Vehicle electronic systems, including parking brake devices

Abstract

1. A vehicle electronics system including a parking brake device comprising a brake element (2) comprising either a brake pad or a brake shoe, the brake element (2) including an electrical circuit with one or more sensors (3, 4, 5) for real-time detection of signals related to temperature and / or normal force and / or shear force, and having electrical terminals arranged in zones for collecting signals from the brake element, the vehicle electronic parking brake system further comprising an actuator (8) of the brake element (2), a controller (7) for sending braking force commands to the actuator (8), and regulating means (9, 10) for driving the controller (7), the regulating means (9, 10) including a closed braking force regulation loop including a reference braking force generator (10), the closed braking force regulation loop communicating with the sensors (3, 4, 5) to obtain at least one of the temperature and / or normal force and / or shear force measurements.

Description

[Background technology]

[0001] The following disclosure relates to vehicle electronic systems that include parking brake equipment. Summary of the Invention

[0002] A traditional handbrake is very simple; in fact, by lifting a lever, two cables are pulled on the rear brake, causing the brake pads (or shoes) to close against the disc (or drum), holding the rear wheel firmly in place.

[0003] An electronic parking brake (EPB) replaces this mechanical system with an electrical one.

[0004] EPB systems offer other features such as automatic release of the parking brake, re-clamping with additional force when a vehicle is detected, or a hill-hold function (applying the brakes to prevent rollback when pulling away on a grade).

[0005] A standard EPB operates in an open loop and applies braking force to the vehicle when requested by the driver by manual or automatic command.

[0006] This use in open loop encounters several limitations that must be overcome with respect to the EPB design system to ensure its correct operation in all circumstances.

[0007] One of the phenomena that can occur at the contact point between the brake pad and the disc is a change in pad thickness due to material swelling (eg due to temperature cooling).

[0008] Temperature changes in the brake pads cause force losses after EPB application due to variations in pad and rotor thickness (up to several hundred microns in the same case).

[0009] This is a well-known phenomenon that needs to be compensated for to ensure the vehicle remains stationary after the EPB is applied.

[0010] The problem becomes even greater when the vehicle is parked on an inclined road.

[0011] The open loop strategy employed in standard EPBs does not allow for real-time recovery of EPB force loss or adjustment of braking force to vehicle weight variations.

[0012] The strategy typically applied to standard EPBs is periodic force reapplication, often combined with an indication of vehicle tilt on the road.

[0013] Because the open loop strategy cannot measure the variations that occur in the caliper, EPB manufacturers are often forced to design systems that overestimate both the size and the number of re-clamps (and applied forces).

[0014] These large forces, when further repeated, can result in weakening of the brake pads and materials, which can damage the brake pads in the long term.

[0015] Therefore, the technical problem described in this disclosure is to remove such limitations.

[0016] The technical problem of the present disclosure is achieved by providing a vehicle electronics system including a parking brake device including a brake element including either a brake pad or a brake shoe, wherein the brake element includes an electric circuit with one or more sensors for real-time detection of signals related to temperature and / or normal force and / or shear force, and has electric terminals arranged in zones for collecting signals from the brake element, the vehicle electronics system further comprising an actuator of the brake element, a controller that sends a braking force command to the actuator, and adjusting means that drives the controller, the adjusting means including a closed braking force adjusting loop that includes a reference braking force and / or torque generator, the closed braking force adjusting loop being in communication with a sensor to obtain at least one of the temperature and / or normal force and / or shear force measurements.

[0017] In one embodiment, the vehicle electronics system including the parking brake equipment further comprises an accelerometer and / or an inclinometer, and the closed regulation loop of the braking force is in communication with and obtains measurements from the accelerometer and / or the inclinometer.

[0018] The accelerometers and / or inclinometers may be mounted on the vehicle, or more specifically on the braking elements.

[0019] In one embodiment, the closed regulation loop of the braking force further comprises a node comparator of the measured values ​​of the normal force and / or shear force and / or torque values ​​derived therefrom with a reference value of the braking force and / or torque.

[0020] In one embodiment, the reference values ​​for braking force and / or torque are fixed.

[0021] In one embodiment, the braking force and / or torque reference values ​​are variable.

[0022] In one embodiment, the reference value of braking force and / or torque is determined by obtained measurements of at least one of temperature and / or normal force and / or shear force and / or torque measurements derived therefrom.

[0023] In one embodiment, the braking force and / or torque reference values ​​are further determined by the acquired measurements of an accelerometer and / or an inclinometer.

[0024] In one embodiment, the braking force and / or torque reference values ​​are determined solely by measurements taken from the temperature sensor.

[0025] The present disclosure also provides a method of clamping the wheels of a vehicle using the above-described vehicle electronic system including parking brake equipment, wherein braking force fluctuations are compensated for as follows. - at least one of the acquired temperature and / or normal and / or shear force measurements is processed to determine a reference braking force and / or torque value and / or at least one normal and / or shear force measurement is processed in combination with either the reference braking force and / or torque value or a fixed reference braking force and / or torque value to drive the controller; The controller sends braking force and / or torque commands to the actuator.

[0026] In one embodiment, the acquired measurements of the accelerometer and / or inclinometer are further processed by a reference braking force and / or torque generator to determine a reference braking force and / or torque value.

[0027] In one embodiment, the measurements are processed in real time.

[0028] In one embodiment, a failure of the parking brake equipment, either in application or in deactivation, is detected by a consistency check between the reference braking force value and the measured value.

[0029] Various embodiments are illustrated in the accompanying drawings for purposes of illustration and should not be construed as limiting the scope of the present disclosure in any way. Various features of different disclosed embodiments can be combined to form additional embodiments that are part of this disclosure. [Brief explanation of the drawings]

[0030] [Figure 1] 1 shows a schematic layout of a vehicle electronic system including a parking brake device according to a first embodiment adapted to compensate for braking force variations due to brake cooling; [Figure 2] 2 illustrates a schematic representation of the total clamping force required on a sloped road to prevent skidding of a vehicle equipped with a vehicle electronics system including the parking brake device of FIG. 1; [Figure 3] 10 shows a schematic layout of a vehicle electronic system including parking brake equipment according to a second embodiment adapted to compensate for both braking force variations due to brake cooling and increased load on the brakes due to external causes; [Figure 4] 10 shows a schematic layout of a vehicle electronic system including parking brake equipment according to a third embodiment adapted to compensate for both braking force variations due to brake cooling and increased load on the brakes due to external causes; [Figure 5a] 5A and 5B schematically illustrate the total clamping force required to prevent slippage of a vehicle equipped with a vehicle electronics system including the parking brake equipment system of FIG. 3 or FIG. 4, respectively, due to weight fluctuations (e.g., a passenger getting into a parked vehicle on a sloping road) and external conditions (the vehicle being bumped while parking along a sloping road). [Figure 5b] 5A and 5B schematically illustrate the total clamping force required to prevent slippage of a vehicle equipped with a vehicle electronics system including the parking brake equipment system of FIG. 3 or FIG. 4, respectively, due to weight fluctuations (e.g., a passenger getting into a parked vehicle on a sloping road) and external conditions (the vehicle being bumped while parking along a sloping road). [Figure 6] 10 shows a schematic layout of a vehicle electronic system including parking brake equipment according to a fourth embodiment adapted to enhance reclamping logic with brake element temperature acquisition; [Figure 7]10 shows a schematic layout of a vehicle electronic system including parking brake equipment according to a fifth embodiment adapted to enhance reclamping logic with brake element temperature acquisition; DETAILED DESCRIPTION OF THE INVENTION

[0031] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, like reference numerals generally identify like elements, unless the context dictates otherwise. The exemplary embodiments set forth in the detailed description and drawings are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented herein. The aspects of the present disclosure, as generally described herein and illustrated in the figures, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are expressly contemplated and make a part of this disclosure.

[0032] A vehicle electronic system according to the present invention includes parking brake equipment, such as, but not necessarily, an electronic or electromechanical brake system or a smart caliper brake system.

[0033] For purposes of example and not limitation, the following will refer to an EPB system for a vehicle 6 having brakes 1 with smart brake elements 2 including either brake pads for disc brakes or brake shoes for drum brakes.

[0034] The smart brake element 2 comprises one or more sensors, in particular a temperature sensor 3 and / or a normal force sensor 4 and / or a shear force sensor 5, for real-time detection of signals relating to temperature and / or normal force and / or shear force, and comprises an electrical circuit having electrical terminals arranged in zones for collecting signals from the brake element.

[0035] The EPB system further comprises an actuator 8 of the braking element 2 , a controller 7 for issuing a braking force command to the actuator 8 , and adjusting means 9 , 10 for driving the controller 7 .

[0036] Advantageously, the regulating means 9 comprise a closed regulation loop of the braking force including a reference braking force and / or a torque generator 10 .

[0037] Furthermore, the braking force closed regulation loop is in communication with sensors 3, 4, 5 for obtaining at least one of temperature and / or normal force and / or shear force measurements.

[0038] The electronic parking brake system 1 may further comprise an accelerometer 11 and / or an inclinometer 12 of the vehicle 6 .

[0039] The braking force closed regulation loop 9 in this case also communicates with an accelerometer 11 and / or an inclinometer 12 to obtain measurements therefrom.

[0040] The closed regulation loop 9 of the braking force may further comprise a node comparator 13 which compares the measured values ​​of the normal and / or shear forces and / or torque values ​​derived therefrom with a reference value of the braking force.

[0041] The braking force and / or torque reference values ​​may be fixed or variable.

[0042] The reference braking force and / or torque may be determined by the obtained measurements of temperature and / or normal force and / or shear force.

[0043] The reference values ​​for braking force and / or torque may be determined solely from the measurements taken of the temperature sensor.

[0044] The braking force and / or torque reference values ​​may further be determined by the acquired measurements of the accelerometer 11 and / or the inclinometer 12 .

[0045] In one embodiment, the smart brake element is a sensored brake pad comprising a support plate, a friction pad and an electrical circuit with sensors for real-time detection of signals related to temperature and / or normal and / or shear forces.

[0046] The normal and shear force sensors may include piezoelectric ceramic sensors, but may alternatively be capacitive or piezoresistive sensors.

[0047] The temperature sensor may be a thermistor, for example, a PT1000, a PT200, or a PT100.

[0048] The electrical circuit has electrical terminals located in the zones for collecting signals from the brake pads.

[0049] The support plate is preferably, but not necessarily, made of metal and directly supports the electrical circuitry.

[0050] The friction pad is applied to the side of the support plate on which the electrical circuit resides, so that the electrical circuit is integrated between the support plate and the friction pad.

[0051] In some embodiments, the smart brake pad is primarily comprised of four distinct parts: a metal backing plate, a sensing layer (electronic circuitry, interconnect media, and integrated force and temperature sensors) on the backplate, an optional damping layer, and a friction material layer.

[0052] In use, the smart brake element can transmit an electrical signal proportional to the detected temperature of the brake element and / or the braking force applied to the brake element as a result of contact with the element being braked (disc or drum).

[0053] The shear sensor in one embodiment may be made of a piezoelectric ceramic material, preferably having a thickness of at least 0.2 mm and an operating temperature greater than 200°C.

[0054] The temperature sensor in one embodiment may preferably have a usable range of -50 to 600°C.

[0055] A temperature sensor may also be used to measure the temperature of the smart brake element and compensate for signal changes as a function of temperature.

[0056] The normal force sensor in one embodiment may preferably comprise a piezoelectric ceramic material having a thickness of at least 0.2 mm and a Curie temperature greater than 200°C.

[0057] The electrical circuit in which the sensors are mounted may be electrically isolated and have branches suitably shaped to place the sensors at distinct locations on the support plate.

[0058] The EPB system can be used to estimate and compensate for both braking force variations due to brake cooling and increased load on the brakes due to external causes.

[0059] The embodiment shown in FIG. 1 makes it possible to compensate for braking force fluctuations due to brake cooling, and for this purpose it requires the measurement of normal and / or shear forces and / or torque values ​​derived therefrom through normal force sensor 4 and / or shear force sensor 5.

[0060] The EPB system can be switched on either automatically or manually by the driver 14 and a fixed braking force and / or torque value is generated by the reference force / torque generator 10 and sent to the node comparator 13.

[0061] The normal force sensor 4 and / or shear force sensor 5 directly measure the normal and / or shear forces. This measurement is provided as feedback to the node comparator 13, which then compares it with a fixed reference braking force and / or torque value and accordingly produces an error signal which is automatically sent to the controller 7 which generates a braking force command which is sent to the actuator 8 of the smart brake element 2.

[0062] This closed-loop control allows for adjusting the braking force fluctuations in real time, for example to compensate for a reduction in the thickness of the smart brake element 2 (expansion phenomenon).

[0063] In practice, reclamping using normal force feedback can be used to compensate for the reduction in thickness of the smart brake element 2 due to temperature.

[0064] First, the clamping force is applied at a high temperature, then the applied braking force tends to decrease due to the reduction in material of the smart brake element 2 and the expansion of the rotor, so that the braking force tends to decrease to the point where it runs the risk of not being sufficient to guarantee the blocking of the vehicle.

[0065] However, normal and / or shear force fluctuations are detected, and a real-time re-clamping strategy is applied when the measured normal and / or shear forces fall below a defined threshold, ensuring vehicle stationarity. Ultimately, a new correct braking force is implemented, ensuring vehicle stop. Consistency checks between reference and measured values ​​can also be used to detect EPB failures during application or shutdown.

[0066] Figure 2 shows what the conditions are for keeping a vehicle stationary when the vehicle is parked on an inclined road.

[0067] To prevent vehicle slippage, it is necessary to ensure that: Fb-ΔFb≧Fx During the ceremony, Fb is the initial braking force. ΔFb is the variation in braking force caused by a decrease in the temperature of the braking element. Fp is the weight of the vehicle, α is the slope angle of the road, and Fx=Fpsinα.

[0068] The second and third embodiments shown in Figures 3 and 4 are more clearly illustrated with respect to the first embodiment and allow better performance in EPB applications.

[0069] In fact, they make it possible to compensate both for braking force variations due to brake cooling and for increased load on the brakes due to external causes.

[0070] Reference is now made to a second embodiment shown in FIG. 3, which requires measurement of normal force and / or torque and / or temperature provided by the smart braking element 2.

[0071] The normal and / or shear forces and / or temperatures obtained from the sensors 3, 4, 5 are used by the adjusting means 9, which in this case includes a state observer 15, to generate a variable braking force and / or torque reference value required to lock the vehicle, taking into account the effects of variations in the thickness of the brake elements, the vehicle weight, the variability of the external conditions, etc.

[0072] In particular, torque variations measured / estimated through sensors 4, 5 of the smart braking element 2 can also be used for smart reclamping in order to avoid / minimize slip phenomena.

[0073] In one embodiment, the operational steps can be described as follows: -EPB activation automatically or by driver 14 - Estimation of torque fluctuations in the state observer 15 through measurements from the sensors 4 and / or 5 of the smart brake element 2 and generation of a reference braking force and / or torque value (which estimates the torque fluctuations in the EPB-ON state). - Generated adjusted braking force command

[0074] This method uses only torque measurements, but can be improved by combining torque measurements with normal and / or shear force and / or temperature measurements to update the reference braking force and / or torque values.

[0075] The reference braking force and / or torque values ​​thus generated in the state observer 15 can be used as direct inputs to the braking force control loop or can be integrated into an existing reference generator 10 .

[0076] The normal force measurement by the normal force sensor 4 may or may not be used as feedback to close the control loop.

[0077] Consistency checks between the reference and the measurements can also be used to detect faults in the EPB during operation or shutdown.

[0078] FIG. 5a shows what the conditions are for keeping a vehicle stationary when the vehicle is parked on an inclined road and weight fluctuations occur, for example, due to passengers getting into the parked vehicle.

[0079] To prevent vehicle slippage, it is necessary to ensure that: Fb+ΔFb≧Fx+ΔFx=Fpsinα+ΔFpsinα During the ceremony, Fb is the initial braking force. Fp is the vehicle weight. ΔFx is the additional weight. ΔFb is the additional braking force required to keep the vehicle stationary, and α is the slope angle of the road, Fx=Fpsinα.

[0080] Figure 5b shows which conditions are necessary to keep the vehicle stationary depending on the external situation, for example, when the vehicle is parked on an inclined road and a vehicle collision occurs during parking.

[0081] To prevent vehicle slippage, it is necessary to ensure that: Fb+ΔFb≧Fx+ΔFx=Fpsinα+ΔFx Fb is the initial braking force. Fp is the vehicle weight. ΔFx is the additional force generated by the collision. ΔFb is the additional braking force required to keep the vehicle stationary, and α is the slope angle of the road, Fx=Fpsinα.

[0082] In the above example, the angle α can be measured directly using equipment currently used on the vehicle, such as an accelerometer 11 or an inclinometer 12 .

[0083] Reference is now made to a third embodiment shown in FIG. 4 which requires measurements of normal force and / or torque and / or temperature provided by smart braking elements 2 and measurements of vehicle acceleration gradient provided by accelerometers 11 and / or inclinometers 12.

[0084] The only difference with respect to the second embodiment is that additionally, measurements obtained from the accelerometer 11 and / or the inclinometer 12 are used in the state observer 15 to generate the braking force and / or torque reference value required to lock the vehicle, taking into account the effects of variations in the braking elements 2, the vehicle weight, variations in external conditions, etc.

[0085] Again, the reference braking force and / or torque values ​​thus generated in the state observer 15 can be used as direct inputs to the braking force control loop or can be integrated into an existing reference generator 10.

[0086] Again, the normal force measurement by the normal force sensor 4 may or may not be used as feedback to close the control loop.

[0087] Again, consistency checks between the reference and the measurements can be used to detect EPB activation or deactivation failures.

[0088] The fourth and fifth embodiments shown in Figures 6 and 7 refer to another technique for strengthening the reclamping logic.

[0089] In this case, the temperature of the smart brake element 2 is obtained.

[0090] The temperature acquisition has a dual purpose: firstly, it allows to predict the inevitable decrease in normal force due to expansion variations of the friction material, and secondly, it can provide compensation for the operation of the normal force sensor 4.

[0091] Now, reference is made to FIG.

[0092] Direct measurement of the temperature of the smart brake element 2 can be integrated into existing models, reducing errors and false triggers.

[0093] In this case, a state observer may not be necessary.

[0094] In this case, no node comparator is needed.

[0095] In one embodiment, the operational steps can be described as follows: -EPB activation automatically or by driver 14 - Measuring the temperature from the temperature sensor 3 of the smart brake element 2 and generating a reference braking force and / or torque value in an existing reference generator 10 based solely on the measured temperature. A reference braking force and / or torque value that is sent to the controller 7 to generate the braking force command that is sent to the actuator 8.

[0096] Now, reference is made to FIG.

[0097] Direct measurement of the temperature of the smart brake element 2 can be integrated into existing models, reducing errors and false triggers.

[0098] Also, in this case, a state observer may not be necessary.

[0099] In this case, the node comparator 13 is necessary.

[0100] In one embodiment, the operational steps can be described as follows: -EPB activation automatically or by driver 14 - measuring the temperature from the temperature sensor 3 of the smart brake element 2 and generating a reference braking force and / or torque value in the existing reference generator 10 based solely on the measured temperature; - measuring normal and / or shear forces (torque) from the sensors 4, 5 of the smart brake element 2. Comparison in the node comparator 13 of the reference braking force and / or torque values ​​with the normal and / or shear (or torque) force measurements coming from the sensors 4, 5. The output of the comparison is sent to the controller 7 to generate a braking force command that is sent to the actuator 8.

[0101] Thus, in this case the measured normal and / or shear forces and / or torques are used as feedback to close the control loop.

[0102] Consistency checks between the reference and the measurements can also be used to detect faults in the EPB during operation or shutdown.

[0103] Generally speaking, in a method of clamping a vehicle wheel using a vehicle electronic system according to the present disclosure, braking force variations are compensated for as follows. the acquired temperature and / or normal and / or shear force measurements are processed to determine a reference braking force value and / or at least one normal and / or shear force measurement is processed in combination with either a reference braking force and / or torque value or a fixed reference braking force and / or torque value to drive the controller 7; The controller 7 sends braking force commands to the actuator 8 .

[0104] Of course, the measurements of the accelerometer 11 and / or inclinometer 12 may be further processed to determine reference braking force and / or torque values.

[0105] The measurements are preferably processed in real time.

[0106] In addition to what has been described, modifications and variations are of course possible. The vehicle electronic system including the parking brake device so conceived is susceptible to numerous modifications and variations, all of which fall within the scope of the inventive concept. Moreover, all details may be substituted with other technically equivalent elements. In fact, the materials and systems used may be any according to the needs and the state of the art. The following is a summary of the claims as originally filed: [1] A vehicle electronics system including a parking brake device comprising a brake element (2) comprising either a brake pad or a brake shoe, the brake element (2) including an electric circuit with one or more sensors (3, 4, 5) for real-time detection of signals related to temperature and / or normal force and / or shear force, and having electric terminals arranged in zones for collecting the signals from the brake element (2), the vehicle electronics system further comprising an actuator (8) of the brake element (2), a controller (7) for sending a braking force command to the actuator (8), and regulating means (9, 10) for driving the controller (7), the regulating means (9, 10) including a closed braking force regulation loop including a reference braking force and / or torque generator (10) and / or a state observer (15), the closed braking force regulation loop communicating with the sensors (3, 4, 5) to obtain at least one of the temperature and / or normal force and / or shear force measurements. [2] The vehicle electronic system including the parking brake device according to [1], further comprising an accelerometer (11) and / or an inclinometer (12), wherein the closed regulation loop of the braking force communicates with the accelerometer (11) and / or the inclinometer (12) and obtains measurements therefrom. [3] The vehicle electronic system including the parking brake device according to [1], wherein the closed regulation loop of the braking force further includes a node comparator (13) between a measured value of normal force and / or shear force and / or a torque value derived therefrom and a reference value of the braking force and / or torque. [4] A vehicle electronic system including the parking brake device according to any one of [1] to [3], wherein the reference values ​​of braking force and / or torque are fixed. [5] A vehicle electronic system including the parking brake device according to any one of [1] to [4], wherein the reference values ​​of braking force and / or torque are variable. [6] A vehicle electronic system including the parking brake device according to any one of [1] to [5], wherein the state observer (15) generates the reference value of braking force and / or torque. [7] A vehicle electronic system including a parking brake device according to any one of [1] to [6], wherein the reference value of braking force and / or torque is determined by the acquired measurement value of at least one of temperature and / or normal force and / or shear force and / or torque value derived therefrom. [8] A vehicle electronic system including the parking brake device described in [7], wherein the reference values ​​of braking force and / or torque are further determined by the measurements obtained from the accelerometer (11) and / or inclinometer (12). [9] A vehicle electronic system including a parking brake device according to any one of [1] to [8], wherein the reference values ​​of braking force and / or torque are determined solely by the measurements obtained by the temperature sensor (3).

[10] A vehicle electronic system including the parking brake device according to any one of [1] to [9], wherein the sensor is a piezoelectric ceramic sensor.

[11] A vehicle including a vehicle electronic system including the parking brake device according to any one of [1] to

[10] .

[12] A method for clamping a wheel of a vehicle using a vehicle electronic system including the parking brake device according to any one of [1] to

[11] , wherein the braking force fluctuation is: - at least one of the acquired temperature and / or normal and / or shear force measurements is processed to determine a reference braking force and / or torque value, and / or the at least one normal and / or shear force measurement is processed in combination with either the reference braking force and / or torque value or a fixed reference braking force and / or torque value to drive the controller (7); and - the controller (7) sends a braking force command to the actuator (8).

[13] The method of

[12] , wherein the acquired measurements of the accelerometer (11) and / or inclinometer (12) are further processed by the reference braking force and / or torque generator (10) to determine the reference braking force and / or torque values.

[14] The method of

[12] or

[13] , wherein the measurements are processed in real time.

[15] The method according to any one of

[12] to

[14] , wherein a failure of the parking brake equipment during application or deactivation is detected by a consistency check between the reference braking force and / or torque value and the measured value.

Claims

1. 1. A vehicle electronic system including a parking brake device comprising a brake element (2) comprising either a brake pad or a brake shoe, the brake element (2) comprising an electric circuit with one or more sensors (3, 4, 5) for real-time detection of signals related to temperature and / or normal force and / or shear force, and having electric terminals arranged in zones for collecting the signals from the brake element (2), the vehicle electronic system further comprising an actuator (8) of the brake element (2), a controller (7) for sending a braking force command to the actuator (8), and regulating means (9, 10) for driving the controller (7), the regulating means (9, 10) comprising a reference braking force and / or torque generator (10) or a closed braking force regulation loop comprising the reference braking force and / or torque generator (10) and a state observer (15), the closed braking force regulation loop being in communication with the sensors (3, 4, 5) to obtain at least one of temperature and / or normal force and / or shear force measurements, 1. A vehicle electronic system including a parking brake device, wherein a reference value of the braking force and / or torque is determined by the acquired measurements of at least one of temperature and / or normal force and / or shear force and / or torque values ​​derived therefrom, or wherein the reference value of the braking force and / or torque is determined solely by the acquired measurements of a temperature sensor (3).

2. 2. The vehicle electronic system including the parking brake equipment of claim 1, further comprising an accelerometer (11) and / or an inclinometer (12), and the closed regulation loop of the braking force is in communication with and obtains measurements from the accelerometer (11) and / or the inclinometer (12).

3. 2. The vehicle electronic system including a parking brake device according to claim 1, wherein the closed regulation loop of the braking force further comprises a node comparator (13) of a measured value of a normal force and / or a shear force and / or a torque value derived therefrom with a reference value of the braking force and / or torque.

4. A vehicle electronic system including a parking brake device according to any one of claims 1 to 3, wherein the state observer (15) generates the reference values ​​of braking force and / or torque.

5. 5. A vehicle electronic system including a parking brake device according to claim 2, wherein the reference values ​​of braking force and / or torque are further determined by the obtained measurements of an accelerometer (11) and / or an inclinometer (12).

6. A vehicle electronic system including a parking brake device according to any one of claims 1 to 5, wherein the sensor is a piezoelectric ceramic sensor.

7. A vehicle including a vehicle electronic system including a parking brake device according to any one of claims 1 to 6.

8. A method for clamping wheels of a vehicle using a vehicle electronic system including a parking brake device according to any one of claims 1 to 6, wherein the braking force fluctuations are: - at least one of the acquired temperature and / or normal and / or shear force measurements is processed to determine a reference braking force and / or torque value, and / or said at least one normal and / or shear force measurement is processed in combination with either said reference braking force and / or torque value or a fixed reference braking force and / or torque value to drive said controller (7); and - the controller (7) sends a braking force command to the actuator (8).

9. The method described in claim 8, wherein the acquired measurements of the accelerometer (11) and / or inclinometer (12) are further processed by the reference braking force and / or torque generator (10) to determine the reference braking force and / or torque values.

10. 10. The method of claim 8 or 9, wherein the measurements are processed in real time.

11. A method according to any one of claims 8 to 10, wherein a fault in the parking brake equipment during application or deactivation is detected by a consistency check between the reference braking force and / or torque values ​​and the measured values.

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