Trailer brake control system

Abstract

A system and method for controlling operation of a trailer brake system associated with a farm vehicle-trailer combination is provided, the system and method comprising: determining a trailer brake temperature; comparing the determined trailer brake temperature to one or more temperature thresholds to determine a temperature level condition for the trailer brake; and controlling the trailer brake system in accordance with the determined temperature level condition.

Description

Technical Field

[0001] This invention relates to a control system for vehicle trailer brakes, and more particularly to a control system for agricultural vehicles (such as tractors). Background Technology

[0002] Many vehicles are equipped with attached trailers for transporting goods and materials. For large-scale use, these trailers may be equipped with trailer braking systems to enable safe control of the trailer and prevent jack-knifing or slippage during braking.

[0003] When the force exerted by the trailer on the tractor (also known as the coupling force) exceeds a certain level, either V-bending or slippage occurs. The coupling force is primarily generated by the trailer's weight and inertia during braking. The first effect of excessive coupling force is that the tractor is over-pushped (hereafter referred to as a push condition), and the vehicle's track guiding forces are overcome. This results in a yaw moment / movement about the tractor's vertical vehicle axis that the wheel-to-ground contact cannot withstand. The tractor then begins to slip.

[0004] Another potential impact is that in the case of a drawbar trailer in which the front wheels are pivotally attached to the trailer chassis, the drawbar may unintentionally pivot relative to the chassis through the connecting force, causing the trailer to behave like a folding knife and deviate from its track.

[0005] These effects are particularly noticeable when the vehicle decelerates without the driver engaging the vehicle's service brakes, and when the continuously variable transmission (CVT) downshifts or when a retarder is used on a truck.

[0006] It is well known that these effects can be reduced by applying the trailer's brakes according to the coupling force, thus stabilizing the vehicle assembly. However, the brakes must be applied appropriately to reduce the coupling force, and over-braking must be avoided to prevent instability of the vehicle assembly, as excessive stretching of the assembly will also exert a yaw moment on the tractor.

[0007] With the introduction of electronic braking systems that allow for independent control of braking force by the driver, input systems have been specifically developed for trucks.

[0008] Therefore, trailers used in conjunction with trucks primarily rely on information from onboard assistance systems (such as electronic trailer suspension, ABS, ESP, and ASR) to determine coupling force. In particular, the trailer suspension helps determine the trailer's weight, and other sensors among these help to fine-tune actuator actuation by determining wheel speed and acceleration.

[0009] When focusing on agricultural vehicle combinations (primarily tractors and agricultural trailers), it's crucial to consider that the aforementioned braking systems are not as common as those used in trucks. In particular, trailers rarely come equipped with onboard assistance systems (such as electronic trailer suspension, ABS, ESP, ASR), making it difficult to determine the coupling force.

[0010] It may be advantageous to monitor the health of trailer braking systems that control braking force independently of the driver input system. One example of such a potential failure is known as "brake fade" caused by overheating of braking components. EP1 441 938B1 recommends installing a brake temperature sensor near the brake disc to determine the temperature of at least the braking components. As mentioned above, trailers towed by agricultural tractors are simple in design and are not equipped with such a sensor.

[0011] Therefore, another objective of this invention is to determine the temperature of the trailer brake based on parameters already installed on the tractor, in order to maintain low cost and reduce complexity.

[0012] Known methods for determining trailer brake temperature use trailer brake signals (or pressure) and the duration of brake actuation generated by the tractor control system. This method is described in EP1 441 938B1. However, in such systems, temperature warnings may occur even when no trailer is in use. Therefore, it is advantageous to be able to determine whether a trailer is connected to the tractor and, more importantly, whether the towed trailer is equipped with a trailer braking system. In agricultural operations, it is common to use trailers (or more often, implements) with wheels fully attached to a three-point linkage but not braked. Therefore, it is inappropriate to detect trailers or implements solely based on the identification of the trailer current supply connector (a standard connection on implements used for supplying light, etc.), because even if a connection to the trailer current supply connector is detected, the implement may not have a trailer braking system.

[0013] Therefore, another objective of the present invention is to generate information / warnings to the driver taking into account the status of the attached implements / trailer.

[0014] Furthermore, if known methods are used to determine trailer brake temperature based on trailer brake signals (or pressure) and the duration of brake actuation (generated by the tractor control system), the temperature determination may be inappropriate because, for agricultural trailers, most of the influencing parameters (such as trailer weight) are unknown.

[0015] Therefore, another objective of the present invention is to improve known methods for determining trailer brake temperature by using other available parameters of the tractor to determine trailer brake temperature more accurately.

[0016] The purpose of this invention is to provide a trailer braking control system that overcomes the problems mentioned above and determines the braking force applied to the trailer. Summary of the Invention

[0017] According to one aspect of the invention, a control system is provided for controlling the operation of a trailer braking system associated with an agricultural vehicle-trailer combination. The control system includes a vehicle control unit and is configured to: determine a trailer brake temperature; compare the determined trailer brake temperature with one or more temperature thresholds to determine a temperature level condition for the trailer brake; generate a trailer braking signal for controlling the trailer braking system based on the determined temperature level condition; and forward the trailer braking signal to the trailer braking control system to control its operation.

[0018] Other aspects of the invention provide a braking system that includes and / or can be controlled by the control system described in the foregoing aspects of the invention.

[0019] Other aspects of the invention provide an agricultural vehicle that can be coupled to a trailer to form a vehicle-trailer combination, and includes and / or can be controlled by the control system as described herein.

[0020] Other aspects of the invention provide a method for controlling the operation of a trailer braking system associated with an agricultural vehicle-trailer combination, comprising: determining a trailer brake temperature; comparing the determined trailer brake temperature with one or more temperature thresholds to determine temperature level conditions for the trailer brake; and controlling the trailer braking system according to the determined temperature level conditions.

[0021] Other advantageous embodiments and features are described herein with reference to the following description and / or the appended claims. Attached Figure Description

[0022] The invention will now be described by way of example only with reference to the accompanying drawings, in which: Figure 1 A schematic side view of a vehicle assembly using the present invention is shown. Figure 2 , Figure 3 , Figure 4 , Figure 5 This is a flowchart illustrating the main processing steps of the method for implementing the present invention. Figure 6a A schematic side view illustrating the combination of force applied using the present invention and a vehicle. Figure 6b This is a characteristic diagram showing the drag force depending on vehicle speed, and Figure 7This is a characteristic diagram showing the result of a method for controlling a trailer brake control signal (TBS) according to the present invention.

[0023] Figure 8 , Figure 9 , Figure 10 This is a flowchart illustrating the processing steps of a method according to other embodiments of the present invention. Figure 11A / Figure 11B It is a description of Figure 5 The flowchart of the processing steps shown is modified, but processing steps of the method according to other embodiments of the present invention are added.

[0024] Figure 12 The trailer braking signal and average coupling force are shown as they change over time.

[0025] Figure 13A, Figure 13B Figure 13C , Figure 13D A simplified representation of a graphical warning message according to another embodiment of the present invention is shown, and

[0026] Figure 14A , Figure 14B This is a feature diagram illustrating the result of a method according to another embodiment of the present invention.

[0027] It should be understood that the term “trailer” as used in this article is similar to the more commonly used terms “accessory” or “implementation” in the context of agricultural vehicles such as tractors. Detailed Implementation

[0028] Figure 1 A vehicle assembly 1 comprising a tractor 10 and a trailer 20 is shown, the trailer being attached to the tractor 10 via a trailer drawbar 21 via a tractor attachment system 11. The tractor 10 includes front wheels 5 and rear wheels 6, which are braked by service brake and parking brake systems, not described in detail below, as are known in the art. For braking the trailer, the trailer braking system 30 primarily includes a trailer brake valve 30a and other valve arrangements, and is configured to forward pneumatic or hydraulic brake signals to the trailer via a standardized trailer control coupling 31. Additional trailer supply couplings 32 are provided to supply air or oil to the trailer brakes. At least the trailer braking system 30 is connected to the trailer braking system 40 using two couplings 31, 32. The braking system 40 is used to actuate the brakes of the wheels 25 of the trailer 20.

[0029] For example, when the driver activates the service brake system and / or parking brake system of the tractor 10 (using the handbrake lever) with the brake pedal (not shown), causing the braking demand to be directly transmitted to the trailer brake system 30 via pressurized fluid (such as air or oil), the trailer brake actuation pressure can be generated by the trailer brake system 30. Alternatively, the trailer brake actuation pressure can be generated independently of direct driver activation, but in response to a trailer brake signal TBS from the electronic vehicle control unit (ECU), also known as electronic trailer braking. The following invention focuses on this type of brake signal generation.

[0030] To provide a control system for the trailer brakes of tractor 10 and trailer 20, an electronic vehicle control unit (ECU) receives parameters and / or sends control signals to various components of tractor 10, including: a transmission 50, used to adjust vehicle speed v or vehicle acceleration α according to driver-required settings, and receiving parameters such as the output speed and direction of rotation of the transmission output shaft and the system pressure of the hydraulic branches of the CVT (continuously variable transmission) 100; a gyroscope 60, used to determine vehicle speed v or vehicle acceleration and / or tilt α. The gyroscope may be part of a satellite-based navigation system; a speed pedal 71 and / or a drive lever 72, used to receive driver input regarding vehicle speed or vehicle acceleration; an acceleration rate input 73, used to adjust the degree of acceleration / deceleration when the drive lever 72 is moved; a clutch pedal 74, used to disconnect transmission 50 from the prime mover (such as an internal combustion engine); and an HMI terminal 75, used to enable the driver to input or display various parameters related to vehicle 10, trailer 10, or vehicle assembly 1. Service brake foot pedal 76, which receives driver input for starting the tractor's service brake. Parking brake switch or parking brake lever 77, which receives driver input for starting the tractor's service brake.

[0031] In summary, the main task of the electronic vehicle control unit (ECU) is to provide a processing method that includes: receiving relevant parameters of the vehicle 10; determining the setting value of the trailer brake signal TBS according to the method described below; and forwarding the trailer brake signal TBS to the trailer brake control system 30 to activate the trailer brake.

[0032] In the illustrated embodiment, the trailer brake signal TBS is represented by the pressure requirement controlling the pneumatic trailer brake system 30. Alternatively, the trailer brake signal TBS can be configured to control a hydraulic braking system, and the trailer brake valve 30a can also be hydraulically actuated. Further alternatively, if a brake-by-wire system is installed on the trailer, the trailer brake signal TBS can be relayed to the trailer brake system by any other means, such as an electronic signal.

[0033] Now, refer to Figure 2 , Figure 3 , Figure 4 , Figure 5 The flowchart describes the method for controlling the trailer braking control system 30.

[0034] This method can be implemented on the electronic vehicle control unit (ECU), or alternatively, it can be part of the trailer braking control system 30 when equipped with a corresponding control unit and interface to receive the parameters mentioned above.

[0035] According to the ongoing method, the electronic vehicle control unit (ECU) iteratively generates a trailer brake signal (TBS) to be forwarded to the trailer valve 30a. The trailer brake signal (TBS) receives different values ​​as described below.

[0036] Electronic vehicle control unit (ECU) performs actions such as Figure 1 The main method M100 is described in the text. For clarity, the main method M100 is described in several sub-procedures, among which... Figure 2 It shows including, for example Figure 3 The subprocess S200 shown is as follows: Figure 4 The subprocess S300 shown and as Figure 5 The main method M100 is shown for subprocess S400. Other subprocesses S500, S600, and S700 are described below.

[0037] Now refer to Figure 2 The electronic vehicle control unit (ECU) initializes the method using step S100. Initialization can be triggered if the ignition is started (ON) and the ECU is powered on. Alternatively, initialization can be triggered if the ECU detects that the trailer 20 is attached to the vehicle 10. This can be determined if a standardized current supply connector (supplying current to the trailer 20 and / or activating the trailer 20's lights or turn indicators) is connected to a receiving connector on the vehicle 10.

[0038] After initialization, if the electronic trailer brake function is activated (ETCV=1), the method performs a check in step S105 and then branches to the subroutines in steps S200 and S300. The electronic trailer brake can be activated when the ignition is started and the electronic vehicle control unit (ECU) is powered on, or initially activated / deactivated by driver input. Alternatively, the electronic trailer brake can be temporarily deactivated by actuation of the service brake or parking brake. Deactivating the trailer brake function results in the parameter ETCV=0.

[0039] In subroutine S200, many prerequisites and startup parameters further performed in method M100 are examined, such as Figure 3As described in the text. The term prerequisites mean that these conditions must be met to generally allow the activation of electronic trailer brakes, while activation parameters are used to determine what event caused the deceleration, and can also establish the degree of deceleration and adjust the trailer brake signal accordingly.

[0040] After starting in S201, step S205 will set the state parameter SP. DL SP AS SP CA SP CC SP REV SP ENG (Re)set to zero. The status parameters will be explained later.

[0041] Typically, this activation check determines the prerequisites for activating the electronic trailer braking function and whether and how the vehicle decelerates, particularly but not exclusively, if this is done using the accelerator pedal 71 or the drive lever 72. Furthermore, this step is used to determine the driver's desired degree of deceleration, also known as the driver's deceleration requirement DD.

[0042] These prerequisites aim to avoid vehicle insecurity caused by electronic trailer braking, and to prevent unintentional or unnecessary electronic trailer braking, which can cause driver discomfort when the auxiliary system engages the trailer brakes when clearly unnecessary. In other words, electronic trailer braking should be disabled when not needed.

[0043] Step S206a involves determining the connecting force F. C, real (See subroutine S300) Is it lower than the set value F? CA,min (For example, -3500 N) (within the negative range) to ensure that trailer 20 significantly pushes tractor 10 (pushing condition) to check the first prerequisite. There is a possibility of a higher coupling force F. C, real (When viewed with a negative sign, it is smaller) but the electronic trailer brake should not be activated. For example, this situation may occur if the implement is initially connected to the tractor, or if it traverses a pothole. If not, the process returns to step S206a via loop L207.

[0044] Step S206a must be considered as a prerequisite that, once this prerequisite is met, the connecting force F... C, real It can take any value, even higher than F, in further processing. CA,min However, it does not stop processing or start it.

[0045] In the next steps, a series of other prerequisites will be checked: Step S210a checks whether the transmission clutch is engaged. This is necessary, for example, when the operator intends to roll the vehicle assembly toward an intersection. This process should not be performed further, as it causes the CVT to disconnect from the wheels on the drive, making it impossible to determine the engagement force based on the CVT parameters. Therefore, if yes, step S210b proceeds to check the next prerequisite; otherwise, step S220, described later, is then performed.

[0046] Step S210a is set after step S206a (when the clutch disengages, the engagement force needs to be detected) to ensure that the start is stopped whenever the clutch disengages subsequently.

[0047] Next, steps S210b and S210c proceed to check two prerequisites in the OR relation, where OR means that one of the two conditions must be met. According to step S210b, the vehicle speed should be v. V >0 kph (or alternatively, v) SET >0 kph), or according to step S210c, the tractor 10 at, for example, -4° α<α CA，max Uphill driving (because the negative sign represents the slope), since both conditions are known to result in a propulsive condition. Alternatively, step S210b could consider the vehicle speed v. V Or vehicle speed setpoint v set A minimum value must be exceeded to avoid starting the electronic trailer at low speeds when the pushing conditions are less severe. When one of these prerequisites is met, the method proceeds to step S220, which will be described later. Otherwise, in step S210d, the next prerequisite is checked.

[0048] Step S210d is provided to prevent the electronic trailer brake from being activated when the trailer is stationary on flat ground (without slope or with a slight slope). Therefore, step S210d checks whether v is satisfied. v =0 kph (or alternatively, v) SET >0 kph) and whether the slope is close to zero. This is especially important when a CVT with so-called “active standstill” control is installed: if the vehicle is slowed to a standstill (0 kph) by the speed pedal 71 or drive lever 72 without engaging the service brake or parking brake, the CVT operates in “active standstill” mode. Under this condition, the electronic vehicle control unit (ECU) provides control over the transmission to maintain the output speed of the transmission (and consequently the wheels) at 0 rpm to compensate for unintentional movement caused by idling oil flow in the hydraulic branches of the CVT (as described in the applicant’s published patent applications EP 1 990 230 and EP 2 935 948). This means that the hydraulic unit is constantly adjusted, which can result in the detection of coupling forces that should not cause the trailer brake to engage.

[0049] In summary, steps S210b, S210c, and S210d are used to allow electronic trailer braking when traveling on flat ground, uphill, or downhill, and when the tractor is stationary on a downhill slope, because a pushing condition may exist. However, starting should be prohibited when standing on an uphill slope or flat ground, as these conditions do not result in a pushing condition.

[0050] When the result of step S210d is YES, loop L210 returns to the state before step 210, where the state parameter SP... CA Keep it at zero.

[0051] Alternatively, other prerequisites indicated by step S210d can be checked, which may lead to further processing in step S220 or cause a return to the loop prior to step 210, where the state parameter SP CA Keep it at zero.

[0052] Figure 3 Other prerequisites not shown in the text may be: CVT switched to "neutral": In this operating state initiated via the HMI terminal, the CVT is brought into a state similar to the clutch engagement described in step S210a, wherein the CVT is disconnected from the wheels in drive, making it impossible to determine the engagement force based on the CVT parameters.

[0053] Condition "EU Braking Test": When the parking brake on the tractor is applied while stationary, the driver activates this condition to suppress the actuation of the trailer brake's service braking function. Due to EU regulations, this test procedure must be performed periodically to check whether the tractor's parking brake system can adequately keep the vehicle assembly stationary (when closed) in the event that the trailer brake may fail due to leakage / malfunction in the trailer braking system (excited by spring load). The electronic trailer brake must be permanently disabled during the test to prevent accidental actuation of the trailer brake.

[0054] Activating the electronic trailer brake function: similar to step S105 (in Figure 3 (In the middle), the electronic trailer braking function (ETCV=1) must be activated.

[0055] Maximum speed requirement: If the vehicle speed exceeds 25 kph. Above a certain speed, the wheels tend to lock up during braking. This can be dangerous, especially at high speeds, so this method is prohibited above a certain speed. The maximum vehicle speed value can be determined by the driver's choice or set based on trailer parameters. For example, if the trailer is equipped with an ABS system, a limit may not be necessary.

[0056] The method uses the following steps to detect how the operator inputs a vehicle deceleration request (without actuating the service brake or parking brake). This is done in initiation branches B211, B212, B213, B214, and B215. Initiation branch B211 begins at step S220, where the actuation via drive lever 72 is checked. If the operator intends to decelerate the vehicle, he pushes drive lever 72 back in the opposite direction as indicated by arrow DR. The request value V is then forwarded to the ECU. DL It is in the negative range, and the parameter V DLminus It is set to 1. If drive lever 72 is released, the vehicle speed remains constant, causing parameter V to remain constant. DLminus It was set to 0.

[0057] If parameter V DLminus If set to 1, this leads to step S225, where the state parameter SP... DL It is set to 1 to indicate the input deceleration via the drive lever 72. The next step is step S226, where the value of the acceleration input 73 is determined. The acceleration input 73 is used to determine the operator input regarding the driver's deceleration requirement DD in response to the operator's input, and therefore provides four setpoints: Level I, Level II, Level III, and Level IV. If the operator adjusts the acceleration input 73 to the state parameter SP... AS When the received value is 1 (Level I), the vehicle's speed decreases at the slowest possible rate, resulting in a low and smooth deceleration. This is achieved in the state parameter SP. AS At Level IV with a receiving value of 4, the vehicle's speed will decrease rapidly and will result in a "sharp" deceleration.

[0058] Alternatively, the drive stick can provide proportional speed control, meaning the acceleration rate depends on the yaw angle or yaw speed. In this case, the acceleration level input 73 may be absent, and the state parameter SP... AS It will be set according to the deflection angle or speed.

[0059] If parameter V DLminus If set to 0, indicating that the vehicle is not decelerating via drive lever 72, then the start branch B212 is executed, where further operator input is checked.

[0060] Therefore, branch B212 branches at branches B213, B214, and B215.

[0061] In step S230, using branch B213, the process checks for cruise control disabling. If so, step S232 checks the deceleration via the speed pedal 71. The speed pedal 71 is pressed by the operator's foot and forwards the speed request to the ECU. This differs from the driver's lever 72 in that the deflection angle is proportional to the requested vehicle speed. In other words, if fully depressed, the requested speed is the maximum vehicle speed, or alternatively, any vehicle speed limit that the driver can set via the HMI terminal 75. For example, if the vehicle is being tracked, the driver can set a lower speed assigned to full pedal depressing to increase pedal resolution and allow for finer control. If the speed pedal 71 is fully released (after any depressing), the requested vehicle speed is 0 kph, meaning the vehicle is decelerating. Therefore, step S232 checks if the pedal mode is activated. If not, pressing the speed pedal 71 will not affect vehicle movement but only regulate engine speed. As a result, loop L233 returns to before step S205.

[0062] Step S234 checks whether the speed pedal 71 is fully released (after being pressed), so that V FP It is set to 0. If not, loop L235 returns to before step S205.

[0063] If so, then step S236 will change the state parameter sp DL Set to zero. Refer to step S225, where parameters are set according to the operation of drive lever 72, and the state parameter sp is... DL Information is typically provided on whether the speed pedal 71 or drive lever 72 indicates deceleration.

[0064] If step S230 indicates that cruise control is initiated, branch B213 proceeds to determine the subsequent conditions present in cruise control mode.

[0065] Therefore, step S240 determines whether the current vehicle speed exceeds the cruise control setpoint.

[0066] This occurs under the first cruise control condition, where the cruise control setpoint is changed by: First, the HMI terminal allows the driver to save setpoints C1 and C2 for different cruise control setpoints. Both values ​​can be pre-selected by pressing buttons assigned to C1 and C2, which can be located near or on the drive lever 72. For example, if C1 is 18 kph for field work and 60 kph for high-speed driving on the road, the driver uses this HMI function to switch between the setpoints used in the field or on the road, for example. The driver initiates the cruise control setpoint by using the drive lever 72. When accelerating or decelerating the vehicle by moving the drive lever 72 forward and backward in the drive direction, cruise control is initiated by briefly moving the drive lever 72 to the right. If no value C1 or C2 has been pre-selected, the current speed is considered the new setpoint value.

[0067] Secondly, the driver can adjust the cruise control setpoint in the HMI terminal 75. If a new setpoint lower than the current vehicle speed is selected, this may also result in significant deceleration.

[0068] Even without a significant reduction in setpoint speed, cruise control mode can still lead to a situation requiring electronic trailer braking, known as second cruise control mode. This can happen if the vehicle combination is traveling in cruise control mode on a flat road and then enters a downhill section. The trailer's weight will then begin to push the tractor, causing the vehicle speed to increase and deviate from the setpoint.

[0069] In summary, step S240 determines the vehicle speed in cruise control mode as V V >f CAv v SET The conditions that change significantly are those at the current vehicle speed v. V With factor f CAv Exceeding the cruise control speed setpoint v SET Time. Factor f CAv This represents a percentage change, such that f CAv =1.05 means the current vehicle speed v v Exceeding the speed setpoint v SET Approximately 5%.

[0070] If condition v is not met V > f CAv v SET Then loop L241 returns to before step S205.

[0071] If condition V is satisfied V >f CAv vSET Then step S242 will be in cruise control mode SP CC The status parameter for activation is set to 1, thereby indicating that the electronic trailer brake is activated based on the conditions in cruise control mode.

[0072] In the first cruise control mode, the degree of deceleration depends on the setting of the acceleration rate input 73. In step S243, which is similar to step S226, the state parameter SP is stored. AS .

[0073] Under the second cruise control condition, the deceleration level does not depend on the acceleration rate input 73 setting. When the setpoint remains unchanged but the vehicle speed increases relative to the setpoint during downhill driving in the second cruise control mode, the state parameter SP... As It can always be set to a single value, such as 2.

[0074] Using branch B214 to check other conditions, the process in branch B214 determines the tractor's reversing. Reversing a tractor or vehicle combination means that the tractor's operation changes from a first (e.g., forward) direction at a predetermined vehicle speed to the opposite direction with the same or pre-selected vehicle speed. Therefore, reversing always results in deceleration, which may cause a pushing condition, necessitating the activation of the electronic trailer brake. Reversing can be initiated via the operator user interface. Then, without further manual intervention, the tractor decelerates, passes a standstill, and changes direction. This function provides comfortable operation, for example, during front loader operation. Reversing of tractor 10 can be initiated via various inputs: When accelerating or decelerating the vehicle by moving the drive lever 72 forward and backward in the driving direction, reversing is initiated by moving the drive lever 72 to the left.

[0075] In addition, a button is provided near the steering wheel, for example, on the indicator stalk, to make the tractor 10 reverse.

[0076] Additionally, the driver can choose whether to provide reverse at the same speed simply by changing direction, or to change direction and decelerate / accelerate to a preset point that can be pre-selected for each direction of travel in the HMI terminal 75. This is advantageous, as drivers may prefer to travel slower when reversing.

[0077] Therefore, following branch B214, the next step is step S250, which checks whether the tractor is reversing. If not, loop L251 returns to before step 205.

[0078] If this condition is met, then in step S252, the state parameter SP... REVIt is set to 1, and since the degree of deceleration depends on the setting of the acceleration input 73, the state parameter SP is stored in step S253. AS .

[0079] Additionally, branch B215 and step S260 monitor the reduction in engine speed. The HMI terminal allows the driver to save setpoints MAX and MIN for different engine speed setpoints. Both values ​​can be selected by pressing buttons assigned to MAX and MIN, which can be located near or on drive lever 72. Alternatively, tractor 10 can be equipped with a manual throttle (not shown) that allows the driver to directly adjust the engine speed via rotary control. Since a significant reduction in engine speed results in deceleration, step S260 monitors Δn. ENG >Δn CAmax The engine speed difference, and if the engine speed decreases by approximately, say, Δn CAmax =200 rpm, then the state parameter SP ENG This is set to 1, thus indicating that the electronic trailer brake should be activated based on a decrease in engine speed. This branch may additionally include determining other state parameters to account for factors dependent on the engine speed difference Δn. ENG The degree of deceleration of the absolute value. Δn ENG The larger the value, the higher the deceleration can be; therefore, for example, Δn... ENG =200 rpm or Δn ENG =400 rpm or Δn ENG =600 rpm, different deceleration state parameter values ​​can exist.

[0080] All startup branches B211, B212, B213, B214, and B215 converge in step S270, wherein, when one of the startup requirements in branches B211 to B215 is met, the state parameter SP... AS It is set to 1, thus indicating that starting is normally enabled, regardless of whether starting is caused by the drive lever 72 or the speed pedal 71 or any other condition.

[0081] Using step S250, the method proceeds to step 120, as follows: Figure 2 As depicted in the text.

[0082] In parallel with step S200, step S300 determines the actual coupling force F by taking into account various driving dynamic parameters. c, actual ,like Figure 4 As depicted in the text.

[0083] refer to Figure 6a Further explanation of the actual connecting force F c, actualThe figure vividly depicts the forces exerted on vehicle assembly 1 (especially tractor 10) under driving conditions where vehicle assembly 1 is traveling uphill and the danger of V-shaped bends is particularly high.

[0084] The balance of forces applied to the tractor 10 is well known in the art and yields the following equation: F TRC = F IN + F H + F AR + F R,RA + F R,FA + F C (E1) in,

[0085] vehicle mass m v It is determined based on existing technology and is not described in detail. The mass m can be determined by considering the empty weight of the tractor plus the additional ballast attached to it. v These values ​​can be stored in the ECU. Alternatively, the mass value can be obtained based on vehicle acceleration or wheel load detection. A method is described in the applicant's published patent application EP2766239.

[0086] This also applies to the determination of vehicle acceleration α, tilt angle α, and velocity v of vehicles described and practiced in this field. These two values ​​can be determined by a gyroscope 60, which may be part of a GPS navigation system.

[0087] Must be based on Figure 6a The effective direction is shown in the diagram; insert the negative or positive sign for the force.

[0088] Similar forces will also occur due to the mass of the trailer and the resistance applied to the trailer itself. However, this method only considers the resultant force exerted by the trailer on the tractor, i.e., the connecting force F. C The main advantage of considering only the parameters applied to the tractor is that the trailer does not need to be equipped with sensors or be considered in detail. As mentioned above, the variety of trailers / implements and their basic technical configurations can hinder detailed consideration of the trailer.

[0089] Due to the main connecting force F C These are parameters used to control the trailer braking system, therefore equation E1 changes to: F C = F TRC – (F IN + F H + F AR + FR,RA + F R,FA ) (E4) The force in parentheses represents the tractor's tractive force F. TRV .

[0090] F TRV =F IN + F H + F AR + F R,RA + F R,FA (E5)

[0091] During operation, the inertial force F can be easily determined using parameters already available on the tractor. IN and downhill force F H air resistance F AR and rolling resistance F R,RA F R,FA The summation becomes the total resistance F. R .

[0092] F TRV =F IN + F H + F R (E6)

[0093] Total resistance F R Taken from Figure 6b The graph shown in the figure has the vertical axis representing the total resistance F. R The horizontal axis represents vehicle speed v. This graph was determined through coasting tests during development and then stored in the ECU for each vehicle series. The graph shown is for vehicles operating on asphalt roads (or on-road terrain). Alternatively, other graphs can be determined for grass, farmland, or gravel tracks, and these graphs can then be taken into account when the vehicle is equipped with a device to detect which terrain it is traveling on. This can be determined by a GPS navigation system that transmits geographic information, for example, if the vehicle is traveling on a public road (asphalt), gravel road, or across any road (which could be grass or farmland).

[0094] For example, in the curve shown, the total resistance F at, for example, 25 kph R Considered to be 2575 N

[0095] Therefore, by using equations E1 and E2 and Figure 6b The graph shown in the figure represents the tractor's traction force F. TRV It can be fully determined using equation E6.

[0096] In order to receive the connecting force F CThe remaining equations are: F C = F TRC - F TRV (E7) As known in the prior art, the traction force of the vehicle-mounted FTRC is determined by measuring the fluid pressure in a hydrostatic-mechanically separated continuously variable transmission (CVT) including a hydraulic drive circuit in which a hydraulic pump supplies pressurized fluid to a hydraulic motor. Details are described in the applicant's published patent application WO2013 / 053645 and will not be elaborated further. Alternatively, any other means may be employed to determine the traction force of the vehicle-mounted FTRC, such as using the torque supplied by the engine to receive traction, as described in US 4,548,079. (See GB11 / 44) Then, the connection force can be received using formula E7.

[0097] Using the equations and forces mentioned above, Figure 4 The method described above. Starting from step 301, as explained above, the first branch B305 determines the traction force F of the vehicle combination in step S335. TRC .

[0098] As explained above, the second branch B310 determines the mass m in step S320. v The acceleration a and tilt α are used to further calculate the inertial force F in step S325. IN And in step 326, the downhill force F is calculated. H .

[0099] In the third branch B315, step S330 determines the velocity v as described above, for reference. Figure 6b In step S331, the total resistance F is further determined. R .

[0100] Then, the second branch B310 and the third branch B315 proceed to step S340 to calculate the tractor force F of the tractor as defined by Equation E6. TRV .

[0101] Finally, the values ​​received in steps S335 and S340 are used to calculate the actual connection force F according to Equation E7. C. actual .

[0102] Alternatively, in Figure 4 The steps shown can be performed one after another, or in any reasonable order.

[0103] refer to Figure 2 Subprocess S300 is continuously performed to transmit the actual connecting force F for further steps.C, actual .

[0104] Figure 2 Method M100 continues further, in step S110 continuously monitoring the state parameter SP. CA This indicates that the driver still needs to request the vehicle to slow down via the speed pedal 71 or the drive lever 72. If the start-up is interrupted and the status parameter SP... CA If the value is changed to zero, loop L211 resets all parameters in step S115 and returns to the beginning.

[0105] Figure 2 Method M100 further continues to step S120, which sets the first interval counter c (also known as the brake interval counter) to zero. Then, in step S121, the first timer value t0 is also set to zero (seconds), and the timer is started. These two parameters are provided to meet the requirements for electronic trailer braking systems under Annex I, No. 2.2.1.19.1 (also known as the “EU Mother Regulation RVBR”) of EU Regulation 2015 / 68 (dated 15 October 2014), which limits the duration of electronically activated trailer braking (without the driver operating the service brake) to a maximum duration of 5 seconds. After this, the trailer brake must be released.

[0106] The time limit is monitored using a first time value t0, while the number of braking intervals is determined using a braking interval counter c. Thus, a braking interval is characterized by the time period during which electronic trailer brake control is activated / started, followed by an optional pause period in which the trailer brakes are not activated. The next braking interval begins when the trailer brakes are reactivated after the pause. Therefore, if the activation requirements described in step 200 are not met and the state parameter SP... CA Returning to zero interrupts the braking interval. This causes a reset of all parameters in step 115, which in turn causes a reset of the first interval counter c and the first timer value t0, which are discussed in detail herein.

[0107] Step S125 checks whether the method is currently being performed in the first braking interval (meaning the time limit has not yet been exceeded) or in a subsequent braking interval.

[0108] If so, then in step S131, set the pilot pressure p. P =P P,0 The pilot pressure depends only on the driver deceleration requirement DD as determined in step S200. Typically, the pilot pressure P... P Increased with higher deceleration requirements: If the deceleration is caused by the operator using the speed pedal 71 (obtain the status parameter SP) DL If =0), then the pilot pressure PP,0 It was set to 70 kPA.

[0109] If the deceleration is caused by the operator using drive lever 72 (obtain state parameter SP) DL If =1), then the pressure level depends on the state parameter SP. AS The provided acceleration rate input setting is 73: For SP AS =1 (acceleration rate input 73 is set to Level I, representing the slowest deceleration), pilot pressure P P,0 It was set to 50 kPA.

[0110] For SP AS =2 (acceleration rate input 73 is set to level II), pilot pressure P P,0 It was set to 70 kPA.

[0111] For SP AS =3 (acceleration rate input 73 is set to level III), pilot pressure P P,0 It was set to 100 kPA.

[0112] For SP AS =4 (acceleration rate input 73 is set to level IV), pilot pressure P P,0 It was set to 150 kPA.

[0113] If the deceleration is caused by cruise control (receiving "Yes" in step S240), then the state parameter SP is obtained in step S242. CC =1, or if the deceleration is caused by the activated reverse mode (receiving "Yes" in step S250) thus obtaining the state parameter SP in step S252. REV If the result is 1, then the same value will be used.

[0114] If the deceleration is caused by a decrease in engine speed in step S260, then "yes" is obtained (and the state parameter SP) ENG If set to 1), then the pilot pressure P P,0 Set to 80 kPA

[0115] In this embodiment, it depends on the state parameter SP. AS The pilot pressure P P,0 The setpoint is shared under different deceleration conditions (state parameter SP). DL SP CA SP CC SP REV SP ENGOne of them is set to 1), but alternatively, each deceleration condition can be defined differently.

[0116] These values ​​are retained in the ECU and are further considered in step S140 as described herein.

[0117] If step S125 indicates that the method is currently being performed in a subsequent braking interval, then step S132 sets the pilot pressure p. P =p P,c The pilot pressure is the trailer pressure signal TBS generated in step S150. The advantage of this is that the pilot pressure p... P It always receives the last value generated in the previous braking interval. This avoids trailer brake signal spikes between braking intervals, which would reduce driving comfort.

[0118] In step S135, a trailer brake signal TBS is generated, also known as "First-in-Shot". This step provides a pressure peak to fill the line on the trailer. Since trailer sizes vary in agricultural and commercial settings, the line of the trailer braking system may also differ; therefore, this step is provided to maintain system bias and enhance responsiveness. The height of the trailer brake signal TBS, or the trailer brake actuation pressure, must be selected to be high enough to fill the line, but low enough to avoid excessive braking reaction force, which would cause bumps and negatively impact driving comfort. Therefore, "First-in-Shot" is time-controlled and depends on the driver deceleration requirement DD as determined in step S200.

[0119] If the deceleration is caused by the operator using the speed pedal 71 (obtain the status parameter SP) DL If =0), then the initial pressure P FIS It will be 300 kPa and the duration is set to 0.03 s.

[0120] If the deceleration is caused by the operator using drive lever 72 (obtain state parameter SP) DL If =1), then the pressure level and duration depend on the state parameter SP. AS The provided acceleration rate input setting is 73: For SP AS =1 (acceleration input 73 is set to Level I, representing the slowest deceleration), initial pressure P FIS It will be 300 kPA and the duration is set to 0.02 s.

[0121] For SP AS=2 (Acceleration input 73 is set to Level II), First strike pressure P FIS It will be 300 kPA (or alternatively, 320 kPA) and the duration is set to 0.03 s.

[0122] For SP AS =3 (Acceleration input 73 is set to Level III), First strike pressure P FIS It will be 300 kPA (or alternatively, 340 kPA) and the duration is set to 0.04 s.

[0123] For SP AS =4 (Acceleration input 73 is set to Level IV), First strike pressure P FIS It will be 300 kPA (or alternatively, 360 kPA) and the duration is set to 0.05 s.

[0124] If the deceleration is caused by cruise control (receiving "Yes" in step S240), then the state parameter SP is obtained in step S242. CC =1, or if the deceleration is caused by starting the reverse mode (receiving "Yes" in step S250) thus obtaining the state parameter SP in step S252. REV If the result is 1, then the same value will be used.

[0125] If the deceleration is caused by reducing the engine speed using step S260, then the result is "yes" (and the state parameter SP) ENG If set to 1), then the pilot pressure P P,0 Set to 80 kPA

[0126] In the embodiment, the initial pressure P FIS The setting value will be 300 kPA, and it depends on the state parameter SP. AS The duration is shared under different deceleration conditions (state parameter SP) DL SP CA SP CC SP REV SP ENG One of them is set to 1), but alternatively, the conditions for each deceleration can be defined differently.

[0127] In addition, the two correction factors f1 and f2 are multiplied by the pre-emptive pressure P. FIS To determine the trailer braking signal p TBS : P TBS = f1×f2 ×P FIS (E8) The correction factor f1 is in the range of >0..1, taking into account the fact that as vehicle speed increases, high initial pressure peaks often cause the trailer to bounce, negatively impacting driving comfort. On the other hand, when vehicle combination 1 is traveling downhill, the trailer braking system should respond as quickly as possible. The formula for the correction factor f1 is:

[0128] thus v Limit This refers to vehicle speed; below this speed, the initial pressure should be reduced. This value is set to 25 kph. α Limit This refers to the tilt angle; below this angle, the initial pressure should be at its maximum level, regardless of vehicle speed. This value is set to -5°. The correction factor f2 is also in the range of >0..1, taking into account the fact that the "initial" pressure level is reduced during this process to avoid overshoot in the trailer brake actuation pressure, which would reduce driving comfort. The formula for the correction factor f2 is: For the first braking interval (C=0):

[0129] For any subsequent braking interval (C>0):

[0130] thus P P,0 It is the pilot pressure determined in step S131 from a predetermined set of parameters.

[0131] P P,c It is the pilot pressure determined in step S132 from the previous braking interval. P Limit This is a pressure limit; below this limit, the initial attack gradually decreases. It could be 100 kPa. After the time-controlled trailer brake signal TBS is generated in step S135, step S140 generates the trailer brake signal TBS directly based on the pressure determination as described in steps 131 and 132. The trailer brake signal TBS generated in step S135 remains constant until the ECU is generating other pressure signals TBS, as illustrated herein.

[0132] The main advantage of applying pilot pressure based on the deceleration conditions indicated by the HMI input is that it initiates trailer brake actuation initially without first determining the physical values ​​of the deceleration or coupling force, making trailer brake activation more proactive and faster. Even when coupling force is taken into account in step S206a, the pilot pressure is not dependent on its magnitude in the initial step.

[0133] In step S145, the process waits for 0.75 seconds to allow the ECU to determine the actual connection force F as described in step S300. C, actual Consider the influence of the trailer braking signal TBS generated in steps S135 and S140, and the obtained actual coupling force F. C, actual The change in force requires a waiting period. Otherwise, the ongoing process will be based on the changing connecting force F under the influence of steps S135 and S140. C, actual .

[0134] In particular, step S140 is used to provide a rapid response to deceleration in the form of a trailer brake signal TBS based on a predetermined pressure value, while simultaneously applying a 3-point control algorithm to determine the trailer brake signal TBS during the process. This allows the system to respond first.

[0135] As in Figure 5 As detailed in the description, the control algorithm is executed in step S400.

[0136] Steps S400 and subsequent steps S401 to S490 primarily involve controlling the trailer brake signal TBS using a 3-point controller. Typically, the 3-point controller represents a discontinuous controller type and takes three values: 1, 0, and -1. Regarding the generation of the trailer brake signal TBS, the pressure value of the trailer brake signal TBS is increased, kept constant, or decreased, respectively. Compared to continuous controller types (such as P, I, or D controllers or combinations thereof), 3-point controllers tend to have less overshoot and are easier to handle in setting parameters to influence controller dynamics. In particular, these values ​​can be more easily adapted to operating conditions, which can be done by the driver or trained maintenance personnel.

[0137] After starting from step S401, step S405 sets the status parameter—the in-shot parameter SP. IS Similar to the initial firing described in step S135, the injection is a time-controlled pressure peak, but it is applied in conjunction with a 3-point controller. If the injection parameter SP... IS =0, then no advance is provided; if the advance parameter SP IS=1, then injection is provided. Injection is used to improve responsiveness by supporting pressure buildup in the trailer braking system 40. However, since pressure spikes can cause trailer swaying, injection can be deactivated if the coupling force (a constantly determined indicator) drops rapidly. Further injection can be omitted when a rapid drop (determined in step S300) indicates a rapid response to the trailer braking signal TBS. Injection is described in more detail herein.

[0138] In parallel with (or after) step S405, step S406 is performed, in which the ECU takes a predetermined value that is limited by the lower connecting force F. C, L and the connecting force F C, L The defined range of connection force is required to implement a 3-point controller and is described in this document.

[0139] Next, in step S407, the second interval counter i (also known as the controller interval counter) is set to zero.

[0140] In step S410, the number of control intervals is determined using the controller interval counter i. In the first interval where counter i = 0, the method proceeds to step S415, where the controller pressure p... PC,0 Set to the value p determined in step S140 P .

[0141] For the next interval (i>0) and using step S416, the controller pressure p PC,0 Taken from the subsequent controller interval stored in step S465 and using p PC,i Depicting. The advantage obtained in this way is that, under controller pressure p... PC,0 Subsequently, the value generated last in the previous controller interval is always received. This avoids trailer brake signal spikes between braking intervals, which would reduce driving comfort.

[0142] Using step S420, in steps S415 and S416, the 3-point controller is based on the controller pressure p. PC,0 Use the initial settings to adjust the pressure value.

[0143] Returning to step S406, now, the details of the lower connecting force F are explained. C,L and the connecting force F C,L Limited connection force band. Both values ​​have negative signs (because they are hindering the vehicle) and require operation of the 3-point controller.

[0144] Lower connecting force F C,LThis value should not be lower than a specified value, as it could cause vehicle 10 to become unstable due to the applied forces and the resulting yaw moment about the vertical vehicle axis. This value is stored in the ECU and can vary depending on the vehicle configuration. For example, a lightweight vehicle cannot withstand the same force / yaw moment as a heavier vehicle 10. The same applies to factors that depend on the track width or wheel width, which also affect vehicle stability.

[0145] Upper connecting force F C,L This indicates a value that should not be exceeded, because brake actuation should cease before the coupling force reaches zero. The driver requires that the trailer be able to coast, for example, when vehicle assembly 1 approaches a road intersection. This means that a small coupling force is acceptable.

[0146] Using steps S420, S435, and S437, the 3-point controller checks the actual connection force F. C, actual Relative to the connecting force F from below C,L and the connecting force F C,L The value of the limited connecting force band.

[0147] If the actual connecting force F C, actual Within the connecting force band, step S430 sets the controller pressure p. PC,i = p PC,0 This means that the pressure value determined in step S415 or S416 is taken without pressure adjustment.

[0148] If, as checked in step S435, the actual connection force F C, actual Lower than the lower connecting force F C,L Then branch B436 is executed, and step S438 sets the controller pressure to increase, where ΔP PC =ΔP PC,set ΔP PC,set The value is stored in the ECU and is 15 kPa. This means the pressure will increase to increase the braking force on the trailer.

[0149] If step 435 is not met, the actual connection force F C, actual Exceeding the upper connecting force F C,U Then branch B437 and step S439 set the controller pressure to increase, where ΔP PC =-ΔP PC,set This means that the pressure will be reduced to decrease the braking force on the trailer.

[0150] The method then proceeds in two parallel branches to steps encircled by dashed lines 440, which are used to apply the advance.

[0151] After branch B436, if the injection parameter SP is changed in step S405 ISIf set to 1 (indicating injection initiation), step S441 leads to step S445. Otherwise, the method proceeds to step 451 without applying injection. In step S445, injection parameters are set to limit the time-controlled pressure increase, where for a duration t... IS =t IS1 ΔP IS =ΔP IC Value ΔP IC,set and time t IS1 It is stored in the CU and is 100 kPa and 0.05 s.

[0152] After branch B437, if the injection parameter SP is changed in step S405 IS If set to 1 (indicating injection initiation), step S442 leads to step S446. Otherwise, the method proceeds to step 451 without applying injection. In step S446, injection parameters are set to limit the time-controlled increase in injection pressure, wherein for a duration t... IS =t IS2 ΔP IS = - ΔP IC,set (Decreased due to the negative sign). Value ΔP IC,set and time t IS2 It is stored in the CU and is 100 kPa and 0.1 s. Similar to step S445, the duration in this step is longer due to the fact that the trailer braking system has a longer reaction time when the pressure decreases. This is balanced by the longer injection duration.

[0153] Step S450 continues with steps S445 and S446, where the pressure value is set as follows: When the injection is initiated, the injection pressure P IS Calculated by the following formula p IS = p PC,0 +Δp PC +Δp IS (E9.1) This means that by controlling the pressure p PC,0 (As set in step S415 or step S416), controller pressure increases by ΔP PC (As set in step S438 or S439) and the injection pressure increases by ΔP IS The sum of (as set in step S445 or step S446) is used to receive the pressure for injection.

[0154] In addition, the controller pressure p PC,i Calculated by the following formula

[0155] PPC,i = p PC,0 +Δp PC (E9.2)

[0156] This means that by controlling the pressure p PC,0 (As set in step S415 or step S416), controller pressure increases by ΔP PC (As set in step S438 or step S439) the sum but without an increase in injection pressure ΔP IS In the case of receiving pressure for the controller.

[0157] In step S455, the ECU generates a trailer braking signal TBS, wherein during the duration t IS Interior trailer brake signal p TBS =p IS This step covers the trailer brake signal TBS generated in step S140 (in... Figure 2 middle).

[0158] If injection is not initiated in step S441 or S442, the controller pressure p is calculated in step S451 using the following formula. PC,i

[0159] P PC,i = p PC,0 +Δp PC (E9.3)

[0160] After one of steps S430, S451, or S455, the method proceeds to step S460, which generates the trailer braking signal p determined in step S430, S451, or S451. TBS =P PC,i The braking signal is not time-controlled and is therefore held until the next controller interval.

[0161] Then, in step S465, the final value of the trailer brake signal TBS is stored in the ECU for consideration in the next controller interval in step S416.

[0162] Alternatively, step S430 can cause the method to proceed to step S465 because there is no increase in pressure, and in step S140 (see...) Figure 2 The trailer braking pressure generated during the process is maintained.

[0163] In step S475, the controller interval counter i is incremented by 1 to indicate the subsequent interval requested in step S410.

[0164] In step S480, the timer value is controlled for t0. If the timer value t0 is less than 4s, the method proceeds to loop L481, which includes step S485, such that the process waits for t3 = 0.5s, allowing the ECU to determine the actual coupling force F as described in step S300. C, actual And return.

[0165] In step S145, the process waits for 0.75 seconds to allow the ECU to determine the actual connection force F as described in step S300. C, actual Then return to the point before step 410.

[0166] If the timer value t0 exceeds 4 seconds in step S480, then step S490 terminates sub-procedure S400 and returns to the previous state. Figure 2 The main method M100 is described in the text.

[0167] In summary, subprocess S400 continuously adjusts the trailer brake signal TBS by applying a 3-point controller and optional injection until a time of 4 seconds is reached. Simultaneously, the process passes through several controller intervals, whereby subsequent intervals are based on the trailer brake signal TBS generated in the previous intervals.

[0168] Now back Figure 2 In step S150, the last value of the trailer brake signal is stored in the ECU for consideration in the next braking interval in step S132.

[0169] Subsequently, in step S475, the braking interval counter c is incremented by 1 to characterize the subsequent interval requested in step S125.

[0170] As already mentioned, a timer value T0 is provided to ensure that brake actuation does not start for more than 5 seconds. To prevent the trailer brake signal TBS (and brake actuation) from suddenly dropping to zero, subprocess S400 aborts after 4 seconds. The remaining 1 second is used to reduce the trailer brake signal TBS to zero before 5 seconds have elapsed.

[0171] Based on the final trailer brake signal TBS and the ECU cycle time (which is the time required to execute a simple processor operation in the ECU), step S156 calculates the slope pressure drop Δp according to the following formula. R :

[0172] thus t C This is the processing cycle time in the ECU, which is 50 ms. t R The ramp time is 1 second. P TBV The final trailer braking signal (TBS) For the final trailer braking signal TBS at 100 kPa, E10 will determine the slope pressure drop Δp at 4 kPa. R .

[0173] Therefore, as long as step S160 does not indicate that the trailer brake signal TBS is zero, loop L161 and step S162 are repeated to generate Δp R Decrease the trailer brake signal TBS. Loop L161 repeats and returns to before step S160 until the trailer brake signal TBS is zero.

[0174] As long as a start signal exists in step S165 (where SP is present) CA If t2 = 1), then the process continues loop L166, where step S170 includes a waiting period of t2 = 1s, and returns to step S121 to continue the next braking interval.

[0175] If step S165 determines that no start signal exists, then step S175 checks whether the shutdown condition is met, causing the method to end at step S180. We have already selected ignition off (OFF) in step S175.

[0176] Figure 7 The results of the method according to the present invention are briefly described.

[0177] The horizontal axis depicts the time it takes for this method to be performed.

[0178] The vertical axis represents two parts: The upper part is under pressure p TBS Depicting trailer brake signals TBS The lower part is depicted as the measured connection force F determined in step S300. C, actual , including by F C,U and F C,L The limited connecting force band, therefore, F C,U =-2000 N and F C,L= -4000 N. The measured connection force F C, actual The curve B is smoothed out, as if the curve would exhibit a continuous oscillation cycle time of 50 ms.

[0179] As best seen in graph A, in step S121, the timer value of t0 is set to zero. Since this is the first braking interval when C=0, step S131 determines the initial pressure value P generated in step S135. FISDuring the waiting period in step S145, the pilot pressure P is maintained. P Then, the process proceeds to step S400.

[0180] Based on the actual pressure, and based on the determinations made in steps S438, S445, and S450, step S455 applies a pressure with p. IS The injection. Then, in step S460, the controller pressure P is generated based on the determination in step S438. PC Steps S438, S445, and S450 involve the connecting force F. C, actual Below F C,L The positive pressure transmitted increases over time. This process is repeated until the connecting force F increases. C, actual Higher than F C,L Until then. Then, in steps S439, S446, and S450, an increase in negative pressure is determined to generate the injection p in step S455. IS And in step 460, the controller pressure P is generated. PC .

[0181] This is provided until timer t0 reaches 4s in step S480 and the 3-point controller stops. Next, in steps L161 / s162, the trailer brake signal TBS and pressure p... TBS The pressure decreases. After a 5-second (overall, or 1-second descent ramp) period, the pressure p... TBS The value will be zero. Then, a 1-second wait period is applied using step S170.

[0182] If the start signal remains valid, the process restarts at the next braking interval (c=1), but then proceeds through step S132 from the previous interval P. PC,1 The pressure value begins, and pre-launch, advance, and pressure control are applied as previously described.

[0183] At the time indicated by the dashed line X, the connecting force F C, actual Within the connecting force band, the trailer brake signal TBS and pressure p are... TBS Keep it unchanged until you reach 4 seconds again and start going downhill.

[0184] Other embodiments of the invention relate to the generation of a warning message provided to the driver, which may include other embodiments of the invention, providing the embodiment to detect whether a trailer is attached, and further, for trailers equipped with a braking system, determining the temperature of the trailer braking system.

[0185] refer to Figure 2 The process branch, for example, performs subprocess S500 in parallel with subprocess S300.

[0186] refer to Figure 8The system provides a subprocess S500 to generate a warning message on the HMI terminal 75. Alternatively, this information may be indicated to the driver via an audio device or any other suitable device.

[0187] Subprocess S500 begins at step S501 and proceeds to step 505 to check whether the electronic trailer braking function is activated (ETCV=1). Preferably, the electronic trailer braking function is always activated during operation, for example, when ignition is started and / or the electronic vehicle control unit (ECU) is powered on.

[0188] In step S508, the parameter SP is initially processed. DT1 Set to 0 as the default condition. Parameter SP DT1 This is a status parameter indicating that trailer detection is performed correctly in subprocess S600 as described below. Because this is not yet provided at this stage, parameter SP is not available before subprocess S600 begins. DT1 It is set to 0. As explained below, parameter SP... DT1 The provision of this also allows the method to be processed without trailer inspection.

[0189] The next step begins subprocess S600 to provide trailer detection, and then begins the next subprocess S700 to determine the trailer brake temperature. As indicated above, subprocess S600 is an optional step.

[0190] Now, for reference Figure 9 The sub-process S600 is described in detail. Similar to step S508, step S615 will change the parameter SP. DT1 Set to 0 to provide a default condition. Then, the process branches to step S605, where the activation of the electronic trailer brake function is checked. If it is not activated (ETCV=0), the process returns to before step S615. If the electronic trailer brake function is activated (ETCV=1), steps S610 to S614 are used to check other parameters described below, thereby changing the order: In step S610, the process checks whether the vehicle is traveling on a slope. If the current inclination α is greater than the inclination angle α0, the process checks whether the vehicle is traveling on a slope. TD,min (It can be about 3°), then process the following parameter. If the current tilt α is less than it, then process returns to before step S615.

[0191] In step S611, the trailer brake pressure p stored in step S150 is checked. TBS ( Figure 2 (as shown in the image) Whether it is greater than p TBSTD,min(This could be approximately 80 kPa). If so, then process one of the following parameters if the current trailer braking pressure p TBS Below p TBSTD,min If the signal is not above p, the process returns to step S615. This step checks whether the last stored and applied trailer brake signal is higher than the level that causes the trailer brakes to supply braking force. Tests have shown that below p TBSTD,min At that time, the signal did not cause effective braking of the trailer, but only caused the brake line to be filled or the brake actuator to move to make slight contact with the brake disc.

[0192] In step S612, the process checks whether the tractor's service brake is not engaged (SP). SB =0). If yes, then process the next parameter; otherwise (SP). SB If the value is 1, the process returns to step S615. Any activation of the service brake will override the electronic trailer brake provided above.

[0193] In step S613, the process checks whether the tractor's parking brake is not engaged (SP). PB =0). If yes, then process the next parameter; otherwise (SP). PB If =1), the process returns to step S615. Any activation of the parking brake will override the electronic trailer brake provided above.

[0194] In step S614, the process checks whether the current tilt α remains at a low value α. TD,L1 (For example, 3°) and higher values ​​of α TD,L2 Within a slope range of, for example, 20°. If yes, the process proceeds to step S620; otherwise, the process returns to step S615. In other words, the vehicle must remain on the slope during trailer inspection.

[0195] It is conceivable that the parameter α used for these comparisons TD,min p TBSTD,min α TD,L1 α TD,L2 There is also the state parameter SP. SB and SP PB It can be stored in the ECU, and can vary depending on the vehicle configuration. Optionally, some of the conditions can be used.

[0196] If the condition is not met, the process returns to step S615, so that parameter SP... DT1 Keep it at 0 for use in other processes (especially S500). This means the trailer detection failed.

[0197] If all conditions are met, then in step S620, set parameter SP. DT2 =0 to provide a default condition. Parameter SP DT2 It indicates that a trailer (SP) has been detected. DT2 =1) or the tractor is operated without a trailer (SP) DT2 The state parameter (=0) will be explained in detail below.

[0198] In step S625, the processing includes a timer loop that waits until the first timer value t0 is also set to zero (seconds) in step S121 to start a timer for the braking interval. Briefly, step S625 enables subsequent processing to be performed in parallel with steps following step S121 in the main processing M100, to limit... Figure 2 The braking interval described in [the text]. Alternatively, as [the text]... Figure 2 The braking interval counter c described in the document can be used to determine the duration of the braking interval.

[0199] In step S630, the processing is based on, for example, using Figure 3 The connecting force F described in step S300 C, actula The predetermined number of iterations n is determined by continuous determination. TD Average connecting force F within DT This parameter is used to detect the presence of a trailer, as described below.

[0200] In step S635, the processing includes other timer loops that wait until the first timer value t0 reaches 4 seconds. For example, in main process M100 ( Figure 2 As described in S400, if the timer value is 4 seconds, then in steps S160 and S162, the trailer brake pressure signal F... TBS Slope.

[0201] Step S640 saves the first average connection force value F determined in step S630. TD1 The following describes other details.

[0202] In step S645, the process continues to wait until the trailer brake pressure signal F is received. TBS Descend diagonally to F using steps S160 / S162. TBS =0.

[0203] Trailer brake pressure signal F TBS When the value is 0, step S650 saves the second average connection force value F determined in step S630. TD2 The following describes other details.

[0204] In step S655, the waiting time offset Δt is processed. td =0.5 seconds. At this time, the trailer brake pressure signal F TBS The next braking interval (indicated by c) increases again.

[0205] Step S660 saves the third average connection force value F determined in step S630. TD3 .

[0206] The first average connecting force value F in steps S640, S650 and S660 TD1 Second average connecting force value F TD2 and the third average connection force value F TD2 The value now enables the electronic vehicle control unit (ECU) to determine the trailer detection parameters in steps S665 and S670 according to other aspects of the invention, now referring to Figure 12 This will be explained in more detail.

[0207] Figure 12 The horizontal axis briefly describes the time taken for the method to proceed.

[0208] The vertical axis represents two parts: The upper part is under pressure p TBS Depicting trailer brake signals TBS The lower part depicts the average connecting force F determined in step S630. TD Average connecting force F TD Curve B

[0209] In step S665, the inspection difference F is processed. TD2 -F TD1 Greater than the first difference ΔF stored in the ECU to reduce trailer braking pressure TDL . refer to Figure 12 This is done to check when considering the force exerted by the trailer on the tractor as negative, in (using Figure 2 The description addresses whether the pressure drop during steps S160 / 162 results in a significant change in the coupling force. If no trailer with a trailer braking system is attached, the release of the trailer brake does not affect the coupling force. If a trailer with a trailer braking system is attached (and the conditions described in steps S610 to S614 are met), the coupling force increases in the negative direction when the trailer pushes the tractor without the trailer brake. In the illustrated embodiment, F... TD1 Approximately -3000N and F TD2 Approximately -3500 N. This is in reference to ΔF. tdl =-300 N, the predetermined value, the difference F TD2-F TD1 This will result in -500 N, which is greater than the first difference ΔF in the negative direction. TDL If the conditions of step S665 are met, the process moves to the next step S670. If not, the process moves to the step before step S680, which will be described below.

[0210] In step S670, the inspection difference F is processed. TD3 -F TD2 Greater than the second difference ΔF stored in the ECU to increase trailer braking pressure TDR . refer to Figure 12 This is done to check that when considering the force exerted by the trailer on the tractor is negative, from (using Figure 5 , Figure 11A , Figure 11B The description of whether increasing the trailer brake pressure in the next braking interval starting from step S460 results in a significant change in the coupling force. If no trailer with a trailer brake system is attached, the increase in trailer brake pressure will not affect the coupling force. If a trailer with a trailer brake system is attached (and the conditions described in steps S610 to S614 are met), the coupling force will decrease in the negative direction due to the reduced pushing effect caused by the tension of the trailer-tractor combination. In the illustrated embodiment, F TD3 Approximately -3200 N and F TD2 Approximately -3500 N. This is in reference to ΔF. tdl =200 N, the predetermined value, the difference F TD3 - F TD2 This will result in 300 N, which is greater than the second difference ΔF. TDR If the conditions of step S665 are met, the process moves to the next step S670. If not, the process moves to the step before step S680, which will be described below.

[0211] If the conditions defined in steps S670 and S675 are met, the process proceeds to step S675, where parameter SP... DT2 When set to 1, it indicates that a trailer has been detected.

[0212] If the conditions defined in steps S670 and S675 are not met, then steps S670 and S675 proceed to step S680, where parameter SP... DT2 When set to 0, it instructs the tractor to operate without a trailer.

[0213] With parameter SP DT2 In comparison, parameter SP DT1 Only considering parameter SP DT2 Setting it to 0 or 1 indicates whether the trailer connection is disabled. If not, parameter SP...DT1 Keep it at 0.

[0214] Using loop L685, before returning to step S635, restart the connection force determination to continuously determine the state parameter SP. DT1 and SP DT2 And forward the results to other subroutines, especially Figure 8 Subroutine S500. Alternatively, subroutine S600 may terminate at step S690, such that the state parameter SP... DT1 and SP DT1 This is determined only during the two braking intervals. Then, subprocess S600 can be restarted in subprocess S500 using step S508.

[0215] Back Figure 8 Sub-process S500 then proceeds to another sub-process S700 provided for determining the trailer brake temperature.

[0216] refer to Figure 10 Subroutine S700 begins with step S701. In step S705, the temperature correction factor K is... TP Set it to 0 as the default condition. Further details are explained below.

[0217] In step S710, the time value t TP It is set to 0. Further details are explained below.

[0218] Steps S715 and S716 are provided to check certain operating conditions: Step S715 ensures the vehicle is on relatively flat terrain at α TPmax >α>α TPmin Under these conditions, α TPmin =1° and α TPmax =5° is stored as a setting in the ECU.

[0219] Step S716 ensures vehicle speed V V Keep it constant.

[0220] If these conditions are met within the duration (e.g., 2 seconds) defined by step S720 and time loop L721, the process proceeds to step S752 as described below.

[0221] If these conditions are met within the duration defined by step S720 and time loop L721, the process proceeds to step S730, based on the connecting force F. C, actual The predetermined number of cycles n is determined by continuous determination. TP Average connecting force F within TP, such as using Figure 3 The steps described in step S300 are as follows. Because the conditions defined in steps S715 and S716 imply that the vehicle assembly operates with the tractor pulling the trailer (trailer brakes not engaged), the average coupling force value F... TP It was determined to be positive, which is for using the average connecting force value F TP The following steps, S740 and S74, which provide rough information about the trailer weight, are important. Since trailer weight is a significant factor affecting trailer brake temperature during brake activation, the average coupling force value F is used. TP To estimate the trailer weight, and accordingly set the temperature correction factor K as described below. TP : If in step S740, the average connecting force value F TP Below the first limit value F Tp,limit1 (For example, 500N), which would indicate a trailer with a light weight attached, causing the temperature correction factor K to be adjusted in step S750. TP Set it to 0.6.

[0222] If the conditions in step S740 are not met, the process continues to step S741.

[0223] If in step S741, the average connecting force value F TP First limit value F Tp, limit1 Second limit value F TP, limit2 For example, between 500 N and 1500 N, this would indicate that a medium-weight trailer is attached, causing the temperature correction factor K to be applied in step S751. TP Set it to 0.8.

[0224] If steps S740 or S741 are not met, the average connection force value F TP It must exceed the second limit value F TP, limit2 (For example, 1500N), this will indicate a trailer with a heavy attached weight, causing the temperature correction factor K to be adjusted in step S752. TP Set to 1. If the conditions defined in steps S715 and S716 are not met within the duration defined by step S720 and time loop L721, then the temperature correction factor K is also set in step S752. Tp Set to 1.

[0225] In summary, based on the average connecting force value F TP The steps starting with S730 provide an estimate of the vehicle's weight, or more precisely, based on the average coupling force value F. TP Assign three trailer weights: light, medium, and heavy, to set a temperature correction factor K.TP .

[0226] Use the temperature correction factor K TP To adjust the trailer brake temperature TP TBS,DEF .

[0227] First, step S760 uses a temperature model to determine the trailer brake temperature TP. TBS,DEF Temperature models can use parameters such as trailer brake pressure T. TBS Trailer braking duration t TBS Parameters such as (how long the trailer brake pressure is maintained) and ambient temperature (TP) are also important. Ambient Other parameters. Trailer braking pressure T TBS and trailer braking duration t TBS This can be determined, for example, during M100 or subroutine S400. The ambient temperature may already be available in the ECU, for example, for HVAC control.

[0228] Therefore, considering the brake (or clutch) at a higher trailer braking pressure T TBS and longer trailer braking duration t TBS More heat is often generated underneath. This is also true when the vehicle or trailer is operating in hot environments. The main drawback of this model is that it does not include the weight of the trailer.

[0229] The temperature model is not detailed because it is known in many braking applications, but also in clutches in vehicle or stationary applications.

[0230] In step S770, the process is performed by passing TP TBS,DEF With temperature correction factor K TP Multiply to calculate trailer brake temperature TP TBS .

[0231] The subroutine can end at step S790.

[0232] In summary, the S700 process estimates trailer weight based on the (average) coupling force during the pulling operation and corrects for brake temperature (determined by a known temperature model), so that the subroutine provides a lower trailer brake temperature TP for lightweight trailers. TBS (Because the thermal shock is lower when the weight is smaller), providing a higher trailer brake temperature (TP) for medium or heavy-duty trailers. TBS (Because thermal shock increases with trailer weight). Further use of the trailer brake temperature TP TBS A temperature warning is generated for the driver, so the main advantage of this treatment is that the trailer brake temperature takes the trailer weight into account.

[0233] Back Figure 8Subroutine S500, having determined the parameters for trailer detection and trailer brake temperature, proceeds to generate a warning message as described below: In step S510, the process checks whether the trailer detection failed. If so, the process begins at step S525. If the trailer detection was processed correctly, step S515 checks whether a trailer is attached or whether the tractor is operating without a trailer (SP). TD2 =1).

[0234] If the condition SP is met TD2 If the value is 1, then the process begins at step S525 to set the warning level parameter WL to 0, which is the default value. Therefore, the default value indicates that the trailer brake is under conditions at which no impact on the methods described herein is required.

[0235] In step S530, the trailer brake temperature TP determined in subroutine S700 is checked. TBS Does it exceed the first temperature limit TP? TBS,L1 If not, the process returns to the state prior to step S525. In other words, the process waits until the first temperature limit is exceeded. TBS,L1 Then further processing will be carried out.

[0236] If this condition is met, step S535 sets the warning level parameter WL to 1, indicating that the first warning level has been reached. As a result, step S536 generates a first temperature message (temperature level 1) as depicted on the HMI terminal 75 in Figure 13A. This message includes a graphical representation of the trailer brake temperature TP. TBS The temperature bar displays 800. The temperature bar display 800 contains three color zones: The trailer brake temperature (TP) is represented by green. TBS Below TP TBS,L1 Part 800a (WL=0).

[0237] Next, orange is used to depict the trailer brake temperature TP. TBS In TP TBS,L1 and TP TBS,L2 The portion of 800b within the range (WL=1).

[0238] The trailer brake temperature TP is indicated by red. TBS Exceeding TP TBS,L2 Part 800c (WL=2). In step S536, part 800c turns gray.

[0239] In addition, a warning message 801 is generated to alert the driver that the trailer brake temperature is high and to suggest reducing the vehicle speed. In conjunction with the first temperature message, step S537 indicates the status of the electronic trailer brake, including a symbol 810a indicating that the electronic trailer brake hold is active.

[0240] If a trailer detection failure is detected as shown in step S537 (SP) TD1 If the value is 0, then as depicted in Figure 13B, an additional message 820 will be generated in step S539 to inform the driver that the trailer detection has failed. The warning message 801 depicted in Figure 13a can appear alternately.

[0241] Parallel step S540 sets the pressure limit value p TBS,max Set to a predetermined value stored in the ECU. Use this pressure value to limit the trailer brake pressure signal p. TBS If used later Figure 11A , Figure 11B Described.

[0242] In the next step S550, the trailer brake temperature TP is checked. TBS Should it remain in TP? TBS,L0 and TP TBS,L1 The range between [the specified range]. This means that the warning level parameter WL=1 remains unchanged. If so, the process returns to step S535 via loop L551.

[0243] Before proceeding further, the previously described process was performed on parameter SP upon detecting a trailer. TD2 =1 describes. If SP in step S515 TD2 =0, then the tractor operates without a trailer and begins from branch B516 leading to step S520. Step S520 is provided to check (similar to step S530) the trailer brake temperature TP. TBS Has the first temperature limit been exceeded? TBS,L1 If not, the process loops back to the step before S525. If the condition is met, the process follows branch B521 leading to step 560. In other words, the process skips temperature warning level 1, which starts with warning level parameter WL=1, and instead begins the next temperature warning level 2. The main advantage of this is that when the trailer detection status indicates that the tractor is operating without a trailer, a warning level is only generated when the temperature exceeds a high level, allowing the driver to check whether a trailer is attached even if no trailer is detected. This improves safety while avoiding numerous warnings.

[0244] Alternatively, after step S520, the process may follow alternative branch B522 to disable electronic trailer braking, as described in step S570.

[0245] In step S560, the trailer brake temperature TP is checked. TBS Does it exceed TP? TBS,L2 If not, the process returns to step S525 via loop L561. If yes, the next temperature level is reached in step S565 and the warning level parameter WL is set to 2.

[0246] As a result, step S566 generates a second temperature message (temperature level 2) as depicted in Figure 13c, shown on the HMI terminal 75. This message includes a graphical representation of the trailer brake temperature TP. TBS The temperature bar displays 800. The temperature bar display 800 contains three color zones: The trailer brake temperature (TP) is represented by green. TBS Below TP TBS,L1 Part 800a (WL=0).

[0247] The trailer brake temperature (TP) is depicted in orange. TBS In TP TBS,L1 and TP TBS,L2 The portion of 800b within the range (WL=1).

[0248] The trailer brake temperature TP is indicated by red. TBS Exceeding TP TBS,L2 (WL=2) part 800c.

[0249] If a trailer detection failure is detected as shown in step S567 (SP) TD1 =0), then as Figure 13D As described in step S568, an additional message 820 will be generated to inform the driver that the trailer detection has failed.

[0250] In step S570, the electronic trailer brake is disabled by setting ETCV=0, which causes a message indicating that the electronic trailer brake is disabled, as shown by symbol 810b, to be generated in step S571.

[0251] As the process continues along branch L575, step S580 checks the trailer brake temperature TP. TBS Has it fallen below TP? TBS,L0 TP TBS,L0This indicates the temperature level at which the brake has sufficiently cooled down after exceeding a previous temperature value. If not, the process returns via a loop until the condition is met. If yes, the process proceeds to step S585, where the electronic trailer brake is (re-activated), and symbol 810A (similar to Figure 13A) is shown again. The process then returns to step S600.

[0252] Regarding the temperature limits, these values ​​are depicted in Figure 13A, hence TP TBS, L0 < TP TBS, L1 < TP TBS, L2 .

[0253] The disappearance of the aforementioned message can be confirmed by the driver. Alternatively, the message may disappear after a certain period of time. More alternatively, the message may be displayed at a large scale on the HMI 75 and then reduced to a smaller size after a certain period of time. Instead of an optical message, the message may be provided by voice or any other suitable means that attracts the driver's attention.

[0254] In summary, subroutine S500 is designed to provide a two-level temperature warning when trailer detection has functioned correctly and an attached trailer with trailer braking system is detected. Additionally, in the event of trailer detection failure, the two-level temperature warning is maintained, but the driver is also prompted to check if a trailer is attached. This draws the driver's attention, requiring them to periodically check trailer brake temperature or monitor for brake fade, as the described procedure cannot reliably provide this crucial information.

[0255] When the trailer detection has been successfully processed and the trailer detection instructs the tractor to operate without a trailer, the processing skips the first warning level. Even if there may be no trailer, the driver is still informed, but only if the trailer brake temperature is high, to ensure that if the detection is erroneous in any other way, the driver is informed at this high brake temperature level. For example, if a trailer with a trailer braking system is attached, but the trailer braking system is not properly connected to the trailer, causing the trailer brake signal p... TBS If the brakes are not properly initiated by forwarding to the trailer, point out the problem to the driver and check the connection.

[0256] As indicated in the preceding description, the temperature monitoring and warning process also affects the trailer brake signal p. TBS Now, for reference Figure 2 , Figure 8 , Figure 11A , Figure 11B and Figure 12 Describe it.

[0257] Figure 11A and Figure 11B Similar to Figure 5 However, for clarity, it was divided into two parts. In use with Figure 5 Where the same components and references are used, they will not be described again. Figure 11A and Figure 11B The flowchart depicted in the image uses triangular transition markers a, b, c, d, and e to emphasize... Figure 11A and Figure 11B How is the connection processed?

[0258] like Figure 8 As described, step S535 sets the warning level parameter WL=1, and step S540 sets the pressure limit value p at the first temperature level 1. TBS,max Furthermore, when the second temperature level 2 is reached, step S565 sets the warning level parameter WL=2. Figure 11A and Figure 11B The subroutine S400 described uses parameters WL and p TBS,max To control the trailer braking signal p TBS As described below: In step S805, subroutine S400 checks if the temperature level is at level 2. If so, the process jumps to the end at step S490. (See reference) Figure 2 This will cause steps S160 and S162 to cause the pressure to slope down to p. TBS =0. In other words, when very high temperatures are reached, the trailer brakes are put into a non-operating state to allow them to cool down. Figure 14A This is illustrated schematically, where the time taken for the method to proceed is plotted on the horizontal axis, and the vertical axis is plotted against the pressure p. TBS The dashed line G1 represents the trailer brake signal TBS. The dashed line G1 indicates the trailer brake signal p when the warning level parameter WL=0 (therefore, the critical temperature for indicating temperature level 1 or 2 has not been reached). TBS The solid line graph G2 represents the trailer brake signal TBS when temperature level 2 (WL=2) is reached.

[0259] If temperature level 2 (WL=2) is not reached, the process begins from step S420 to initiate trailer brake signal generation based on the coupling force, as previously described in... Figure 5 As described in [the text]. If the condition in step S420 is met, then branch B811 with step S430 remains as [the text is incomplete]. Figure 5 As described in [the document], it will not be described further. If not, branch B812 proceeds to step S435.

[0260] If step S435 is not satisfied, it means that the actual connection force F C, actual Exceeding the upper connecting force F C,UThen branch B437 and step S439 are as follows Figure 5 The process is performed as described in steps S439, S442, and S446, and will not be described further. In other words, as described in steps S439, S442, and S446, the controller pressure p... PC,i It can still be reduced.

[0261] If, as checked in step S435, the actual connection force F C, actual Lower than the lower connecting force F C,L Then branch B436 will be executed. For example, in Figure 5 In the process described, this may initially lead to controller pressure p pc,i The increase is made, but step S820 first checks whether temperature level 1 (WL=1) has been reached. If not, the process proceeds to branch B821 and step S438, as follows. Figure 5 The description of increasing the trailer brake pressure signal p TBS Therefore, no further description is needed.

[0262] If step S820 determines that temperature level 1 (WL=1) has been reached, the method proceeds to step S830 via branch B822 to increase the pressure by Δp. TP Setting it to 0. This results in p in step S835. C,I It did not increase further.

[0263] refer to Figure 11B The process then proceeds to step S840 via transition marker c, where the method checks whether temperature level 1 (WL=1) has been reached. If temperature level 1 (WL=1) has not been reached, then in step S460, branch B841 is processed to generate trailer braking signal p. TBS = p C,i If temperature level 1 (WL=1) is reached, then in step S850, the trailer brake pressure signal p is checked. C,I Is it below the pressure limit p? TP,max If not, then in step S860, the trailer brake pressure signal p C,I Set to p TP,max Then return to branch B841 and step 460 to generate the trailer braking signal p. TBS = p C,I = p TP, max If so, processing returns to branch B841 to generate the trailer brake signal p in step S460. TBS =p C,i However, the braking pressure is not limited. Steps S840, S850, and S860 are used to enable the processing to maintain the trailer brake pressure signal p (determined in the previous controller interval i). C,IConstant, but if the trailer brake pressure signal p C,I Once it drops to the pressure limit p TP, max The following applies as long as the electronic trailer brake is activated and SP... CA =1 means it will not exceed the limit.

[0264] The processing results can be found Figure 14B Ideally, the time taken for the method to proceed is represented on the horizontal axis and the vertical axis is represented by the pressure p. TBS The trailer brake signal TBS is shown. The dashed line G3 represents the trailer brake signal P when the warning level parameter WL=0. TBS Therefore, the critical temperature indicating temperature level 1 or 2 was not reached. The solid line graph G4 represents the trailer brake signal TBS when temperature level 1 (WL=1) is reached. Graph G4 shows the trailer brake signal p. C,i It can be maintained above the pressure limit p TP, max Alternatively, a constant level can be reduced via step S446 (using steps S430 or S835), but if the pressure drops to the pressure limit p... TP, max The following steps, 850 / 860, ensure that the controller pressure p PC,i The pressure cannot be increased to the pressure limit p. TP, max Above a certain value, even if the coupling force may need to be changed according to step S435. Figure G5 depicts that the limit remains unchanged even at the start of the next interval C, as long as the start is not interrupted. When temperature level 1 is reached, this prevents increased thermal shock by generating increased trailer braking pressure.

[0265] Other steps S465 to S490 remain as follows Figure 5 As described in the text, it will not be described further.

[0266] In summary, the method according to the present invention ensures When temperature level 2 is reached, the controller pressure p PC,i Then the trailer braking signal p TBS Immediately descend. Because the trailer brake signal is not abruptly cut off, the driver can more easily experience the changing situation with the aid of a displayed warning.

[0267] When temperature level 1 is present, this method enables the trailer braking signal p to be applied based on the coupling force. TBS Maintain the same level or reduce the trailer braking signal p TBS Similarly, this avoids abruptly cutting off the trailer brake signal, making it easier for the driver to experience situations assisted by the displayed warning.

[0268] When temperature level 1 is present, this method also ensures that once the trailer braking signal p is received... TBS Below the pressure limit p TP, max The connection force will not cause the trailer braking signal p TBS Exceeding the pressure limit p TP, max This helps cool the trailer brakes to a more acceptable level.

[0269] When temperature level 1 or level 2 conditions are not present, the trailer brake signal p TBS It can be increased or decreased depending on the connection force.

Claims

1. A control system for controlling the operation of a trailer braking system associated with an agricultural vehicle-trailer combination, the control system comprising a vehicle control unit and configured to: Determine the trailer brake temperature; The determined trailer brake temperature is compared with one or more temperature thresholds to determine the temperature level conditions for the trailer brake. Based on the determined temperature level conditions, a trailer braking signal is generated for controlling the trailer braking system. The trailer brake signal is forwarded to the trailer brake control system to control its operation; The determined trailer brake temperature is compared with a first temperature threshold, and a basic temperature level condition (WL=0) is determined based on the fact that the determined trailer brake temperature is less than the first temperature threshold. as well as The determined trailer brake temperature is compared with a second temperature threshold, and a second temperature level condition (WL=2) is determined based on the determined trailer brake temperature exceeding the second temperature threshold.

2. The control system of claim 1 is configured to compare the determined trailer brake temperature with a first temperature threshold and a second temperature threshold, and to determine a first temperature level condition (WL=1) based on the determined trailer brake temperature being between the first temperature threshold and the second temperature threshold.

3. The control system according to claim 2, wherein, Based on the determination that the trailer brake temperature corresponds to the first temperature level condition (WL=1), the control system is configured to prohibit the increase of the trailer brake signal to prevent an increase in the pressure level associated with the trailer braking system.

4. The control system according to claim 2 or claim 3, wherein, Based on the determination that the trailer brake temperature corresponds to the first temperature level condition (WL=1), the control system is configured to limit the trailer brake signal to a first trailer brake signal limit value corresponding to the pressure limit of the trailer brake system.

5. The control system according to claim 4, wherein, Based on the determination that the trailer brake temperature corresponds to the first temperature level condition (WL=1), the control system is configured to prohibit the increase of the trailer brake signal when the trailer brake signal exceeds the first trailer brake signal limit value.

6. The control system according to claim 5, wherein, Under the first temperature level condition (WL=1), the control system is configured to limit the trailer braking signal to the first trailer braking signal limit when the trailer braking signal is lower than the first trailer braking signal limit.

7. The control system according to claim 1, wherein, Based on the determination that the trailer brake temperature corresponds to the second temperature level condition (WL=2), the control system is configured to sag the trailer brake signal to reduce the pressure level associated with the trailer braking system.

8. The control system according to claim 1 or 2, configured to determine the coupling force associated with the connection between the vehicle and the trailer.

9. The control system of claim 8, configured to determine the coupling force based on measurements of operating parameters of the transmission of the vehicle-trailer combination.

10. The control system of claim 8, configured to generate a trailer braking signal based on a determined coupling force associated with the connection between the vehicle and the trailer.

11. The control system according to claim 1 or 2, configured to generate and output a control signal for providing a warning message to the operator of the vehicle-trailer combination.

12. The control system according to claim 11, wherein, The warning message indicates the determined temperature of the trailer brake.

13. The control system according to claim 11, wherein, The warning message indicates that a trailer inspection has been confirmed.

14. The control system according to claim 11, wherein, The warning message indicates advice regarding reducing vehicle speed.

15. A braking system comprising, and / or controllable by, any one of claims 1 to 14.

16. An agricultural vehicle capable of being coupled to a trailer to form a vehicle-trailer combination, and comprising and / or controllable by the control system according to any one of claims 1 to 14.

17. A method for controlling the operation of a trailer braking system associated with an agricultural vehicle-trailer combination, comprising: Determine the trailer brake temperature; The determined trailer brake temperature is compared with one or more temperature thresholds to determine the temperature level conditions for the trailer brake. The trailer braking system is controlled according to the determined temperature level conditions; The determined trailer brake temperature is compared with a first temperature threshold, and a basic temperature level condition (WL=0) is determined based on the fact that the determined trailer brake temperature is less than the first temperature threshold. as well as The determined trailer brake temperature is compared with a second temperature threshold, and a second temperature level condition (WL=2) is determined based on the determined trailer brake temperature exceeding the second temperature threshold.

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