A method and apparatus for synchronizing brakes on a trailer added after the fact

Abstract

This invention provides a method and apparatus for synchronized braking of a retrofitted trailer. The method includes: acquiring the speed v1 of the tractor vehicle, the speed v2 of the trailer, and the brake pedal travel s; calculating the acceleration a1 of the tractor vehicle and the acceleration a2 of the trailer based on the speed v1 and v2 of the tractor vehicle using a state observer; determining whether the brake pedal travel s meets a first preset condition and / or whether the acceleration a1 of the tractor vehicle meets a second preset condition; if so, determining the braking torque applied to the trailer based on the deviation between the acceleration a1 of the tractor vehicle and the acceleration a2 of the trailer, and braking the trailer according to the braking torque. This invention does not rely on accelerometers or manual gain settings, and the output braking torque is linearly adjustable, achieving matching of braking forces between the tractor vehicle and the trailer vehicle, thereby improving driving safety and comfort.

Description

Technical Field

[0001] This invention relates to the field of vehicle equipment, and more particularly to a method and apparatus for synchronous braking of a retrofitted trailer. Background Technology

[0002] Currently, aftermarket trailer braking often employs inertial braking or on / off electromagnetic braking. This braking force has two states: release and braking. The braking force applied to the trailer cannot be perfectly matched to that of the towing vehicle, resulting in reduced driving comfort and, more seriously, impacting driving safety. Traditional solutions rely on accelerometers and manual gain settings. The accelerometer measures the deceleration *a* of the towing vehicle under braking, calculates the braking torque *T* applied to the trailer based on this deceleration *a*, and then outputs this braking torque *T* through a linear solenoid valve. This method has specific requirements for the accelerometer's installation position and angle, and the accelerometer measurement results introduce vehicle vibrations. Therefore, under certain operating conditions, the accelerometer cannot accurately reflect the braking state of the towing vehicle. Manually setting the gain requires obtaining the trailer's mass, which increases the difficulty for users. Summary of the Invention

[0003] This invention provides a method and apparatus for synchronous braking of a rear-mounted trailer. Using this method and apparatus, errors caused by vehicle body vibration introduced by the accelerometer can be effectively resolved, improving control accuracy, and eliminating the need for manual gain setting, thus enhancing ease of use.

[0004] In a first aspect, the present invention provides a method for synchronous braking of a retrofitted trailer, comprising: step 1, acquiring the speed v1 of the tractor, the speed v2 of the trailer, and the brake pedal travel s; step 2, establishing a state observer corresponding to the tractor and the trailer based on the speed v1 of the tractor and the speed v2 of the trailer, and calculating the acceleration a1 of the tractor and the acceleration a2 of the trailer based on the state observer corresponding to the tractor and the trailer; step 3, determining whether the brake pedal travel s satisfies a first preset condition and / or whether the acceleration a1 of the tractor satisfies a second preset condition, and if so, determining the braking torque applied to the trailer based on the deviation value of the acceleration a1 of the tractor and the acceleration a2 of the trailer, and braking the trailer based on the braking torque.

[0005] Further, the step of establishing a state observer corresponding to the tractor and the trailer based on the speed v1 of the tractor and the speed v2 of the trailer, and calculating the acceleration a1 of the tractor and the acceleration a2 of the trailer based on the state observer corresponding to the tractor and the trailer, includes: establishing a first state observer corresponding to the tractor based on the speed v1 of the tractor, and calculating the acceleration a1 of the tractor based on the first state observer of the tractor; establishing a second state observer corresponding to the trailer based on the speed v2 of the trailer, and calculating the acceleration a2 of the trailer based on the second state observer of the trailer.

[0006] Furthermore, the braking method further includes, prior to:

[0007] Based on the constant acceleration model of a vehicle, the speed v1 and acceleration a1 of the tractor are selected as state variables, and the first state observer of the corresponding tractor is established:

[0008]

[0009]

[0010] in, This represents the state variables observed by the first state observer. v1 represents the first derivative of the state variable observed by the first state observer, and v1 represents the acquired vehicle speed. l represents the vehicle speed observed by the first-state observer. 11 and l 12 The feedback gain of the first-state observer, the tractor acceleration a1 and Consistent; Based on the constant acceleration model of a vehicle, the speed v2 and acceleration a2 of the tractor are selected as state variables, and a second state observer corresponding to the trailer is established:

[0011]

[0012]

[0013] in, This represents the state variables observed through the second state observer. v1 represents the first derivative of the state variable observed by the second state observer, and v2 represents the acquired vehicle speed. l represents the vehicle speed observed by the second-state observer. 21 and l 22 The feedback gain of the second-state observer, the tractor acceleration a2 and Consistent.

[0014] Further, determining whether the brake pedal travel s meets the first preset condition and / or whether the acceleration a1 of the tractor meets the second preset condition includes: determining whether the brake pedal travel s is greater than a threshold and / or whether the acceleration a1 of the tractor is less than 0.

[0015] Furthermore, the braking torque on the rear trailer is calculated based on the acceleration of the tractor and the trailer, including: calculating the deviation value based on the acceleration a1 of the tractor and the acceleration a2 of the trailer, and then using the deviation value as the input of the controller, which outputs the braking torque T.

[0016] Secondly, the present invention also provides a retrofit trailer synchronous braking device, comprising: a first processing module for acquiring the speed v1 of the tractor, the speed v2 of the trailer, and the brake pedal travel s; a second processing module for calculating the acceleration a1 of the tractor and the acceleration a2 of the trailer based on the speed v1 of the tractor and the speed v2 of the trailer using a state observer; and a third processing module for determining whether the brake pedal travel s meets a first preset condition and / or whether the acceleration a1 of the tractor meets a second preset condition. If the conditions are met, the braking torque applied to the trailer is determined based on the deviation between the acceleration a1 of the tractor and the acceleration a2 of the trailer, and the trailer is braked according to the braking torque.

[0017] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the rear-mounted trailer synchronous braking method as described in any of the above.

[0018] Fourthly, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the post-trailer synchronous braking method as described in any of the above.

[0019] Fifthly, the present invention also provides a tractor unit, including a computer program, characterized in that, when the computer program is executed by a processor, it implements the steps of the synchronous braking method for the rear-mounted trailer as described in any of the above.

[0020] The present invention provides a method, device, equipment, and medium for synchronous braking of a retrofitted trailer, which has the following advantages: by acquiring the speed of the tractor vehicle and the trailer and the brake pedal travel s, the acceleration of the tractor vehicle and the trailer is calculated in real time using an observer. Then, it is determined whether the brake pedal travel s and / or the acceleration of the tractor vehicle meet the preset conditions. If they do, the braking torque is calculated based on the acceleration of the tractor vehicle and the trailer, and the braking torque is output through a linear solenoid valve. Thus, without relying on an accelerometer, the braking force of the tractor vehicle and the trailer vehicle is matched, thereby improving driving safety and comfort. Moreover, the output braking torque is linearly adjustable. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0022] Figure 1 This is a flowchart illustrating some embodiments of the post-installation trailer synchronous braking method provided by the present invention;

[0023] Figure 2 This is a schematic diagram of an application scenario of the synchronous braking method for a rear-mounted trailer provided by the present invention;

[0024] Figure 3 This is a schematic diagram of some embodiments of the retrofitted trailer synchronous braking device provided by the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] It should also be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings. Unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0027] It should be noted that the concepts of "first" and "second" mentioned in this invention are only used to distinguish different devices, modules or units, and are not used to limit the order of functions performed by these devices, modules or units or their interdependencies.

[0028] It should be noted that the terms "a" and "a plurality of" used in this invention are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".

[0029] The names of the messages or information exchanged between the multiple devices in the embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of these messages or information.

[0030] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0031] Please see Figure 1, Figure 1 This is a flowchart illustrating some embodiments of the synchronous braking method for retrofitted trailers provided by the present invention. For example... Figure 1 As shown, the method includes the following steps:

[0032] Step 1: Obtain the speed v1 of the tractor, the speed v2 of the trailer, and the brake pedal travel s.

[0033] As an example, the tractor speed v1 and brake pedal travel s can be obtained via the CAN bus, and the trailer speed v2 can be obtained via a speed sensor installed on the trailer.

[0034] Step 2: Establish a state observer corresponding to the tractor and trailer based on the speed v1 of the tractor and the speed v2 of the trailer, and calculate the acceleration a1 of the tractor and the acceleration a2 of the trailer based on the state observer corresponding to the tractor and trailer.

[0035] In some embodiments, a state observer for the tractor can be established based on the speed v1 of the tractor, and the acceleration a1 of the tractor can be calculated based on the state observer of the tractor; a state observer for the trailer can be established based on the speed v2 of the trailer, and the acceleration a2 of the trailer can be calculated based on the state observer of the trailer.

[0036] As an example, the process of building a state observer can refer to the following steps:

[0037] (1) Based on the constant acceleration model of a car, v = at, v and a are selected as state variables x and v as output variable y;

[0038]

[0039] (2) Based on modern control theory, the following state-space equations are established:

[0040]

[0041] y = [1 0] * x = C * x Formula (2)

[0042] in, It represents the derivative of the state variable x.

[0043] (3) The observability matrix of the system is calculated based on A and C from (2):

[0044]

[0045] The rank of N is 2, therefore the above system is observable.

[0046] (4) Based on the observability of the above system, the following state observer is established:

[0047]

[0048]

[0049] Formula (4) is the state observer, where, This represents the state variables observed by the state observer. Let l1 and l2 represent the derivatives of the observed state variables, l1 and l2 represent the feedback gain of the observer, and v be the actual velocity obtained in step 1. This represents the output variable observed by the state observer (i.e., the velocity observed by the state observer).

[0050] (5) l1 and l2 in the state observer can be obtained by the following method:

[0051] The difference between formula (2) and formula (4) yields the error equation between the actual state variable and the observed state variable:

[0052]

[0053] in

[0054] Let v = y = C*x and Substituting into the above equation and simplifying, we get:

[0055]

[0056] By adjusting the feedback gains l1 and l2, the solution to the above error equation can be made to converge to zero, thereby making the observer's state variables... Track the actual state variable x.

[0057] Referring to the above process, based on the constant acceleration model of a vehicle, the speed v1 and acceleration a1 of the tractor can be selected as state variables to establish the first state observer for the corresponding tractor. The formula for the first state observer is:

[0058]

[0059]

[0060] in, This represents the state variables observed by the first state observer. v1 represents the first derivative of the state variable observed by the first state observer, and v1 represents the acquired vehicle speed. l represents the vehicle speed observed by the first-state observer. 11 and l 12 The feedback gain represents the first-state observer's value, due to the state variables. The actual state variable x1 is tracked, and therefore calculated using formula (7). This refers to the actual v1 value and the tractor acceleration a1 value;

[0061] Based on the constant acceleration model of the vehicle, the speed v2 and acceleration a2 of the tractor are selected as state variables, and a second state observer for the corresponding trailer is established. The formula for the second state observer is:

[0062]

[0063]

[0064] in, This represents the state variables observed through the second state observer. v1 represents the first derivative of the state variable observed by the second state observer, and v2 represents the acquired vehicle speed. l represents the vehicle speed observed by the second-state observer. 21 and l 22 The feedback gain of the second-state observer is due to the state variable. The actual state variable x2 is tracked, and therefore calculated using formula (8). This refers to the actual v2 value and the tractor acceleration a2 value.

[0065] Step 3: Determine whether the brake pedal travel s meets the first preset condition and / or whether the acceleration a1 of the tractor meets the second preset condition. If they meet the conditions, determine the braking torque applied to the trailer based on the deviation between the acceleration a1 of the tractor and the acceleration a2 of the trailer, and brake the trailer according to the braking torque.

[0066] In some embodiments, the deviation value can be calculated based on the acceleration a1 of the tractor and the acceleration a2 of the trailer, and then the deviation value can be used as the input of the controller, which outputs the braking torque T.

[0067] In an application scenario, such as Figure 2 As shown, after observing acceleration, judging braking action, and calculating braking torque based on vehicle speed and braking distance, the controller outputs braking torque T. Then, a control signal u is obtained by looking up a pre-calibrated table based on the braking torque. The control signal u is applied to a DC power supply, which outputs a voltage with variable amplitude. This voltage is then applied to a linear solenoid valve. A PI controller can be selected as the controller.

[0068] In some embodiments, the first preset condition is whether the braking stroke s is greater than a threshold; the second preset condition is whether the acceleration a1 of the tractor is less than 0, and the braking action can be judged based on the first and second preset conditions.

[0069] Please see Figure 3 , Figure 3 These are schematic diagrams illustrating the structure of some embodiments of the retrofitted trailer synchronous braking device provided by the present invention. As an implementation of the methods shown in the above figures, the present invention also provides some embodiments of the retrofitted trailer synchronous braking device, which are similar to... Figure 1 The embodiments of some of the methods shown correspond to this, and the device can be applied to a variety of electronic devices.

[0070] like Figure 3 As shown, in some embodiments, the retrofit trailer synchronous braking device 400 includes a first processing module 301, a second processing module 302, and a third processing module 303: the first processing module is used to acquire the speed v1 of the tractor, the speed v2 of the trailer, and the brake pedal travel s; the second processing module is used to calculate the acceleration a1 of the tractor and the acceleration a2 of the trailer based on the speed v1 of the tractor and the speed v2 of the trailer using a state observer; the third processing module is used to determine whether the brake pedal travel s meets a first preset condition and / or whether the acceleration a1 of the tractor meets a second preset condition. If they meet, the braking torque applied to the trailer is determined based on the deviation between the acceleration a1 of the tractor and the acceleration a2 of the trailer, and the trailer is braked according to the braking torque.

[0071] In some optional implementations of the embodiments, the second processing module is further configured to establish a first state observer corresponding to the tractor based on the speed v1 of the tractor, calculate the acceleration a1 of the tractor based on the first state observer of the tractor; establish a second state observer corresponding to the trailer based on the speed v2 of the trailer, and calculate the acceleration a2 of the trailer based on the second state observer of the trailer.

[0072] In some optional implementations of the embodiments, based on the constant acceleration model of the vehicle, the speed v1 and the vehicle acceleration a1 of the tractor are selected as state variables to establish a first state observer for the corresponding tractor:

[0073]

[0074]

[0075] in, This represents the state variables observed by the first state observer. v1 represents the first derivative of the state variable observed by the first state observer, and v1 represents the acquired vehicle speed. l represents the vehicle speed observed by the first-state observer. 11 and l 12 The feedback gain of the first-state observer, the tractor acceleration a1 and Consistent;

[0076] Based on the constant acceleration model of the vehicle, the speed v2 and the vehicle acceleration a2 of the tractor are selected as state variables, and a second state observer corresponding to the trailer is established:

[0077]

[0078]

[0079] in, This represents the state variables observed through the second state observer. v1 represents the first derivative of the state variable observed by the second state observer, and v2 represents the acquired vehicle speed. l represents the vehicle speed observed by the second-state observer. 21 and l 22 The feedback gain of the second-state observer, the tractor acceleration a2 and Consistent.

[0080] In some optional implementations of embodiments, the third processing module is further configured to determine whether the brake pedal travel s is greater than a threshold and / or whether the acceleration a1 of the tractor is less than 0.

[0081] In some optional implementations, a deviation value is calculated based on the acceleration a1 of the tractor and the acceleration a2 of the trailer, and then this deviation value is used as the input to the controller, which outputs the braking torque T.

[0082] It is understandable that the modules described in this device are consistent with the reference. Figure 1 The steps in the described method correspond to each other. Therefore, the operations, features, and beneficial effects described above for the method also apply to the device and the modules and units contained therein, and will not be repeated here.

[0083] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0084] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synchronous braking of a retrofitted trailer, characterized in that, Applied to braking of a tractor-trailer, the braking methods include: Step 1, obtain the speed of the tractor unit. trailer speed and brake pedal travel ; Step 2, based on the speed of the tractor and the speed of the trailer Establish state observers corresponding to the tractor and trailer, and calculate the acceleration of the tractor based on the state observers corresponding to the tractor and trailer. And the acceleration of the trailer ; Step 3: Determine the brake pedal travel. Does the first preset condition and / or the acceleration of the tractor be met? Does the second preset condition meet? If so, then based on the acceleration of the tractor... And the acceleration of the trailer The deviation value determines the braking torque applied to the trailer, and the trailer is braked according to this braking torque; According to the speed of the tractor and the speed of the trailer Establish state observers corresponding to the tractor and trailer, and calculate the acceleration of the tractor based on the state observers corresponding to the tractor and trailer. And the acceleration of the trailer ,include: According to the speed of the tractor Establish a first state observer for the corresponding tractor vehicle, and calculate the acceleration of the tractor vehicle based on the first state observer. ; According to the speed of the trailer Establish a second state observer for the corresponding trailer, and calculate the trailer's acceleration based on the second state observer. ; The braking method is preceded by: Based on the constant acceleration model of the vehicle, the speed of the tractor is selected. Vehicle acceleration of the tractor As a state variable, establish the first state observer for the corresponding tractor: ； ； in, This represents the state variables observed by the first state observer. This represents the first derivative of the state variable observed by the first-state observer. This represents the speed of the acquired vehicle. This represents the vehicle speed observed by the first-state observer. and The feedback gain of the first-state observer, and the acceleration of the tractor. Consistent; Based on the constant acceleration model of the vehicle, the speed of the tractor is selected. Vehicle acceleration of the tractor As a state variable, establish a second state observer for the corresponding trailer: ； ； in, This represents the state variables observed through the second state observer. This represents the first derivative of the state variable observed by the second-state observer. This represents the speed of the acquired vehicle. This represents the vehicle speed observed by the second-state observer. and The feedback gain of the second-state observer, and the acceleration of the tractor. and Consistent.

2. The method for synchronous braking of a rear-mounted trailer according to claim 1, characterized in that, Determine whether the brake pedal travel s meets the first preset condition and / or the acceleration of the tractor. Whether the second preset condition is met includes: Determine whether the brake pedal travel s is greater than a threshold and / or the acceleration of the tractor. Is it less than 0? 3. The method for synchronous braking of a rear-mounted trailer according to claim 1, characterized in that, The braking torque on the rear trailer is calculated based on the acceleration of the tractor and trailer, including: According to the acceleration of the tractor And the acceleration of the trailer The deviation value is calculated, and then this deviation value is used as the input to the controller, which outputs the braking torque. .

4. A rear-mounted trailer synchronous braking device, characterized in that, include: The first processing module is used to obtain the speed of the tractor. trailer speed and brake pedal travel ; The second processing module is used to process data based on the state observer and the speed of the tractor. and the speed of the trailer Calculate the acceleration of the tractor And the acceleration of the trailer ; It is also used to determine the speed of the tractor. and the speed of the trailer Establish state observers corresponding to the tractor and trailer, and calculate the acceleration of the tractor based on the state observers corresponding to the tractor and trailer. And the acceleration of the trailer ,include: According to the speed of the tractor Establish a first state observer for the corresponding tractor vehicle, and calculate the acceleration of the tractor vehicle based on the first state observer. ; According to the speed of the trailer Establish a second state observer for the corresponding trailer, and calculate the trailer's acceleration based on the second state observer. ; Based on the constant acceleration model of the vehicle, the speed of the tractor is selected. Vehicle acceleration of the tractor As a state variable, establish the first state observer for the corresponding tractor: ； ； in, This represents the state variables observed by the first state observer. This represents the first derivative of the state variable observed by the first-state observer. This represents the speed of the acquired vehicle. This represents the vehicle speed observed by the first-state observer. and The feedback gain of the first-state observer, and the acceleration of the tractor. Consistent; Based on the constant acceleration model of the vehicle, the speed of the tractor is selected. Vehicle acceleration of the tractor As a state variable, establish a second state observer for the corresponding trailer: ； ； in, This represents the state variables observed through the second state observer. This represents the first derivative of the state variable observed by the second-state observer. This represents the speed of the acquired vehicle. This represents the vehicle speed observed by the second-state observer. and The feedback gain of the second-state observer, and the acceleration of the tractor. and Consistent; The third processing module is used to determine the brake pedal travel. Does the first preset condition and / or the acceleration of the tractor be met? Does the second preset condition meet? If so, then based on the acceleration of the tractor... And the acceleration of the trailer The deviation value determines the braking torque applied to the trailer, and the trailer is braked according to this braking torque.

5. An electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the post-trailer synchronous braking method as described in any one of claims 1 to 3.

6. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the rear-mounted trailer synchronous braking method as described in any one of claims 1 to 3.

7. A tractor unit, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the post-trailer synchronous braking method as described in any one of claims 1 to 3.

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