tracking of temperature trends over time. The memory 116 may store instructions that are readable by a control device configured to perform one or more steps of the control device described herein when executed by the control device 108.

[0217] The control device 108 may be configured to transmit a signal corresponding to the calculated temperatures of the brake pads 6, 8 and / or rotor 10 to an audible and / or visual indicator 118 (for example, an audible and / or visual indicator 118 which is part of the heavy vehicle brake system 100 or part of an external system). In some embodiments, the indicator 118 may be a warning light and / or alarm on the dashboard of the heavy vehicle. Such an indicator 118 allows the driver to know the temperature of the brake pads 6, 8 and / or rotor 10 (for example, when the brake pads 6, 8 and / or rotor 10 are overheating) and take appropriate action if necessary.

[0218] The control device 108 may be configured to transmit signals to the monitoring system 120 corresponding to the calculated temperatures of the brake pads 6, 8 and / or rotors 10. The monitoring system 120 may be part of the heavy vehicle brake system 100, or at least part of an external system. For example, the monitoring system 120 may be a central system for monitoring the temperature of each brake pad 6, 8 and / or rotor 10 of each vehicle in a group of heavy vehicles. The signals may be transmitted to the monitoring system 120 via a transmitter 122 (e.g., a wireless transmitter).

[0219] In some embodiments, the control device 108 is further configured to determine the braking state of the heavy vehicle disc brake 2 based on the temperature of the brake pads 6, 8 and / or the rotor 10. For example, the control device 108 may be configured to determine that when the temperature of the brake pads 6, 8 and / or the rotor 10 is rising, the engagement surfaces 16 of the brake pads 6, 8 are engaged with the braking surfaces 11A, 11B of the rotor 10, causing the heavy vehicle to decelerate. This may be used in the feedback loop of the actuator 4 or transmitted to an audible / visual indicator 118 to inform the driver when the brakes are being used.

[0220] In some embodiments, the control device 108 is configured to determine that one of the inner and outer brake pads 6, 8 is in a dragging state (i.e., undesirably engaged with the rotor 10) when the temperature of the inner brake pad 6 in the vehicle width direction differs from the temperature of the outer brake pad 8 in the vehicle width direction (for example, when the difference between the two temperatures exceeds a temperature threshold difference). Similarly, the control device 108 may be configured to determine that one of the inner and outer brake pads 6, 8 is not functioning properly during braking (for example, not engaged with the corresponding braking surfaces 11A, 11B, respectively, or engaged with weak force) when the temperature of the inner brake pad 6 in the vehicle width direction differs from the temperature of the outer brake pad 8 in the vehicle width direction.

[0221] In other embodiments, the control device 108 is not configured to determine the braking state of the heavy vehicle disc brake 2. Instead, the braking state may be determined manually or by an external system (e.g., an external monitoring system 120) based on the calculated temperatures of the brake pads 6, 8 and / or rotor 10.

[0222] In the illustrated embodiment, it is understood that the travel distance between the ultrasonic emitter 104 and the ultrasonic sensor 106 depends on the thickness of the respective brake pads 6, 8 and / or rotor 10. However, the thickness of the brake pads 6, 8 and / or rotor 10 decreases over time (due to wear of the friction material 14 and / or rotor material during braking). Therefore, in some embodiments, the control device 108 is configured to receive the determined thickness of the brake pads 6, 8 and / or rotor 10 from the wear sensor assembly. The wear sensor assembly may be a steady-state wear sensor (CWS) assembly. Alternatively, the wear sensor assembly may measure the thickness of the respective brake pads 6, 8 using ultrasonic devices 102A, 102B (for example, by utilizing one or more of the methods outlined in European Patent Applications EP23179290.4 and EP23188733.2, which are incorporated herein by reference). In such embodiments, the control device 108 may perform operations to determine both the temperature and thickness of the respective brake pads 6, 8 and / or rotor 10.

[0223] In some embodiments, one of the first or second ultrasonic devices 102A, 102B is omitted. In such embodiments, the control device 108 may be configured to calculate the temperature of only one of the brake pads 6, 8.

[0224] In some embodiments, one of the ultrasonic devices 102A and 102B has an ultrasonic emitter 104 but no ultrasonic sensor 106, while the other ultrasonic device 102A and 102B has an ultrasonic sensor 106 but no ultrasonic emitter 104. In such embodiments, the control device 108 may be configured to calculate the temperature of the rotor 10 rather than the temperature of the brake pads 6 and 8.

[0225] Referring here to Figures 5A and 5B, the ultrasonic device 102 is shown in more detail. It will be understood that the first and / or second ultrasonic devices 102A, 102B may be configured in this way. The ultrasonic device 102 in Figures 5A and 5B has a housing 126 for an ultrasonic emitter 104 and / or an ultrasonic sensor 106. The ultrasonic device 102 also has a spacing member 128 that separates the ultrasonic emitter 104 and the ultrasonic sensor 106 from the corresponding damping surfaces 11A, 11B, respectively, when the ultrasonic device 102 is engaged. The spacing member 128 may include part of the housing 126 and / or a sacrificial member (as will be described in more detail later).

[0226] The ultrasonic emitter 104 is any suitable emitter that generates high-frequency ultrasonic waves, and the ultrasonic sensor 106 is any suitable sensor. Examples of suitable ultrasonic emitters 104 and sensors 106 are piezoelectric transducers or electromagnetic acoustic transducers (EMATs). In some embodiments, the ultrasonic emitter 104 and sensor 106 may be provided by the same component (e.g., the same transducer). In such embodiments, it is understood that the transducer emits high-frequency sound waves and also detects high-frequency sound waves (e.g., reflections of emitted high-frequency sound waves and / or high-frequency sound waves emitted by different ultrasonic devices).

[0227] The high-frequency sound waves detected by the ultrasonic sensor 106 can be transmitted to a suitable control device (e.g., the control device 108 described above) via the connecting wire 130, or wirelessly in other embodiments.

[0228] In the illustrated embodiment, the spacing member 128 is an elongated sacrificial member having a longitudinal axis xx. In this embodiment, the sacrificial member 128 is fixed to the housing 126 with a suitable adhesive, but in other embodiments, the sacrificial member 128 and the housing 126 each have corresponding threads and can be screwed to each other. Alternatively, the sacrificial member 128 may be interference fit with the housing 126. Furthermore, since the ultrasonic emitter 104 and sensor 106 are located within the housing 126, the sacrificial member 128, housing 126, ultrasonic emitter 104, and sensor 106 can all be provided as a single ultrasonic device 102. Typically, the remaining portion of the housing 126 can be filled with epoxy resin or similar material to position the ultrasonic emitter 104 and sensor 106. In other embodiments, it is understood that all components can be provided separately, insofar as the sacrificial member 128 is positioned between the ultrasonic emitter 104 and sensor 106 and the corresponding braking surfaces 11A and 11B of the disc brake 2, respectively, so that sound waves from the ultrasonic emitter 104 pass through the sacrificial member 128 and can optionally be reflected and detected by the ultrasonic sensor 106.

[0229] The couplant 132 may be provided between the ultrasonic emitter 104 and sensor 106 and the end of the sacrificial member 128 so as not to have an air gap between them. Thus, the couplant 132 acts as a bridge to ensure that sound waves are reliably propagated to the sacrificial member 128 and that the signal is not adversely affected by passing through air. The couplant 132 may be in the form of a solid disk made of any suitable material, or it may be a viscous liquid, such as a silicone-based or glycol-based gel.

[0230] The sacrificial member 128 is formed from a homogeneous material to ensure that sound waves from the ultrasonic emitter 104 pass easily through the sacrificial member 128 and can be detected without causing significant interference that would affect the signal. Any suitable material can be used, but ideally the material of the sacrificial member 128 should be heat-resistant so as to withstand the high temperatures reached by the brakes and should have similar compressibility to the friction material 14 of the brake pads 6, 8. Examples of suitable materials include thermoplastics such as Vespec®.

[0231] The free end of the sacrificial member 128 has an engagement surface 134. The engagement surface 134 is approximately perpendicular to the longitudinal axis xx. As shown in Figures 2 and 4, when mounted on the brake, the sacrificial member 128 is positioned such that its longitudinal axis xx extends perpendicular to the engagement surface 16 of the friction material 14 of the respective brake pads 6 and 8. This ensures that the engagement surface 134 of the sacrificial member 128 faces the corresponding braking surfaces 11A and 11B and is flush with the engagement surface 16 of the friction material 14 of the respective brake pads 6 and 8.

[0232] The brake pads 6, 8 and the corresponding sacrificial member 128 are configured to work together during braking, so that the engagement surface 134 of the sacrificial member 128 also engages with the rotor 10. Therefore, as the friction material 14 wears down, the sacrificial member 128 wears down at the same rate. Thus, sound waves emitted from the ultrasonic emitter 104 through the sacrificial member 128 are reflected by the ultrasonic sensor 106 when they come into contact with the engagement surface 134 of the sacrificial member 128 at the interface between the material of the sacrificial member 128 and the air surrounding the sacrificial member 128 and / or the rotor 10. The reflected sound waves are detected by the ultrasonic sensor 106, which can provide data indicating the time delay between the transmission and reception of the sound waves, thereby indicating the amount of material remaining on the sacrificial member 128. This data can then be used to determine the wear of the friction material 14 corresponding to the wear of the sacrificial member 128, since the friction material 14 and the sacrificial member 128 are flush.

[0233] This calculated amount of material remaining on the sacrificial member 128 may be used by the control device 108, as described above in relation to Figures 2 and 4, to calculate the thickness of the rotor 10. For example, the control device 108 may calculate the total distance between the ultrasonic emitter of the first ultrasonic device 102A and the ultrasonic sensor 106 of the second ultrasonic device 102B, and then subtract the length of material remaining on the sacrificial members 128 of the first and second ultrasonic devices 102A and 102B to determine the thickness of the rotor 10.

[0234] Furthermore, the calculated amount of material remaining on the sacrificial member 128 may be used by the control device 108, as described above in relation to Figures 2 and 4, to calculate the temperature of each brake pad 6, 8 and / or rotor 10. For example, the control device 108 may use the length of the material remaining on the sacrificial member 128 to determine the distance traveled by the high-frequency sound wave, and use this distance to calculate the velocity of the high-frequency sound wave when performing temperature measurement.

[0235] Since the high-frequency sound waves pass through the sacrificial members 128 rather than the friction material 14 of each brake pad 6, 8, it is understood that the control device 108 is configured to calculate the temperature of the sacrificial members 128 rather than the temperature of the friction material 14. However, since the sacrificial members 128 are embedded in the friction material, the temperature of the sacrificial members 128 changes with the temperature of the friction material 14. For example, when each brake pad 6, 8 is in a dragging state, the temperature of the friction material 14 rises, which causes a corresponding rise in the temperature of the sacrificial members 128 that can be detected by the control device 108. Since the cross-sectional area of ​​the sacrificial members 128 is smaller than that of the friction material 14, the sacrificial members 128 will be at substantially the same temperature as the friction material 14, even if the material of the sacrificial members 128 has a lower thermal conductivity than the material of the friction material 14.

[0236] It is understood that the temperatures of the brake pads 6, 8 and / or rotor 10 change over a shorter period (e.g., during and after braking) compared to the change in thickness of the brake pads 6, 8 or rotor 10 due to wear. Therefore, two relevant measurements, thickness and sound velocity (to calculate temperature), may be determined by taking measurements at different times and on different time scales using the same ultrasonic emitter 104 and sensor 106. For example, the above thickness measurement (using the methods and apparatus outlined, for example, in European Patent Applications EP23179290.4 and EP23188733.2, incorporated herein by reference) may be performed once a day after a period of vehicle inactivity, provided that the ambient temperature and the temperature of the brake pads 6, 8 or rotor 10 are known. This may be stored in memory 116 for use by the control unit 108 for temperature calculations performed during active use of the brakes (e.g., while driving a heavy vehicle).

[0237] In some embodiments, the control device 108 may be configured to determine the braking state of the heavy vehicle brake assembly 2 by identifying changes in high-frequency sound waves detected by the ultrasonic sensors 106 of the first and / or second ultrasonic devices 102A, 102B. For example, the control device 108 may be configured to determine when one or both of the brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B by identifying changes (e.g., increases) in the amplitude of the high-frequency sound waves detected by each ultrasonic sensor 106. This may be used to determine that a braking operation is being performed (e.g., when both brake pads 6, 8 are in contact with the corresponding braking surfaces 11A, 11B). Alternatively, this may be used to determine a malfunction of the heavy vehicle brake assembly 2, such as a dragging brake pad 6, 8 (e.g., when only one brake pad 6, 8 is in contact with the corresponding braking surface 11A, 11B).

[0238] Figure 6 shows an alternative brake for a heavy vehicle. In this embodiment, a drum brake 202 for a heavy vehicle having an actuator 204 is shown. In this embodiment, the braking elements are brake shoes 206, each having a friction material 214. The operation of such a drum brake 202 is well known and will not be described in detail, but briefly, during braking, the actuator 204 acts the brake shoes 206 radially outward, so that the friction material 214 of each brake shoe engages with the braking surface 211, which is the inner surface of a drum 210 that is rotatably fixed relative to the vehicle wheel, thereby decelerating the vehicle. An ultrasonic device 102 (for example, of the type shown in Figures 5A and 5B) is installed facing the braking surface 211 and is flush with the engagement surface 216 of the friction material 214.

[0239] The ultrasonic device 102 may have an ultrasonic emitter and an ultrasonic sensor, and the thickness of the drum 210 may be determined by detecting high-frequency sound waves emitted from the ultrasonic emitter and then reflected back to the ultrasonic sensor at the material boundary on the outer surface 213 of the drum 210 (for example, by measuring the time delay as described in detail above and using it to calculate the thickness). Alternatively, the temperature of each brake shoe 206 may be determined using a method similar to that described above for the disc brake embodiments of Figures 1 to 4.

[0240] The drum brake 202 may be part of a heavy vehicle brake system having a control device 108 configured similarly to the control device 108 of the heavy vehicle brake system 100 described above.

[0241] Referring to Figure 7, a flowchart shows a method for measuring the thickness of braking components (e.g., rotor 10 or drum 210) in a brake assembly for a heavy vehicle (e.g., a disc brake 2 or drum brake 202 for a heavy vehicle). An example of how this method is implemented in a heavy vehicle braking system 100 having a control device 108 has been described in detail above. However, in summary, the method includes the steps described below.

[0242] The method comprises providing an ultrasonic device having an ultrasonic emitter (for example, providing the ultrasonic device 102 described above, a mobile probe including an ultrasonic emitter, or any other suitable ultrasonic device), wherein the ultrasonic device is movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface of a braking component and an engaged state in which the ultrasonic device is in contact with the braking surface.

[0243] The method further includes determining whether the ultrasonic device is engaged (for example, by using one of the methods performed by the control device 108 in the above description, or by any other suitable means such as manual inspection by an operator).

[0244] The method further includes, when it is determined that the ultrasonic device is in an engaged state, emitting high-frequency sound waves through a damping component with an ultrasonic emitter, and detecting the high-frequency sound waves with an ultrasonic sensor.

[0245] The method further includes measuring the time delay between the transmission and detection of high-frequency sound waves, and calculating the thickness of the damping component based on the time delay.

[0246] The method further includes an optional step (indicated by dashed lines) of determining the wear condition of a braking component (for example, based on changes in the thickness of the braking component over time and / or a comparison with the thickness of another braking component on the same vehicle).

[0247] The method further includes an optional step (shown by a dashed line) of determining the temperature of the brake assembly, calibrating the thickness calculation using the determined temperature of the brake assembly, and / or determining whether the temperature of the brake assembly is within a predetermined temperature range, and emitting / detecting high-frequency sound waves only if the temperature of the brake assembly is within the predetermined temperature range.

[0248] The method further includes optional steps (indicated by dashed lines) of displaying the calculated thickness, recording the calculated thickness in memory, and / or transmitting the calculated thickness to a thickness monitoring system.

[0249] The method further includes optional steps (indicated by dashed lines) of displaying the determined wear condition, recording the determined wear condition in memory, and / or transmitting the determined wear condition to a wear monitoring system.

[0250] Referring to Figure 8, a flowchart shows a method for determining the braking state of a brake assembly for a large vehicle (for example, a disc brake 2 or drum brake 202 for a large vehicle). An example of implementing this method in a large vehicle braking system 100 having a control device 108 has been described in detail in the above description. However, in summary, the method includes the steps described later.

[0251] The method includes providing an ultrasonic device having an ultrasonic emitter (for example, providing the ultrasonic device 102 described above), wherein the ultrasonic device is movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface of the braking component and an engaged state in which the ultrasonic device is in contact with the braking surface.

[0252] The method further includes emitting high-frequency sound waves through a damping component using an ultrasonic emitter, and detecting the high-frequency sound waves with an ultrasonic sensor.

[0253] The method further includes determining the braking state of a heavy vehicle brake assembly by identifying changes in high-frequency sound waves detected by an ultrasonic sensor. For example, this may include determining when a braking element is in contact with the braking surface of a braking component by identifying an increase in the amplitude of high-frequency sound waves detected by the ultrasonic sensor. This may be used to determine that a braking element is in a dragging state when it is determined that the heavy vehicle brake assembly is not performing a braking action.

[0254] Referring to Figure 9, a flowchart shows a method for measuring the temperature of braking elements (e.g., brake pads 6, 8, rotor 10, or brake shoe 206) in a brake assembly for a heavy vehicle (e.g., a disc brake 2 or drum brake 202 for a heavy vehicle). An example of implementing this method in a brake system 100 for a heavy vehicle having a control device 108 has been described in detail above. However, in summary, the method includes the steps described below.

[0255] The method includes emitting high-frequency sound waves through a damping element using an ultrasonic emitter, and detecting the high-frequency sound waves with an ultrasonic sensor.

[0256] The method further includes measuring the time delay between the transmission and detection of high-frequency sound waves.

[0257] The method further includes calculating the temperature of the damping element based on the time delay and the distance traveled by the high-frequency sound wave between the ultrasonic sensor and the ultrasonic emitter.

[0258] In some embodiments, calculating the temperature of the damping element may include calculating the velocity of the high-frequency sound wave passing through the damping element by dividing the distance traveled by the high-frequency sound wave by a time delay. The method may then include determining the temperature of the damping element based on the velocity of the high-frequency sound wave passing through the damping element by inputting, for example, the calculated velocity of the high-frequency sound wave into a mathematical function that defines the relationship between the velocity of sound and temperature for the damping element. The mathematical function may be determined from experimental data, including measurements of the velocity of sound obtained through the material of the damping element at a number of known temperatures, for example, by using curve fitting techniques such as regression or interpolation.

[0259] In some embodiments, the distance traveled by high-frequency sound waves through the braking element is based on the thickness of the braking element, which can be determined by a wear sensor assembly (for example, a wear sensor assembly using an ultrasonic emitter and an ultrasonic sensor, as disclosed in European Patent Application EP23179290.4, incorporated herein by reference).

[0260] The method shown in Figure 9 may be used to determine the temperature of the brake pads 6, 8 or brake shoes 206, as described above in relation to Figures 1 to 6. The method shown in Figure 9 may also be used to determine the temperature of the rotor 10 or drum 210.

[0261] Referring to Figure 10, a flowchart shows a method for determining the braking state of a brake assembly for a large vehicle (for example, a disc brake 2 or drum brake 202 for a large vehicle). An example of implementing this method in a brake system 100 for a large vehicle having a control device 108 has been described in detail above. However, in summary, the method includes the steps described later.

[0262] The method in Figure 10 first involves determining the temperature of the braking elements of a brake assembly for a large vehicle using the method in Figure 9. Next, the method in Figure 10 involves determining the braking state from the measured temperature.

[0263] In some embodiments, the braking element is a brake pad 6, 8 or brake shoe 206, and the method includes determining that dynamic braking action is being performed when the measured temperature of the brake pad 6, 8 is rising (i.e., determining that the engagement surface is engaging with the braking surface and slowing down the heavy vehicle). In this context, the term “dynamic braking action” means that the braking element (e.g., brake pad 6, 8 or brake shoe 206) is engaged with a brake component (e.g., rotor 10 or drum 210), but there is relative motion between them, which generates friction and causes a temperature rise. Dynamic braking action is performed to slow down or limit the acceleration of a heavy vehicle. This is in contrast to “static braking action,” in which there is no relative motion between the braking element and the brake component, and therefore no corresponding temperature rise.

[0264] In some embodiments, the determination that dynamic braking is occurring may be used to identify a faulty braking condition (e.g., a dragging brake). For example, if the temperature of the braking elements is rising, but the brake assembly for a heavy vehicle is not acting to apply the brakes, this may indicate that the brakes are dragging.

[0265] Referring to Figure 11, a flowchart shows a further method for determining the braking state of a brake assembly for a heavy vehicle (e.g., a disc brake 2 or drum brake 202 for a heavy vehicle). An example of how this method is implemented in a heavy vehicle brake system 100 having a control device 108 has been described in detail above. However, in summary, the method includes the steps described later.

[0266] The method in Figure 11 includes determining the temperature of a first braking element (e.g., a brake pad 6 on the inside in the vehicle width direction) of a brake assembly for a large vehicle using the method in Figure 9. The method also includes determining the temperature of a second braking element (e.g., a brake pad 8 on the outside in the vehicle width direction) of the brake assembly for a large vehicle using the method in Figure 9. Furthermore, the method in Figure 11 includes determining that one of the first or second braking elements is in a dragging state if the temperature of the first braking element is different from the temperature of the second braking element (e.g., if the temperature difference between the first and second braking elements exceeds a threshold temperature difference).

[0267] The method shown in Figure 11 is based on the fact that a dragging braking element causes a temperature increase due to dynamic braking force.

[0268] In some embodiments, a method similar to that shown in Figure 10 or Figure 11 may be used to determine if a braking element is not properly applied. For example, if a braking element (e.g., brake pads 6, 8, or brake shoes 206) is stuck in a disengaged position from a braking component (e.g., rotor 10 or drum 210) or is not engaged with the braking component with sufficient force, this can be determined by identifying a lower-than-expected temperature change during braking. For example, if one braking element is not properly applied, this can be determined by identifying a lower temperature rise for that braking element compared to other braking elements in a heavy vehicle brake assembly.

[0269] As described in detail above, the use of high-frequency sound waves to determine the temperature of the braking element is understood to be based on the principle that the speed of sound passing through the braking element changes with the temperature of the braking element. Figure 12 is a graph of experimental results illustrating this phenomenon. These experimental results were obtained by measuring the time delay between the emission and detection of high-frequency sound waves through brake pads 6, 8 at different known temperatures over multiple braking cycles, using a large vehicle disc brake assembly similar to those shown in Figures 1 to 4.

[0270] The graph includes a right-hand Y-axis showing temperature in Celsius and a left-hand Y-axis showing "time of flight" in μs (i.e., the time delay between the transmission and detection of high-frequency sound waves). The X-axis represents the time and date when each temperature and time of flight measurement was taken.

[0271] Temperature measurements are performed using thermocouples embedded in the friction material 14 of brake pads 6 and 8, and are indicated by an "X". Flight time measurements are shown as a solid line above the temperature "X" marks.

[0272] As can be seen from Figure 12, there were multiple first measurements M1 performed at approximately 100°C, multiple second measurements M2 performed at approximately 170°C, and multiple third measurements M3 performed at approximately 250°C.

[0273] To reach the desired temperature for measuring flight time, the brake pads 6 and 8 were engaged with the rotor 10 in a dynamic braking action, thereby increasing their temperature using friction. Once the thermocouple readings reached a sufficient temperature, the flight time was measured, and the process was repeated after the brake pads 6 and 8 had cooled. Because dynamic braking was used to increase the temperature of the brake pads 6 and 8, the friction material 14 of the brake pads 6 and 8 wore down during the experiment (i.e., the thickness of the friction material 14 and the thickness of the sacrificial member 128 decreased). This resulted in a corresponding decrease in flight time, which can be seen in the downward-sloping flight time values ​​in each measurement set M1, M2, and M3 (where the temperature was approximately constant).

[0274] If the thickness of brake pads 6 and 8 at each measurement of flight time is known (for example, by using data from a wear monitoring system), it is understood that the flight time measurements can be converted into measurements of the speed of sound, which is approximately constant within a certain temperature range (i.e., within measurement sets M1, M2, and M3). Subsequently, experimental data points can be generated using the average speed of sound measurements for each temperature, and a mathematical function for calculating temperature from the speed of sound measurements can be defined by applying curve fitting techniques to these data points. For example, Figure 13 shows an example of a graph of such a mathematical function in which linear interpolation is used between data points. In this way, when a new speed of sound measurement is made at an unknown temperature, the temperature of brake pads 6 and 8 can be estimated by interpolating between data points (for example, as shown by the dashed arrows in Figure 13). Such a mathematical function may be used by the control device 108 described above and / or in the method of Figure 9.

[0275] The word "or" should be interpreted as meaning "and / or," and the items being referred to are not necessarily mutually exclusive and can be used in any appropriate combination.

[0276] Although the present invention has been described above with reference to one or more preferred embodiments, it will be understood that various changes or modifications are possible without departing from the scope of the invention as defined in the appended claims.

[0277] Furthermore, while the attached claims describe specific combinations of the features described above, it should be noted that the scope of this disclosure is not limited to the specific combinations described in the following claims, but extends to encompass any combination of the features disclosed herein.

Claims

1. A method for measuring the temperature of braking elements in a brake assembly for a large vehicle, a) A process of transmitting high-frequency sound waves through a damping element using an ultrasonic emitter and detecting the high-frequency sound waves using an ultrasonic sensor. b) A step of measuring the time delay between the transmission and detection of high-frequency sound waves, c) A step of calculating the temperature of the damping element based on the time delay and the distance traveled by the high-frequency sound wave between the ultrasonic sensor and the ultrasonic emitter. A method of having.

2. The method according to claim 1, Step c) is, c1) A step of calculating the velocity of the high-frequency sound wave passing through a damping element by dividing the distance traveled by the high-frequency sound wave by the time delay, and c2) A step of determining the temperature of a braking element based on the speed of high-frequency sound waves passing through the braking element. A method having

3. The method according to claim 2, Step c2) is a method comprising inputting the calculated high-frequency sound wave velocity into a mathematical function that defines the relationship between the speed of sound and temperature for a damping element.

4. The method according to claim 3, The mathematical function was determined from experimental data, including measurements of the speed of sound obtained through the damping element material at multiple known temperatures. The mathematical function is determined from experimental data using curve fitting techniques, at the discretion of the user. A method in which a mathematical function is arbitrarily determined from experimental data using regression or interpolation.

5. A method according to any one of claims 1 to 4, The distance traveled by high-frequency sound waves is based on the thickness of the damping element. The thickness of the braking element is determined by the wear sensor assembly. Optionally, the wear sensor assembly comprises an ultrasonic emitter and an ultrasonic sensor.

6. A method according to any one of claims 1 to 5, The braking element has a support surface that supports a friction material having an engagement surface, The braking element is configured such that, when activated during braking, its engaging surface engages with the braking surface to decelerate the large vehicle. The braking element is optionally a brake pad for a disc brake or a brake shoe for a drum brake.

7. The method according to claim 6, The process further includes measuring the temperature of a braking component having a braking surface configured to be engaged by a braking element to decelerate a large vehicle, A method in which, optionally, the braking component is either a rotor for a disc brake or a drum for a drum brake.

8. A method for determining the braking state of a brake assembly for a large vehicle, A step of measuring the temperature of a braking element of a brake assembly for a large vehicle using the method according to any one of claims 1 to 7, and A process for determining the braking state from the measured temperature. A method of having.

9. The method according to claim 8, The braking element has a support surface for supporting a friction material having an engagement surface, and the braking element is configured such that, when actuated during braking, the engagement surface engages with the braking surface of a heavy vehicle brake assembly to decelerate the heavy vehicle, and the method includes the step of determining that when the measured temperature is rising, the engagement surface is engaging with the braking surface to decelerate or limit the acceleration of the heavy vehicle, and / or A method comprising the steps of: measuring the temperature of a first braking element using the method according to any one of claims 1 to 7; measuring the temperature of a second braking element using the method according to any one of claims 1 to 7; and determining that one of the first braking element and the second braking element is in a dragging state if the temperature of the first braking element is different from the temperature of the second braking element, optionally wherein this is the case when the temperature difference between the first braking element and the second braking element exceeds a threshold temperature difference.

10. A brake system for large vehicles, A brake assembly for a large vehicle comprising a braking element including a braking component and a friction material having an engaging surface, an ultrasonic emitter, an ultrasonic sensor, and a control device, The braking element is configured such that, when activated during braking, the engagement surface of the friction material engages with the braking surface of the braking component, thereby decelerating the large vehicle. The control device is a) The ultrasonic emitter is instructed to emit high-frequency sound waves through at least one of the braking element and braking component so that they can be detected by an ultrasonic sensor, and a signal indicating the detected high-frequency sound waves is received from the ultrasonic sensor. b) Measure the time delay between the transmission and detection of high-frequency sound waves. c) Calculate the temperature of at least one of the braking element and braking component based on the time delay and the distance traveled by the high-frequency sound wave between the ultrasonic emitter and the ultrasonic sensor. A brake system for large vehicles, configured as follows.

11. A brake system for large vehicles according to claim 10, The control device, in process c), c1) The speed of the high-frequency sound wave passing through at least one of the damping element and damping component is calculated by dividing the distance traveled by the time delay. c2) Determine the temperature of at least one of the braking element and braking component based on the velocity of high-frequency sound waves passing through at least one of the braking element and braking component. It is structured in such a way, This is done by optionally inputting the calculated high-frequency sound wave velocity into a mathematical function that defines the relationship between sound velocity and temperature for at least one of the braking element and braking component. Optionally, the mathematical function is determined from experimental data including sound velocity measurements obtained through at least one of the materials of the braking element and braking component at multiple known temperatures. The mathematical function is determined from experimental data using curve fitting techniques, at the discretion of the user. A brake system for large vehicles in which, optionally, the mathematical function is determined from experimental data using regression or interpolation.

12. A brake system for large vehicles according to claim 10 or 11, The ultrasonic emitter and ultrasonic sensor are positioned on the opposite side of the engagement surface in the friction material of the braking element, so that high-frequency sound waves emitted from the ultrasonic emitter are reflected at the engagement surface and detected by the ultrasonic sensor, or A brake system for large vehicles in which the ultrasonic emitter and ultrasonic sensor are located on opposite sides of the braking components, so that high-frequency sound waves emitted from the ultrasonic emitter pass through the braking components and reach the ultrasonic sensor.

13. A disc brake comprising a brake system for large vehicles according to any one of claims 10 to 12, The braking component is a rotor that is fixed in rotation relative to the vehicle wheel. The braking element or each braking element is a brake pad having a friction material, Optionally, a disc brake where the brake pads have a backing plate and the friction material is fixed to the backing plate.

14. A drum brake comprising a brake system for large vehicles according to any one of claims 10 to 12, The braking component is a rotor that is fixed in rotation relative to the vehicle wheel. The braking element or each braking element is a brake pad having a friction material, Optionally, a drum brake where the brake pads have a backing plate and the friction material is fixed to the backing plate.

15. A control device for a brake system for large vehicles, a) An ultrasonic emitter is instructed to emit high-frequency sound waves through at least one of the braking elements and braking components of a brake system for large vehicles so that they can be detected by an ultrasonic sensor, and a signal indicating the detected high-frequency sound waves is received from the ultrasonic sensor. b) Measure the time delay between the transmission and detection of high-frequency sound waves. c) Calculate the temperature of at least one of the braking element and braking component based on the time delay and the distance traveled by the high-frequency sound wave between the ultrasonic emitter and the ultrasonic sensor. A control device configured in such a way.

16. A method for measuring the thickness of a braking component in a brake assembly for a large vehicle, which includes a braking element containing a friction material having an engagement surface, The braking element is configured such that, when activated during braking, the engagement surface of the friction material engages with the braking surface of the braking component, thereby decelerating the large vehicle. The method is, a) A step of providing an ultrasonic device having an ultrasonic emitter, wherein the ultrasonic device is movable between an unengaged state in which the ultrasonic device is not in contact with a braking surface and an engaged state in which the ultrasonic device is in contact with a braking surface. b) A step of determining when the ultrasonic device is in an engaged state, c) When it is determined that the ultrasonic device is in an engaged state, the ultrasonic emitter is used to emit high-frequency sound waves through the damping components, and the ultrasonic sensor is used to detect the high-frequency sound waves. d) A step of measuring the time delay between the transmission and detection of high-frequency sound waves, e) A step of calculating the thickness of the braking component based on the time delay, Methods that include...

17. The method according to claim 16, The ultrasonic device having an ultrasonic emitter is a first ultrasonic device located on the first side of the damping component, The ultrasonic sensor is part of a second ultrasonic device located on the second side of the braking component, which is opposite the first side. The braking component has a first braking surface on the first side and a second braking surface on the second side. The second ultrasonic device is movable between an unengaged state in which the second ultrasonic device is not in contact with the second braking surface and an engaged state in which the second ultrasonic device is in contact with the second braking surface. Step b) is a method comprising determining whether both the first ultrasonic device and the second ultrasonic device are engaged.

18. The method according to claim 17, The brake assembly comprises a first braking element and a second braking element, each including a friction material having an engagement surface. The first braking element and the second braking element are configured such that when activated during braking, their engaging surfaces engage with the first braking surface and the second braking surface, respectively, to decelerate the large vehicle. The first ultrasonic device is fixed relative to the first damping element. A method in which the second ultrasonic device is fixed relative to the second damping element.

19. A method according to any one of claims 16 to 18, Step b) is a method comprising the step of determining whether the engaging surfaces of the braking elements or the friction material of each braking element are in contact with the corresponding braking surfaces.

20. The method according to claim 19, Step b) includes the step of transmitting a command to the brake control system to activate the braking element or each braking element so that they engage with the corresponding braking surface, Optionally, the brake control system includes a separate brake system and / or Optionally, a command is transmitted to the brake control system when a large vehicle is started.

21. The method according to claim 19 or 20, Step b) is, A step of receiving a signal from at least one of a brake pedal sensor and a brake control system, A process of measuring the pressure in a hydraulic or pneumatic brake line connected to a braking element or an actuator for operating each braking element. A process for identifying changes in high-frequency sound waves detected by an ultrasonic sensor, and A process for measuring the current in an electrical circuit connected to a braking element or an electrical actuator for operating each braking element. A method that includes at least one of the following.

22. A method according to any one of claims 16 to 21, f) A step of determining the wear state of the braking components based on the change in the thickness of the braking components over time, Optionally, step f) includes comparing the thickness of the braking component calculated in step e) with a reference thickness stored in memory, wherein the reference thickness includes at least one of the initial thickness of the braking component and the thickness of one or more previously calculated braking components, and / or The method optionally includes at least one of the following steps: displaying the wear condition determined in step f) audibly and / or visually; recording the wear condition determined in step f) in memory; and transmitting the wear condition determined in step f) to a wear monitoring system.

23. A method according to any one of claims 16 to 22, Step e) A step of displaying the thickness of the braking component calculated in step e) audibly and visually, A step of recording the thickness of the braking component calculated in step e) into memory, and Step e) A step of transmitting the thickness of the braking component calculated in step e) to the thickness monitoring system, A method that includes at least one of the following.

24. A method according to any one of claims 16 to 23, A method comprising the steps of determining the temperature of a brake assembly and using the determined temperature of the brake assembly to calibrate the calculation in step e).

25. A method according to any one of claims 16 to 23, The process includes determining whether the temperature of the brake assembly is within a predetermined temperature range, Step c) is performed only when it is determined that the temperature of the brake assembly is within a predetermined temperature range. A method comprising, optionally, determining whether the temperature of a brake assembly is within a predetermined temperature range, including at least one of the following steps: determining that a predetermined time has elapsed since the last braking operation; determining that a large vehicle has been started after a period of being stopped; and measuring or estimating the temperature of the brake assembly using a temperature sensor.

26. A large vehicle braking system, It includes a brake assembly for large vehicles, an ultrasonic device, an ultrasonic sensor, and a control device. A brake assembly for a large vehicle comprises a braking component and a braking element including a friction material having an engagement surface. The braking element is configured such that, when activated during braking, the engagement surface of the friction material engages with the braking surface of the braking component, thereby decelerating the large vehicle. The ultrasonic device has an ultrasonic emitter, The ultrasonic device is movable between an unengaged state in which the ultrasonic device is not in contact with the braking surface and an engaged state in which the ultrasonic device is in contact with the braking surface. The control device is e) Determine if the ultrasonic device is engaged, f) When it is determined that the ultrasonic device is engaged, the ultrasonic emitter is instructed to emit high-frequency sound waves through the damping component so that they can be detected by the ultrasonic sensor, and a signal indicating the detected high-frequency sound waves is received from the ultrasonic sensor. G) Measure the time delay between the emission and detection of high-frequency sound waves. h) Calculate the thickness of the braking components based on the time delay. A large vehicle braking system configured as follows.

27. A large vehicle braking system according to claim 26, The ultrasonic device having an ultrasonic emitter is a first ultrasonic device located on the first side of the damping component, The ultrasonic sensor is part of a second ultrasonic device located on the second side of the braking component, which is opposite the first side. The braking component has a first braking surface on the first side and a second braking surface on the second side. The second ultrasonic device is movable between an unengaged state in which the second ultrasonic device is not in contact with the second braking surface and an engaged state in which the second ultrasonic device is in contact with the second braking surface. A large vehicle braking system in which the control device is configured to determine in step a) whether the first ultrasonic device and the second ultrasonic device are engaged.

28. A large vehicle braking system according to claim 27, The brake assembly for large vehicles comprises a first braking element and a second braking element, each containing a friction material having an engagement surface. The first braking element and the second braking element are configured to be activated during braking, causing their engagement surfaces to engage with the corresponding first and second braking surfaces, respectively, thereby decelerating the large vehicle. A heavy-duty vehicle braking system in which a first ultrasonic device is fixed relative to a first braking element, and a second ultrasonic device is fixed relative to a second braking element.

29. A heavy vehicle braking system according to any one of claims 26 to 28, The control unit is a heavy-duty vehicle braking system that is mounted on a brake assembly for heavy-duty vehicles.

30. A disc brake having a large vehicle braking system according to any one of claims 26 to 29, The braking surface is a rotor that is fixed in rotation relative to the vehicle wheel. The braking element or each braking element is a brake pad having a friction material, Optionally, a disc brake where the brake pads have a backing plate and the friction material is fixed to the backing plate.

31. A control device for a brake system for large vehicles, a) An ultrasonic emitter is instructed to emit high-frequency sound waves through the braking components of a brake assembly for a large vehicle so that they can be detected by an ultrasonic sensor, and a signal indicating the detected high-frequency sound waves is received from the ultrasonic sensor. b) Determine the braking state of a brake assembly for a large vehicle by identifying changes in high-frequency sound waves detected by an ultrasonic sensor. A control device configured in such a way.

32. A control device for a brake system for large vehicles, a) The ultrasonic device of the brake system for large vehicles is determined to be in an engaged state in which the ultrasonic device is in contact with the braking surface of the braking component of the brake system for large vehicles. b) When it is determined that the ultrasonic device is engaged, the ultrasonic emitter of the ultrasonic device is instructed to emit high-frequency sound waves through the braking components so that they can be detected by the ultrasonic sensor of the heavy vehicle brake system, and a signal indicating the detected high-frequency sound waves is received from the ultrasonic sensor. c) Measure the time delay between the transmission and detection of high-frequency sound waves. d) Calculate the thickness of the braking components based on the time delay. A control device configured in such a way.

33. A control device according to claim 32, e) A control device configured to determine the wear state of a braking component based on the change in the thickness of the braking component over time.

34. A control device according to claim 32 or 33, A control device in step a), wherein both a first ultrasonic device located on the first side of the braking component and a second ultrasonic device located on the second side of the braking component are configured to determine whether the ultrasonic devices are in an engaged state, in contact with the corresponding braking surfaces of the braking component.

35. The control device according to claim 32, 33, or 34 The control device is configured to determine the temperature of the brake assembly and to use the determined temperature of the brake assembly to calibrate the calculation in step d). Optionally, the control device is configured to determine the temperature of the brake assembly based on a signal received from a temperature sensor and / or by monitoring the operating conditions of the brake assembly. The control device is configured to determine whether the temperature of the brake assembly is within a predetermined temperature range, and to execute step b) only when it is determined that the temperature of the brake assembly is within the predetermined temperature range. The control device is optionally configured to determine whether the temperature of the brake assembly is within a predetermined temperature range by determining that a predetermined time has elapsed since the last braking operation, determining that the heavy vehicle has been started after a period of stopping, and measuring or estimating the temperature of the brake assembly based on a signal from a temperature sensor.

36. A component kit comprising a control device according to claim 15 or any one of claims 31 to 35, an ultrasonic emitter, and an ultrasonic sensor.

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