Control method, vehicular electromechanical brake system and vehicle

Abstract

The present invention relates to a compact and optimised solution for controlling a tribological pair intended to provide vehicle braking, so that so that the tribological pair is moved together or apart by means of threaded components associated with a compact mechanical arrangement, which allow precise control of braking and spacing between the elements of the tribological pair, such as brake pads and brake discs, also allowing the use of this braking for the parking brake, thereby eliminating the need for additional parts. The present invention pertains to the fields of tribology and mechanical, electrical and electronic engineering, and to the automotive sector.

Description

CONTROL PROCESS, VEHICLE ELECTROMECHANICAL BRAKING SYSTEM AND VEHICLE Field of Invention

[0001] The present invention describes a compact and optimized solution for controlling a tribological pair intended to promote vehicle braking, such that the approach or separation movement between the tribological pair is achieved by threaded components associated with a compact mechanical arrangement, which allows for quick and powerful control of braking and spacing between the elements of the tribological pair, such as brake pads and brake disc, enabling the use of this same arrangement for both the service brake and the parking brake, eliminating the need for additional parts. The present invention falls within the fields of tribology and mechanical, electrical, and electronic engineering, as well as the automotive sector. Background of the Invention

[0002] Tribological pairs are formed by at least two elements that exhibit relative motion to or from each other, causing friction. In the automotive sector, the friction between two elements of a tribological pair, such as brake pads and discs, is widely used for vehicle braking.

[0003] The brake is one of the critical components for ensuring vehicle safety, and therefore carries a very high level of responsibility. Its components must be designed to withstand severe physical and chemical stresses arising from inclement weather, water, mud, dirt, and other factors. Furthermore, it is subject to significant fatigue due to numerous operating cycles and the various temperature variations experienced by the brakes, given that friction between their elements produces heat.

[0004] Another complication for vehicle braking systems is the limited space available for their components, requiring the mechanical arrangement to be as small as possible to meet the mechanical demands described above while fitting into a confined space.

[0005] Prior art vehicle braking systems also include a complementary mechanical arrangement called a parking brake, which is designed to brake the vehicle while it is not in use, parked. The need for a dedicated complementary arrangement to provide the parking brake is a complication of the prior art due to limited space. Furthermore, the increased number of brake components also increases the time and cost of manufacturing and maintaining the brakes.

[0006] It should be noted that commercial vehicles usually use pneumatic brakes, where the parking brake function is performed by the brake chamber instead of the brake caliper. Therefore, brake chambers with parking brakes require more space to be accommodated in the vehicle. Furthermore, this type of parking brake provides a single force when applied.

[0007] Thus, it is a technical requirement to have a mechanical arrangement for vehicle brakes that is compact and optimized, occupying a reduced space, but meeting all the severity of the mechanical demands to which the brake is subjected.

[0008] The brake response time should be as short as possible once applied to ensure braking efficiency and safety. Therefore, it is also desirable for the braking system to act precisely and quickly, while also guaranteeing the delivery of high braking force.

[0009] It is also a requirement of the technology to provide a parking brake that does not burden the available space, costs, and time of manufacturing and maintaining the vehicle's brakes, losses that result from the use of a supplementary parking brake mechanism.

[0010] As an example, document US20070068748A1 discloses a parking brake that has an electric motor and sun and planetary gears, a shaft equipped with a spindle and a nut, which is screwed / unscrewed by the spindle and moves inside a piston for parking or service brake function. When the nut reaches the bottom of the piston, the piston is mechanically locked in position. Thus, this locking of the system depends on the outer housing corresponding to the piston that houses the spindle and the nut, that is, An additional component for locking, unlike the present invention. Furthermore, the brake in US6536561 B1 features a hydraulic service brake, while the parking brake is applied via a spindle. Thus, in US6536561 B1, the parking and service brakes utilize distinct mechanisms, not to be confused with the present invention.

[0011] US patent 6536561 B1 discloses an electromechanical brake having an electric motor, two planetary gears that drive a threaded gear, and an electromagnetic device that locks one of the planetary gears. The threaded gear consists of a spindle, a nut, and a thread. When the mechanism is used as a parking brake, both planetary gears are switched without current, locking the planetary gear to maintain braking force, thus locking the mechanism. Similar to the solution in US20070068748A1, the brake in US6536561 B1 adds an additional component, the electromagnetic device, to allow the brake to be used as a parking brake in addition to relying on the locking of the planetary gear.

[0012] Document CN117515068A presents an electromechanical device for disc brakes, which has an electric motor coupled to a coaxial reducer formed by planetary gears associated with an output shaft, which is connected to a spindle. This spindle is unscrewed from inside a sleeve / cylinder to bring the brake pads closer to the disc, effecting braking. Thus, the mechanism has a single spindle for cylinder movement. Additionally, a brake locking mechanism is added for parking. This mechanism acts on a motor input shaft, using an electromechanical assembly, such as a one-way clutch, or an electromagnetic device, for example, a coil. Therefore, although the advance and retraction of the brake pad towards the disc are performed by screwing the spindle for service and parking brakes, it is only locked by the addition of the locking mechanism, and should not be confused with the present invention.

[0013] US patent 4804073A describes a disc brake operated by hydraulic pressure or an electric motor. In the second option, the system features a... A planetary gear set is connected to the motor shaft via a sun gear. Additionally, there is a spindle supported on the piston connected to the pad, so that the piston is displaced for the brake to act as a service and parking brake, while the spindle does not move axially. However, even though US4804073A describes the possibility of using the same mechanism for both service and parking brakes, the descriptions are superficial, without allowing an understanding of how the spindle and piston can be locked for use as a parking brake.

[0014] In this sense, the conventional solution of the technique, as seen in the background described above, adds a device intended for locking the brake in the parking function, considering that there is a dilemma as a compromise relationship to dimension the brake with parking and service functions, in which the optimization of one of the functions entails disadvantages in the other and vice versa.

[0015] In the search for the state of the art in scientific and patent literature, no precedents were found that would solve all the problems of the technique detailed above. Therefore, the technique lacks a solution that allows, in a compact, efficient and highly reliable way, the activation of a vehicle's brakes through a compact and optimized mechanical arrangement, also enabling the activation of the parking brake without requiring additional mechanisms. Summary of the invention:

[0016] Thus, the present invention solves all the problems of the prior art mentioned above. This is done by means of a compact and optimized mechanical arrangement, moving it quickly and precisely, ensuring the delivery of sufficient and satisfactory braking force.

[0017] The aforementioned solution is achieved by means of a threaded pair for moving the friction element of the tribological pair. For the purposes of the present invention, the friction element of a tribological pair for vehicle brakes is at least one of the following: brake pad, brake lining, brake shoe, or an equivalent.

[0018] The threaded pair of the present invention is designed in such a way that the friction between the two threaded components keeps the assembly in the braking position if there is no effort to return it to the rest position.

[0019] For the purposes of the present invention, the brake is in the rest position when the brake is not being applied, that is, when no braking action is being requested.

[0020] Thus, another advantage of the present invention is the parking brake function attributed to the braking system itself, along with the service brake, without the need for additional components dedicated to this parking function. This is because the parking brake function is achieved through the threaded pair housed in the brake caliper, also called the brake clamp.

[0021] Thus, instead of a brake chamber, the electromechanical brake has an electric motor that actuates the threaded pair that provides the brake locking function in the parking position, and the electric motor also unlocks the brake in the parking position. Consequently, with the same arrangement providing both the service brake and the parking brake, the invention allows for a reduction in the size of the brake system and, consequently, occupies less space in the vehicle.

[0022] Thus, a major advantage of the present invention is the possibility of eliminating supplementary parking brake devices and, consequently, resulting in reduced manufacturing and maintenance time and costs for the mechanical brake arrangement compared to the previous technique. Furthermore, the system arrangement and its control overcome the difficulties of the previous technique in dimensioning the brake for operation as both a service brake and a parking brake.

[0023] In a first object, the present invention presents a process for controlling a vehicle electromechanical brake system, comprising a tribological pair for applying the service brake and parking brake, the process comprising the steps of: approaching or separating elements of the tribological pair by means of a set of threaded components driven by an electric motor, said set of components being comprised within a mechanism of the electromechanical brake system; locking of said mechanism by means of the threaded component assembly itself, in case the parking brake is applied; and unlocking of said mechanism by means of the electric motor in case the parking brake is released.

[0024] In a second object, the present invention presents a vehicle electromechanical braking system, comprising: a tribological pair for applying the service brake and parking brake; an electric motor; a mechanism comprising a set of threaded components actuated by the electric motor to generate an approach or separation between elements of the tribological pair; and a control unit communicating with the electric motor, wherein: if the control unit receives a signal to activate the parking brake, the set of threaded components itself performs a locking of said mechanism; and if the control unit receives a signal to release the parking brake, the electric motor performs an unlocking of said mechanism.

[0025] In a third object, the present invention relates to a vehicle comprising at least one electromechanical braking system comprising parking brake and service brake functions.

[0026] These and other objects of the invention will be immediately appreciated by those skilled in the art and will be described in detail below. Brief Description of the Figures

[0027] The following figures are presented:

[0028] Figure 1 shows a perspective view of an embodiment of the present invention applied to an electrically driven disc brake, defining the electromechanical brake system.

[0029] Figure 2 shows a perspective view of a longitudinal section of the embodiment illustrated in Figure 1, highlighting the axis of the electric motor.

[0030] Figure 3 shows a front view of the section indicated in Figure 2.

[0031] Figure 4 shows another longitudinal cross-sectional view, highlighting one of the spindles (5) driven by the motor.

[0032] Figure 5 shows a front view of the section indicated in Figure 4.

[0033] Figure 6 shows a top view of a longitudinal section of the embodiment illustrated by Figure 1, highlighting the two spindles (5).

[0034] Figure 7 shows a detailed view of the view shown in Figure 6.

[0035] Figure 8 shows the clamping force graph by spindle position, illustrating the performance of the clamping force estimation algorithm.

[0036] Figure 9 illustrates a flowchart outlining the steps of the algorithm for activating the parking brake.

[0037] Figure 10 shows a simulation as a proof of concept of the invention, indicating the clamping force between real and estimated values, with application of the service brake function, followed by application of the parking brake function in the same electromechanical brake system.

[0038] Figure 11 illustrates the priority relationship between the service brake and the parking brake.

[0039] Figure 12 demonstrates a reconfiguration of the parking brake from a clamping force of 65 kN to 85 kN and 90 kN.

[0040] Figure 13 shows a graph illustrating that, after the parking brake is applied, the torque value returns to zero. Detailed Description of the Invention

[0041] The present invention provides an electromechanical brake system for vehicles in general, from light to heavy vehicles, being either a disc brake system or a drum brake system, for application as a service brake and a parking brake.

[0042] These service brake and parking brake functions are integrated into the same electromechanical brake system of the invention, simplifying the manufacturing and assembly of the system, since it eliminates additional components for embedding the parking brake. In one embodiment, the parking brake is independent of the service brake because these functions are performed by distinct algorithms and / or actuation methods. distinct conductors. Furthermore, with the reduction in the number of components, the invention facilitates diagnostics and maintenance on the system for repair, replacement, or reconfiguration.

[0043] With the system calibrated and properly adjusted, compensating for any wear or over-adjustments in the tribological pair's position, the system operates as expected, aiming for safety while driving the vehicle, durability of the system components, and reliability for the operation of the parking and service brakes.

[0044] Additionally, due to the simplified construction of the brake system of the invention compared to the prior art, the objects of the invention apply to vehicles under manufacture or already manufactured, as an upgrade to the brake system, even if the vehicle does not have any previously installed onboard sensors.

[0045] The present invention comprises at least one brake actuation device (3) associated with an amplification arrangement (4) of the actuation received from the device (3), said amplification arrangement (4) being associated with a set of threaded components, which are associated with the friction element (1) of the tribological pair.

[0046] For the purposes of the present invention, the tribological pair is formed by a first friction element (1) that is moved towards a second element (2) of the tribological pair. In one embodiment, the tribological pair of the present invention is at least one of: brake pad and disc; brake drum and lining; or brake shoe and railway wheel, or equivalents, wherein the first friction element of the tribological pair is at least one of: brake pads; brake lining; brake shoe or equivalents. In one embodiment, the inverted arrangement also applies to the invention, wherein the second element (2) of the tribological pair is moved towards the first friction element (1).

[0047] For the purposes of the present invention, the brake is in the rest position when the brake is not being applied, that is, when no braking action is being requested, whether from the service brake or the parking brake. In one embodiment of the brake in the reinforcement position, there is a predefined spacing or clearance between the elements of the tribological pair, this distance being... Predefined based on safety and braking efficiency through the shortest response time, in addition to preventing an effect known as drag.

[0048] In one embodiment, the forward movement of the friction element of the tribological pair promoted by the device (3) occurs when braking is activated, in order to promote contact between the friction element (1) of the tribological pair and the second element (2) of the tribological pair. Consequently, the backward movement of the friction element promoted by the device (3) generates a spacing between said friction element (1) and the second element (2) of the tribological pair, where the brake moves to the rest position.

[0049] The device (3) is intended to receive a braking signal from a vehicle user and / or a control center of an autonomous vehicle and / or a control center of a vehicle with intelligent / automatic brakes. In one embodiment, the control center is a control unit embedded in the vehicle. In one embodiment, the control unit is connected to the device (3) of the electromechanical brake system.

[0050] Next, the device (3) sends a drive command to the amplifier (4). This device (3) is understood in the following descriptions as an electric motor without restriction of the scope of the invention as to model, current and rated voltage, power, etc.

[0051] The amplifying arrangement (4) is intended to receive the drive command from the device (3), amplifies the torque supplied by this command, and transmits it amplified to the set of threaded components. In one embodiment, the amplifying arrangement (4) is formed by at least one pair of gears, which amplify the torque supplied by the device (3). In one embodiment, the amplifying arrangement (4) comprises at least one set of planetary gears associated with at least one sun gear. In one embodiment, the amplifying arrangement (4) comprises six planetary gears arranged within a tube with internal teeth, which belongs to the brake system housing, with three planetary gears associated with the output shaft of the device (3), transmitting its movement to the three remaining planetary gears, which transmit the amplified torque to the set of threaded components.

[0052] For the purposes of the present invention, the threaded component assembly consists of at least one cylinder (6) having an internal thread and at least one spindle (5) threaded into the inner part of the cylinder (6). Thus, when the brake is applied, the cylinder (6) rotates, unscrewing the spindle (5) from inside the cylinder (6), increasing the total length of the cylinder (6) + spindle (5) combination, which pushes the friction element (1) against the second element (2) of the tribological pair.

[0053] Furthermore, for the brake to return to the rest position, the cylinder (6) rotates in the opposite direction to the braking, screwing the spindle (5) into the cylinder (1), decreasing the total length of the cylinder (6) + spindle (5) combination, which promotes a spacing between the friction element (1) and the second element (2) of the tribological pair.

[0054] In one embodiment, the end of the cylinder (6) opposite the spindle (5) is fitted with a toothed ring which is coupled to the output of the amplifier arrangement.

[0055] In one embodiment, the end of the spindle (5) opposite the cylinder (6) is provided with a polygonal head, and the friction element (1) comprises at least one polygonal cavity compatible with the geometry of the spindle head (5), locking its rotational movement. Thus, when the cylinder (6) rotates, the spindle (5) is prevented from rotating by the engagement of its polygonal head in the friction element (1), and can only move longitudinally or axially, increasing or decreasing the distance between the friction element (1) and the second element (2) of the tribological pair.

[0056] In another embodiment, the association between the spindle (5) and the friction element (1) is provided with at least one cavity and at least one protrusion equivalent to the cavity, such as a pin, key, screw, groove, protrusion and / or the like, so that the spindle (5) is anchored to the friction element (1), prevented from rotating and only moving longitudinally, moving the friction element (1) along with it. It should be noted that the cavity may be disposed in the friction element (1) and the equivalent protrusion at the end of the spindle (5) or vice versa, so that this variation is not limiting to the scope of the present invention.

[0057] In another implementation, in an application that uses two or more assemblies of threaded components, in which at least one set of threaded components is connected to at least one other set of threaded components, such that this connection promotes the anchoring of the spindles (5), preventing them from rotating, it not being necessary that this anchoring be promoted by association with the friction element (1), such that the friction element (1) is free of cavity and / or protrusion equivalent to the cavity.

[0058] In one embodiment, the present invention comprises two or more sets of threaded components for actuating the brake. In an embodiment with two sets of threaded components, each cylinder (6) is provided with a toothed wheel at its outer end to the spindle (5), so that an additional gear is associated with the output of the amplifying arrangement (4) and coupled to the toothed wheel of each cylinder (6). In this way, the torque coming from the amplifying arrangement (4) is transmitted to both cylinders (6) by means of the additional gear, unscrewing both spindles (5) simultaneously, ensuring synchronism for braking and contributing to the homogeneity of the friction area between the friction element (1) and the second element (2) of the tribological pair.In the opposite direction to braking to release the service or parking brake, the torque is also transmitted to the cylinders (6), threading both spindles (5), returning the friction element (1) to the rest position.

[0059] In another embodiment, the spindle (5) is associated with the amplifying arrangement (4) and the cylinder (6) is associated with the friction element (1). In this embodiment, the end of the spindle (5) is fitted with a toothed wheel, while the end of the cylinder (6) is polygonal, for locking in the friction element (1).

[0060] In one embodiment, in an application using two or more sets of threaded components, at least one set of threaded components has a thread ratio different from at least one other set of threaded components. In this embodiment, the braking pressure is not divided equally, but redistributed in order to provide a better pressure distribution on the friction element, which enables the present invention to prevent uneven wear of the friction element (1). since the movement of the second element (2) of the tribological pair causes a difference in clamping force between each set of threaded components.

[0061] For the purposes of the present invention, the friction between the threaded components prevents the elements of the tribological pair from passively separating from each other. Thus, the locking of the brake system mechanism is performed by the threaded component assembly itself, in the event that the parking brake is applied.

[0062] For the purposes of the present invention, passive clearance is an unwanted and / or involuntary clearance. That is, when the parking brake command is released, the friction between the threaded components keeps the brake engaged, unless there is a new command to return the brake to the rest position.

[0063] In this sense, the invention presents a process for controlling the electromechanical brake system for applying the service brake and parking brake.

[0064] For this purpose, at least one signal is received from the service brake and / or the parking brake, with said signal correlated to data regarding a required mechanical load. Additionally, the process also involves the acquisition of data related to a mechanical load applied by the braking system.

[0065] For the purposes of the present invention, the data related to the applied mechanical load is real and provided by an electronic component connected to the electric motor, such as a frequency inverter or a sensor. In one embodiment, the data related to the applied mechanical load refers to dynamic data of the electric motor, for example, speed and torque. In another embodiment, the data related to the mechanical load refers to specifications of the electric motor, for example, model, electrical power, nominal voltage and current, etc. From the data related to the applied mechanical load (e.g., torque on the motor shaft) and a known equation, the actual clamping force applied by the brake caliper on the brake pad against the brake disc is obtained, in one embodiment of the electromechanical system being a disc brake.

[0066] Furthermore, considering a well-adjusted brake system, that is, calibrated and possibly compensated for due to wear or over-adjustment of the friction element (1), the value of the applied load is obtained by an estimation based on said data. In one embodiment, the data is a motor position, which corresponds to the spindle position (5), for calculating the clamping force applied by the tribological pair or torque supplied by the motor (3).

[0067] In one embodiment, the required mechanical load value is obtained by direct association with the data read related to the required mechanical load. For this purpose, in one embodiment, the data related to the required mechanical load is correlated to the actuation signal. In one embodiment, the actuation signal, whether from the parking brake or service brake, corresponds to a specific required load, for example, torque or clamping force.

[0068] In one embodiment, the service brake is activated by a pedal or other device used while driving the vehicle to decelerate or stop it. In another embodiment, the parking brake is activated by a button, lever, or other device used when the vehicle is stationary to keep it at rest. Thus, although the mechanism is the same for both the parking brake and service brake functions, the algorithms and / or methods of activation differ between these functions.

[0069] If the signal is from the activation of the service brake, the data related to the required load is correlated to the brake pedal travel, for example. In this embodiment, the value of the required mechanical load is expected and linked to the brake pedal travel. In one embodiment, the pedal travel is given as a percentage. Thus, in one embodiment, the torque or clamping force values ​​correspond to certain levels of pedal travel, these correspondences being tabulated or calculated through a function. In one embodiment, these correspondences are stored in a memory accessible to the brake system control unit.

[0070] Even if the signal indicates the parking brake has been engaged, the Data related to the required load is predefined. In one embodiment, the process includes a parking brake configuration step based on static and / or dynamic data, in order to pre-configure the clamping force for the parking brake. In one embodiment, static data is predefined data that has a relationship based on at least one piece of information, characteristic, and / or parameter of the vehicle, for example, model, weight when empty, and dimensions (width, height, and length).

[0071] In heavy vehicles, these adjustments are even more relevant, so the parking brake clamping force is greater than in light or passenger vehicles. In a vehicle embodiment being a semi-trailer, the static data is:

[0072] i. Model: refrigerated truck, tanker, container carrier, car carrier, curtainside, grain carrier, dump truck, tipper, among other models;

[0073] ii. dimensions: maximum width, maximum length and maximum load capacity;

[0074] iii. axle parameters: number of axles, distance between axles, axles with suspension and axles in contact with the ground;

[0075] iv. type of cargo: dry; wet, chemical, flammable, etc.; and

[0076] v. presence of load: loading status and load distribution.

[0077] In one application, dynamic data is read by cameras, radar, LiDAR, speed and acceleration sensors, georeferencing, on-vehicle scales, inclinometers, etc.

[0078] From this, the configuration step adjusts the clamping force required for the parking brake, depending on the number of axles, vehicle model, load weight, and / or whether the vehicle is on an incline or decline, for example.

[0079] Thus, the activation signal is received by a control unit communicating with the electric motor. The control unit maintains the proximity between elements of the tribological pair for braking, due to the parking brake or service brake, as long as the value of the applied load is not exceeded. Equal to the required load. This equality takes into account uncertainties or a specific tolerance range.

[0080] Similarly, the control unit maintains the distance between elements of the tribological pair until the applied load value is zero in case the service brake or parking brake is released, provided that a priority relationship is respected.

[0081] Thus, in order to safely apply the service brake or the parking brake, the process includes an additional selection step between the service brake and the parking brake, based on a priority relationship defined as follows:

[0082] i) priority will be given to the service brake if the mechanical load required for the service brake is greater than or equal to the mechanical load required for the parking brake; and

[0083] ii) priority will be given to the parking brake if the mechanical load required for the service brake is less than the mechanical load required for the parking brake.

[0084] Therefore, in a given configuration where the parking brake is engaged, the applied clamping force increases only if the mechanical load required by the service brake is greater than the mechanical load required for the parking brake. If the mechanical load required by the service brake is less, there is no change in the applied force, maintaining the parking brake force.

[0085] Furthermore, the parking brake is only released when the load applied by the service brake is greater than the load of the parking brake. From this point on, and in the event of the parking brake being released, the unlocking of the mechanism is carried out by means of the electric motor (3) which retracts the spindle (5) to the rest position of the friction element (1).

[0086] Thus, the process involves a stage of relative movement, either approaching or moving away, between the elements of the tribological pair. As described earlier, the movement of at least one of the elements of the tribological pair is achieved through the set of threaded components on both sides. service brake as in the parking brake. This set of threaded components plus the amplifier assembly (4) make up the electromechanical system mechanism, which when activated by the electric motor (3), moves the friction element (1) of the tribological pair.

[0087] When a vehicle user and / or a control center of an autonomous vehicle sends an activation command to the device (3), it will transmit movement to the amplifier arrangement (4), which amplifies the torque received and transmits it to each cylinder (6), unscrewing each spindle (5) from inside the cylinders (6), pushing them together with the friction element (1) against the second element (2) of the tribological pair.

[0088] In other words, the locking of the mechanism in the parking brake is performed by the threaded component assembly itself, which also performs the braking in the service brake. In the parking brake, the spindle (5) together with the cylinder (6) generate a pre-tension that keeps the mechanism locked. Thus, the applied load reaches the required load and the mechanism is locked by the spindle (5) together with the cylinder (6).

[0089] In one embodiment, at least one of the following is predefined: the thread pitch of the pair of threaded components; the thread angle of the pair of threaded components; the thread diameter of the pair of threaded components; the coefficient of friction of the pair of threaded components; or a combination thereof, in order to prevent passive separation from occurring in the parking brake, without impairing the braking of the service brake.

[0090] Additionally, for better fit, accommodation or seating between the threaded components - spindle (5) and cylinder (6) -, the locking stage presents a return movement of the spindle (5), in which the electric motor (3) minimally retracts the spindle (5) in the opposite direction to the braking direction. In one embodiment, this minimum return movement is performed after reaching the required parking force. In one embodiment, the motor (3) retracts a certain number of positions detected by the motor encoder (3). In one embodiment, the minimum return is a retraction sufficient for the self-locking of the spindle.

[0091] For the purposes of the present invention, the minimum motor recoil (3) makes possible the relief of the transmission load and the device (3) within a clearance that the mechanical elements of the arrangement (4) allow. Thus, this relief ensures that no energy is consumed in the device (3) when the parking brake is activated and, therefore, the spindle pretension is maintained.

[0092] After locking with the parking brake applied, the electric motor (3) is deactivated, in a concretization.

[0093] In this embodiment, when the power supply to device (3) ceases, the entire mechanism is maintained in the braking position, preventing passive movement, acting as a parking brake. Thus, device (3) does not consume electrical energy while the brake is in parking mode. When the power supply to device (3) is resumed, by action of an algorithm or user to release the parking brake, device (3) sends a torque opposite to braking to the amplifier arrangement (4) which threads the spindle (5) into the cylinder (6), returning the brake to the rest position.

[0094] This feature is particularly relevant for providing a parking brake without requiring additional mechanical arrangements, since the mechanical arrangement for actuating the service brake itself already provides the parking brake effect when desired.

[0095] Furthermore, the set of threaded components is modular, so the brake system can be reconfigured by replacing the threaded components either for maintenance or to adapt the spindle (5) or cylinder (6), in order to meet a self-locking thread status compared with a coefficient of friction to promote locking.

[0096] The present invention comprises a control unit that receives braking parameters, including movement data from the device (3). The control unit is also responsible for commanding the movement of the device (3), sending forward and backward movement signals, based on the brake activation signal received from the vehicle driver and / or control parameters for autonomous vehicles, but also based on the movement data it receives from the device (3).

[0097] Thus, the present invention presents an electromechanical brake system possessing a tribological pair for applying a service brake and a parking brake. The system has an electric motor and a mechanism provided with the set of threaded components driven by the electric motor (3), as well as the control unit. In one embodiment, the control unit is mounted on the vehicle. In another embodiment, the brake system control unit is connected, either wired or wirelessly, to a vehicle control unit (VCU). This brake system implements the control process described above.

[0098] Thus, the control unit commands the electric motor (3) to perform the parking and service functions, using the same mechanism. For locking, there is an advance movement of at least one of the components of said assembly in a braking direction by means of the electric motor; and a return movement of this component of said assembly, in which the electric motor minimally retracts this component of said assembly in the opposite direction to the braking direction.

[0099] In one embodiment, the brake control system algorithm is able to measure the movement of the device (3) and this movement is converted into the movement distance of the tribological pair friction element. With this data, it is possible to correct its position and compensate for the wear suffered by the tribological pair, maintaining a predefined initial spacing between the friction element and the second element of the tribological pair when the brake is in the rest position. In one embodiment, this device movement parameter (3) can also be used to measure the wear levels of the tribological pair and inform a system user in order to alert the need for maintenance and contribute to the scheduling of preventive maintenance.

[0100] In one embodiment, where the present invention is associated with a vehicle, a calibration step occurs whenever the vehicle is restarted. Thus, if any element of the tribological pair is maintained, the present invention adapts to the new distance measurements as soon as the vehicle is restarted.

[0101] In one embodiment, the present invention comprises a Predefined frequency for executing the calibration step.

[0102] The parameters provided by the control unit of the present invention enable the management of wear on the tribological pair elements. These parameters can be sent, stored, and processed in the cloud and / or in the vehicle itself. The wear level values ​​of the tribological pair can be displayed directly on the vehicle's dashboard and / or on a remote device, such as a smartphone, tablet, or equivalent device, and / or accessed in person or remotely via a computer.

[0103] In one embodiment, the present invention is associated with a traffic management platform, enabling the monitoring of multiple tribological pairs of the same vehicle and / or multiple vehicles. Thus, it is possible to predict when the vehicle will need maintenance and, consequently, schedule it.

[0104] Finally, the present invention also provides a vehicle comprising the electromechanical braking system of the invention provided with parking and service brake functions. The vehicle's braking system(s) are as defined above.

[0105] In one embodiment, the present invention is applied to at least one of the following: a road and / or urban vehicle, such as: a semi-trailer truck; a road implement; a truck; a bus; an automobile; a motorcycle; a CVC; autonomous or driven by a driver, remotely or physically present. In another embodiment, the present invention is applied to the braking system of a railway vehicle. In yet another embodiment, the present invention is applied to the landing gear of an aircraft.

[0106] Thus, the vehicle has at least one axle, each axle of the vehicle comprising electromechanical brake systems provided with at least one operating mode, each electromechanical brake system being configurable as needed. In one embodiment, the vehicle's brake systems are identical. In another embodiment, the brake systems are distinct and configured based on the vehicle's dynamic and static data, as well as brake wear data, to optimize braking and the durability of the friction elements (1).

[0107] In one embodiment, the parking brake force is adjustable by the operator using a lever, regulator, input data, etc. In another embodiment, the force is automatically adjusted by an algorithm monitoring dynamic and static vehicle variables. In yet another embodiment, the force is adjusted by integrating the control unit with the VCU, indicating wheel movement and accelerometer data as feedback when the parking force is inadequate – either too high or too low.

[0108] In addition to the parking brake settings, the configuration is also done based on the operating mode, in which each vehicle system has its own settings.

[0109] i) the two modes - parking brake and service brake;

[0110] ii) parking brake mode only; or

[0111] iii) Service brake mode only.

[0112] Furthermore, in a concrete application, the VCU is able to indicate the activation of certain brake systems in order to achieve more even wear across the brake systems, enabling faster maintenance, such as replacing all brake pads.

[0113] Furthermore, in one implementation, the VCU is capable of indicating variations in the intensity of the clamping force for each brake system. Additionally, the same brake system can be installed on another vehicle, based on the configuration of the parking brake and service brake via the control unit.

[0114] The examples shown here are intended only to illustrate one of the numerous ways of carrying out the invention, without limiting its scope. Example 1 - Optimized Vehicle Brake Control System with Included Parking Brake Function for Brake Pads and Discs

[0115] For the purposes of this example, the friction element of the tribological pair is a brake pad (1), the second element of the tribological pair is a brake disc (2), the device (3) is an electric motor and the amplifying arrangement (4) is a set of planetary gears, as illustrated by figures 1 to 7.

[0116] The present example illustrates an embodiment of the present invention, wherein an electric brake actuation system for commercial vehicles wherein the brake actuation is transmitted by the rotation of the shaft of an electric motor (3) disposed in a plane above the brake clamping, this rotational movement is transmitted by an arrangement of planetary gears to a central gear, which is integral with two gears associated with a nut / bolt system, which convert the rotational movement of the gears into an axial movement of the shafts / bolts (5), thus conducting the actuating force on the brake pads (1).

[0117] The output shaft of the electric motor (device (3)) is connected to the center of an amplifier arrangement (4). Thus, the torque originating from device (3) is amplified by the amplifier arrangement (4) before reaching the threaded component assemblies.

[0118] The amplifier arrangement (4) of the present example consists of three planetary gears inserted into a toothed tube inside the brake system housing and directly connected to three other planetary output gears of the amplifier arrangement (4), also arranged inside the toothed tube.

[0119] The output of the second set of planetary gears is given to an additional gear, central to the second set of planetary gears. This additional gear is coupled to the cylinders (1).

[0120] In the embodiment illustrated by figures 1 to 7, the present invention is represented with two pairs of threaded components, each pair of threaded components being formed by a cylinder (6) with internal thread and a spindle (5) associated with the thread of the cylinder (6).

[0121] Each cylinder (6) is equipped with a toothed wheel at its outer end to the spindle (5), so that the additional gear from the output of the amplifier arrangement (4) is coupled to the toothed wheel of each cylinder (6). In this way, the torque coming from the amplifier arrangement (4) is transmitted to both cylinders (6) by means of the additional gear, unscrewing both spindles (5) simultaneously, ensuring synchronism for braking and contributing to the homogeneity of the friction area between the friction element and the second element of the tribological pair.

[0122] To stop braking, the motor rotates in the opposite direction, screwing the spindle (5) onto the cylinder (6) again.

[0123] The friction of the cylinder thread (6) and spindle (5) is predefined so that this same service brake actuation mechanism can be used as a parking brake for the vehicle. When clamping force is generated by the transmission and the system power is interrupted, an axial force still exists that is not lost over time. This axial force keeps the vehicle in a parked position.

[0124] Thus, the clamping force for parking is parameterized and adjustable. The parameterization is based on the calculation of the spindle thread status (5). For the example, the spindle (5) has a trapezoidal thread instead of being a ball screw, which although it presents a higher efficiency for the service brake due to the larger pitch, impairs the parking brake which would not be able to achieve locking by the spindle (5) with the cylinder (6).

[0125] The status of the self-locking thread is based on a relationship between the diameter and pitch of the spindle. For the diameter, a range of 20 to 30 mm is considered. For the pitch, a range of 2 to 10 mm. These values ​​are illustrative and do not restrict the scope of the invention. With this relationship, the helix angle of the spindle is obtained. From this, the thread status is calculated and compared with a coefficient of friction based on the lubrication conditions of the mechanism, finish, and dimensional accuracy, among other factors.

[0126] From this, the invention achieves the self-locking of the spindle (5) for the parking brake by checking if the thread status is less than the coefficient of friction, also considering a balance between the performance of the parking brake and the service brake.

[0127] Thus, under a simple user command, such as pressing a button, the assembly of the present invention advances and locks the brake. The electrical power to the motor (3) is cut off, keeping the system locked by the friction of the thread of the cylinder (6) and spindle (5) system itself. The angle and / or pitch and / or coefficient of friction of the thread is predefined in order to promote this self-locking effect.

[0128] Thus, a major advantage of the present invention is the possibility of eliminate supplementary devices intended for the parking brake, since the parking brake locking is done through the use of the nut / bolt concept, that is, through the use of the pair of threaded components (cylinder (6) and spindle (5)), using only friction to maintain the locking and in such a way as not to lose the tightness even when the mechanism is de-energized. Example 2 - Estimation of Clamping Force

[0129] Estimating braking force using physical sensors implies significant increases in cost and complexity, involving integration with the braking system and vehicle, and the sensor's sensitivity to temperature, wear, and other external factors.

[0130] For the purposes of the present invention, the estimation occurs indirectly, with high accuracy and robustness, and this estimated information is necessary for the operation of complementary algorithms of the processing unit, such as brake pad wear compensation, braking control strategies and operational diagnostics, thus being a strategic resource within the overall system architecture.

[0131] The encoder position reading or spindle advance stroke is divided into three stages as shown in Figure 8, each with an independent model: the first part is the dead zone, where the estimated force is equal to zero; the second part is the compliance zone, where the system cannot be approximated by a linear response; and the third and final part is the linear zone. Thus, the graph in Figure 8 demonstrates the high accuracy of the model that provides data superimposed on the test data. Example 3 - Parking brake

[0132] The parking brake is a feature built into the brake system mechanism itself, working through the self-locking of the threaded spindle that actuates the brake pads. In other words, the thread is rotated and actuates the pads, creating a pre-tension in the spindle, which maintains the applied load. Thus, the load is released when a slight movement occurs. Engine return.

[0133] Following the steps indicated in Figure 9, the parking brake is engaged, and the brake motor advances in the braking direction until it reaches the required clamping force. The advantage of the invention is that, once the parking brake is applied and the required force is exerted, there is no further energy consumption to keep the motor engaged; therefore, the brake can remain applied with the vehicle switched off. Before switching off the engine, the processing unit provides a command for the motor to return a certain number (X) of positions to relieve the load on the transmission and engine (3) within a clearance allowed by the mechanical elements. This relief ensures that no energy is consumed in the engine (3) when the parking brake is engaged, while still maintaining the spindle preload.

[0134] For this purpose, the self-locking spindle is a common system between the parking brake and the service brake. The service brake is controlled by the brake pedal, while the parking brake is controlled by the parking brake button. Although these controls and actuation methods may be different and independent, the service and parking brake systems share the same mechanism containing the spindle.

[0135] Thus, the service and parking brake controls operate in parallel, so the service brake force should be prioritized when it is greater than the parking brake force. When the service brake force is less, the parking brake is prioritized. For this to happen, the parking brake can only be released if the service brake pedal is pressed with a force greater than or equal to the parking brake force.

[0136] Additionally, the parking function, which keeps the vehicle stationary on an incline or decline, for example, an 18% slope, is adjustable for each situation with higher or lower braking demands.

[0137] Furthermore, the implementation of the parking brake algorithm is based on the clamping force estimator algorithm, that is, on a correlation between clamping force and at least one of the engine's state variables - torque, speed, and position. Thus, the clamping force for the parking brake is... Adjustable according to the vehicle's needs or external conditions. Example 4 - Tests and Simulations

[0138] As validation and proof of concept of the invention, tests and simulations were carried out, as indicated in the graphs in Figures 10 to 13.

[0139] Figure 10 shows actual and estimated values ​​for the clamping force.

[0140] Figure 11 illustrates the priority relationship between the service brake and the parking brake, where the service brake force does not add to the parking brake force. The graph shows the parking brake being applied until a certain clamping force is reached. Then, the pedal was pressed more deeply, but without exceeding the parking brake force. After that, the pedal was pressed more deeply, where the service brake exceeded the parking brake force, as shown by the curve above the plateau, until the pedal was released, at which point the force returned to the parking brake. This priority ensures safety when releasing the parking brake while the service brake is engaged.

[0141] Figure 12 demonstrates a reconfiguration of the parking brake from a clamping force of 65 kN to 85 kN and 90 kN, indicating that the clamping force of the parking brake is adjustable by the control unit.

[0142] Figure 13 shows a graph illustrating that, after the parking brake is applied, the torque value returns to zero, unlike the dynamic torque while the service brake is engaged.

[0143] After the initial oscillations due to the service brake, the parking brake is activated by the engine advancing, followed by a brief retraction until the electric motor is deactivated, at which point the engine torque approaches zero, and there is no further energy consumption to keep the parking brake locked.

[0144] Those skilled in the art will appreciate the knowledge presented here and will be able to reproduce the invention in the forms presented and in other variants and alternatives, covered by the scope of the following claims.

Claims

Claims 1. A vehicle electromechanical brake system control process, comprising a tribological pair for applying a service brake and a parking brake, characterized by comprising the following steps: a. bringing together or separating elements of the tribological pair by means of a set of threaded components driven by an electric motor (3), said set of components being comprised in a mechanism of the electromechanical brake system; b. locking said mechanism by means of the threaded component set itself, in case the parking brake is applied; and c. unlocking said mechanism by means of the electric motor (3) in case the parking brake is released.

2. Process, according to claim 1, characterized in that the electric motor is deactivated by applying the parking brake.

3. Process, according to claim 1, characterized in that the locking step further comprises a return movement of at least one of the components of said assembly, wherein the electric motor minimally retracts said component of said assembly in the opposite direction to a braking direction.

4. Process, according to claim 1, characterized by comprising a parking brake configuration step based on static and / or dynamic data.

5. Process, according to claim 1, characterized by comprising an additional selection step between service brake and parking brake, based on a priority relationship.

6. Process, according to claim 5, characterized in that the aforementioned priority relationship indicates: a. priority of the service brake, if a mechanical load required for the service brake is greater than or equal to a mechanical load required for the parking brake; or b. priority of the parking brake, if the mechanical load required for the service brake is less than the mechanical load required for the parking brake; 7. A vehicle electromechanical braking system, comprising a tribological pair for applying a service brake and a parking brake, characterized by comprising: a. an electric motor; b. a mechanism comprising a set of threaded components actuated by the electric motor to generate an approach or separation between elements of the tribological pair; and c. a control unit communicating with the electric motor, wherein: if the control unit receives a signal to activate the parking brake, the set of threaded components itself locks the said mechanism; and if the control unit receives a signal to release the parking brake, the electric motor unlocks the said mechanism.

8. System, according to claim 7, characterized in that the control unit deactivates the electric motor upon receiving the parking brake activation signal.

9. System, according to claim 7, characterized in that the locking mechanism comprises: a. an advance movement of at least one of the components of said assembly in a braking direction by means of the electric motor; and b. a return movement of this component of said assembly, in which the electric motor minimally retracts this component of said assembly in the opposite direction to the braking direction.

10. Vehicle comprising at least one electromechanical braking system characterized in that the electromechanical braking system comprises parking brake and service brake functions.

11. Vehicle according to claim 10, characterized by comprising at least one axle, wherein each axle of the vehicle comprises electromechanical braking systems provided with at least one mode of operation, each electromechanical braking system being configurable as needed.

12. Vehicle according to claim 11, characterized in that the configuration of the electromechanical brake system comprises: a. parking brake mode and service brake mode; b. parking brake mode; or c. service brake mode.

13. Vehicle, according to claim 11, characterized in that the configuration of the electromechanical brake system is based on static and / or dynamic data.

14. Vehicle according to claim 10, characterized in that the electromechanical braking system is as defined in claim 7.

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