Method and device for adjusting a CAN communication model

Abstract

A method for adjusting a CAN communication model, the method comprising: Measuring a CAN signal waveform; Dividing the CAN signal waveform into a steady period and a dynamic period; Determine a parameter for the continuous period; Determining a parameter for the dynamic period; Modeling a CAN line using the steady period parameter and the dynamic period parameter; and Performing an error analysis on the CAN line.

Description

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to Korean Patent Application No. 10-2015-0030253, filed on March 4, 2015. BACKGROUND OF THE DISCLOSURETechnical Field

[0002] The present disclosure relates generally to a method and apparatus for tuning a controller area network (CAN) communication model, and more particularly to a method and apparatus for tuning a CAN communication model using data obtained by measuring a model and a parameter for a high-speed CAN physical layer simulation. State of the art

[0003] Various electronic systems are installed and used in recently developed vehicles. Such electronic systems include real-time control applications associated with a power trunk opening, an electric mirror adjustment device, a rain detector, a sunroof, a weather management device, power windows, seat adjustment devices, a powertrain, stability control, an anti-lock braking system (ABS), traction control, an active suspension, an engine management device, the Internet, a gear shift, multimedia devices such as a digital television (TV), and the like.

[0004] Typically, many cables are required for a wiring device used to connect the above electronic systems, and such cables account for a significant portion of a vehicle's weight and manufacturing cost. Accordingly, all of these systems can be connected to a common network bus in the vehicle, similar to a method for connecting desktop computers (PCs) in an office, thereby reducing the number of wires in the vehicle and reducing manufacturing costs. This network is referred to as a controller area network (CAN).

[0005] However, there is a problem that a parameter needs to be measured using a precision measuring instrument to build the conventional high-speed CAN physical layer simulation model.

[0006] JP 2007-201697 A relates to a branch connector, and more particularly, to the provision of a branch connector disposed in a branch portion of a communication line for in-vehicle multiplex communication, which can perform stable communication between corresponding communication devices by preventing ringing that occurs upon reflection in a stub line formed by branching. In the branch connector, a communication error can be sufficiently reduced by suppressing waveform distortion. SUMMARY OF REVELATION

[0007] Accordingly, the present disclosure relates to a method and apparatus for adjusting (tuning) a CAN communication model that substantially obviates one or more problems due to limitations and disadvantages of the related art. An object of the present disclosure is to provide a method and apparatus for adjusting a CAN communication model, measuring a CAN signal waveform, and adjusting a parameter constituting a CAN line using the CAN signal waveform.

[0008] Additional advantages, objects, and features of the disclosure will be set forth in part in the description that follows, and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the disclosure. The objects and other advantages of the disclosure may be realized and obtained by the structure particularly pointed out in the description and claims, as well as the accompanying drawings.

[0009] In accordance with embodiments of the present disclosure, a method for adjusting a CAN communication model includes: measuring a CAN signal waveform; dividing (splitting, dividing) the CAN signal waveform into a steady period and a dynamic period; determining a parameter for the steady period; determining a parameter for the dynamic period; modeling a CAN line using the steady period parameter and the dynamic period parameter; and performing fault analysis on the CAN line.

[0010] The steady period may be a period in which a change in the CAN waveform is smaller than a predetermined amount, and the dynamic period may be a period in which a change in the CAN signal waveform is greater than or equal to the predetermined amount.

[0011] Determining the steady period parameter may include: acquiring an average voltage value of the steady period; acquiring a transmit / receive voltage matrix using the average voltage value; acquiring a resistance distribution matrix using the transmit / receive voltage matrix; performing a simulation using the resistance distribution matrix; and determining whether the resistance distribution matrix has changed based on the performed simulation.

[0012] Performing the simulation may include performing the simulation further using a theoretical inductance and a theoretical capacitance.

[0013] Determining the dynamic period parameter may include: detecting a rise time and a fall time of the dynamic period; detecting a dynamic characteristic matrix using the rise time and the fall time; detecting an inductance and capacitance distribution matrix using the dynamic characteristic matrix; performing a simulation using the inductance and capacitance distribution matrix; and determining whether the inductance and capacitance distribution matrix has changed based on the performed simulation.

[0014] Performing the simulation may include performing the simulation further using the resistance distribution matrix.

[0015] The method may further include updating the steady period parameter and the dynamic period parameter.

[0016] According to embodiments of the present disclosure, an apparatus for adjusting a CAN communication model includes: a measuring unit that measures a CAN signal waveform; a parameter unit that divides the CAN signal waveform into a steady period and a dynamic period, determines a parameter for the steady period, and determines a parameter for the dynamic period; a modeling unit that models a CAN line using the parameter for the steady period and the parameter for the dynamic period; and a simulation unit that performs failure analysis on the CAN line.

[0017] The steady period may be a period in which a change in the CAN signal waveform is less than a predetermined amount, and the dynamic period may be a period in which a change in the CAN signal waveform is greater than or equal to the predetermined amount.

[0018] The parameter unit can acquire a steady-state voltage average value, acquire a transmit / receive voltage matrix using the voltage average value, and acquire a resistance distribution matrix using the transmit / receive voltage matrix. The simulation unit can perform a simulation using the resistance distribution matrix and determine whether the resistance distribution matrix has changed based on the performed simulation.

[0019] The simulation unit can further perform the simulation using a theoretical inductance and a theoretical capacitance.

[0020] The parameter unit can acquire a rise time and a fall time of the dynamic period, acquire a dynamic characteristic matrix using the rise time and a fall time, and acquire an inductance and capacitance distribution matrix using the dynamic characteristic matrix. The simulation unit can perform a simulation using the inductance and capacitance distribution matrix and determine whether the inductance and capacitance distribution matrix has changed based on the performed simulation.

[0021] The simulation unit can continue to perform the simulation using the resistance distribution matrix.

[0022] The device may further include a parameter database that updates the steady period parameter and the dynamic period parameter.

[0023] According to embodiments of the present disclosure, a non-transitory, computer-readable medium containing program instructions for adjusting a CAN communication model includes: program instructions that measure a CAN signal waveform; program instructions that divide the CAN signal waveform into a steady period and a dynamic period; program instructions that determine a parameter for the steady period; program instructions that determine a parameter for the dynamic period; program instructions that model a CAN line using the steady period parameter and the dynamic period parameter; and program instructions that perform fault analysis on the CAN line.

[0024] It should be understood that both the foregoing general description and the following detailed description of the present disclosure are exemplary and explanatory and are intended to provide further explanation of the claimed disclosure. BRIEF DESCRIPTION OF THE ILLUSTRATIONS

[0025] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiments of the disclosure and, together with the description, serve to explain the principle of the disclosure. Fig. 1 is a diagram showing an example of a CAN line adjusting device to which the present disclosure is applied; Fig. 2 is a diagram showing an example of a procedure for adjusting a CAN line according to embodiments of the present disclosure; Fig. 3 is a diagram showing an example of adjusting a steady period of a waveform according to embodiments of the present invention; Fig. 4 is a diagram showing an example of adjusting a dynamic period according to embodiments of the present invention; and Fig. 5 is a diagram showing an example of updating a parameter database of a parameter whose adjustment has been completed according to embodiments of the present invention. DETAILED DESCRIPTION OF REVELATION

[0026] Terms or words used herein should not be limited to their dictionary meaning and must be interpreted with the meaning corresponding to technical aspects of the embodiments of the present disclosure under the principle that the inventor can define the terms appropriately to best describe the embodiments of the present disclosure. Accordingly, elements described in the specification and shown in the accompanying drawings are merely examples and are not used to express all technical aspects, and thus, it should be understood by those skilled in the art that various equivalents and changes in form and details may be made herein when the application is filed.

[0027] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. As used herein, the singular forms "a," "an," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should further be understood that the terms "comprises" or "comprising," when used in this specification, specify the presence of the recited features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0028] It should be understood that the term "vehicle" or "car" or similar terms used herein include motor vehicles in general, such as passenger automobiles, including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft, including a variety of boats and ships, aircraft, and the like, and include hybrid vehicles, electric vehicles, plug-in hybrid vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than oil). A hybrid vehicle described herein is a vehicle that has two or more power sources, for example, both gasoline-powered and electric-powered vehicles.

[0029] It should additionally be understood that one or more of the following methods, or aspects thereof, may be performed by at least one control unit. The term "control unit" may refer to a hardware device that includes a memory and a processor. The memory is configured to store program instructions, and the processor is specifically programmed to execute the program instructions to perform one or more processes, which are further described below. Furthermore, it should be understood that the following methods may be performed by a device that includes the control unit together with one or more other components, as understood by one of ordinary skill in the art.

[0030] The control unit of the present disclosure may further be embodied as a non-transitory, computer-readable medium on a computer-readable medium containing executable program instructions executed by a processor, controller, or the like. Examples of the computer-readable medium include, but are not limited to, ROM, RAM, compact disc (CD)-ROMs, magnetic tapes, floppy disks, flash memory, smart cards, and optical data storage devices. The computer-readable recording medium may also be distributed in a network coupled to computer systems such that the computer-readable medium is stored and executed in a distributed manner, for example, through a telematics server and a CAN network.

[0031] With reference to the disclosed embodiments, Fig. 1 is a diagram showing an example of a CAN line adjusting device to which the present disclosure is applied.

[0032] As in Fig. 1, a measurement unit 110 measures a CAN signal waveform. A tuning tool 120 may acquire an actually measured waveform and CAN topology information and tune a parameter using the actually measured waveform and the CAN topology information. In addition, the tuning tool 120 may tune (adjust) the parameter using a simulation result of a simulation unit 150. The CAN topology information may include information about a method for connection between elements of CAN communication.

[0033] A parameter unit 130 may display a parameter value by the tuning result determined by the tuning tool 120. The tuning result may be a device value or an estimated value of each component of a CAN line model circuit, and each component may include at least one of a current source, a resistance R, an inductance (coil) L, and a capacitance (capacitor) C.

[0034] A model unit 140 may form a CAN line model circuit using a parameter value configured in each line.

[0035] The simulation unit 150 may perform a simulation to obtain the simulation result. The simulation result may include error information based on the transmitted and received information of the CAN communication.

[0036] A user interface (UI) 160 may allow a user to view a current CAN line model and check whether tuning is progressing.

[0037] An example of analyzing an actually measured waveform is described below.

[0038] Fig. 2 is a diagram showing an example of a procedure for adjusting a CAN line according to embodiments of the present disclosure.

[0039] When measuring a CAN communication signal waveform, a period of a CAN communication signal waveform can be classified. The period of the CAN communication signal waveform can be divided into a steady (constant, smooth, uniform) period and a dynamic period. The steady period may indicate a period having a signal with a constant magnitude, and the dynamic period may indicate a period having a signal that changes noticeably (significantly). The steady period and the dynamic period can be distinguished according to whether a change in a CAN signal waveform is equal to or smaller than a predetermined magnitude.

[0040] In the steady period, a resistance can be derived using a transmit / receive voltage of a current portion of a waveform. The resistance can include all the resistances distributed along a line, a connector, and an electronic control unit (ECU) of a line. Additionally, a resistance per unit length can be extracted for the line as a target parameter.

[0041] In the dynamic period, inductance and capacitance can be derived through sections of rising and falling periods in which a waveform changes. For a wiring, inductance and capacitance can be extracted per unit quantity as target parameters, while for an ECU, only capacitance can be derived.

[0042] A primary parameter estimation may be performed on a continuous period signal (S220). The primary parameter estimation may be an estimate of the continuous period signal and may refer to a preferred estimate of a parameter that affects a current component of the continuous period. The primary parameter estimation is described in detail below with reference to Fig. 3 described.

[0043] A secondary parameter estimation may be performed on a steady period signal and / or a dynamic period signal on which the primary parameter estimation was performed (S230). The secondary parameter estimation may be an estimation with respect to a steady period or a dynamic period and may refer to a parameter that affects components other than a current component. The secondary parameter estimation is described in detail below with reference to Fig. 4 explained.

[0044] A CAN line can be modeled by the estimated parameter, and an error of the modeled CAN line can be analyzed (S240). An error range can be determined by performing probabilistic analysis on the parameter estimated by the primary parameter estimation and the secondary parameter estimation. If the determined error range is equal to or greater than a predetermined threshold, the primary parameter estimation and the secondary parameter estimation can be performed again.

[0045] If the specified error range is equal to or smaller than a predetermined value, the specified parameter can be applied (S250).

[0046] A method for adjusting a continuous period is described below.

[0047] Fig. 3 is a diagram showing an example of adjusting a steady period of a waveform according to embodiments of the present disclosure.

[0048] An average value (mean) of voltages of the steady period can be acquired (S310). The average value can be an arithmetic mean, a geometric mean, a harmonic mean, or a root mean square (RMS). Prestored adjustment information can be used to acquire an average value of voltages. The prestored adjustment information will be described again below.

[0049] A transmit / receive voltage distribution matrix can be acquired using the average of the voltages (S320).

[0050] A resistance distribution matrix can be adjusted using the transmit / receive voltage distribution matrix (S330). The resistance distribution matrix can be adjusted by setting a theoretical value as an initial value and using the transmit / receive voltage distribution matrix.

[0051] A simulation can be performed using the adjusted resistance distribution matrix (S340). The simulation can be performed using a resistance from the resistance distribution matrix, a theoretical inductance, and a theoretical capacitance. The simulation can be performed to analyze a CAN line fault using the current resistance distribution matrix.

[0052] The error and a predetermined value may be compared (S350). If the error is greater than the predetermined value, an operation S330 for acquiring the resistance distribution matrix may be performed again. Operation S330 may be performed until the error becomes smaller than the predetermined value. On the other hand, if the error is smaller than the predetermined value, the adjustment may be terminated.

[0053] A method for adjusting a dynamic period is described below.

[0054] Fig. 4 is a diagram illustrating an example of adjusting a dynamic period according to embodiments of the present disclosure.

[0055] A rise time, fall time, and overshoot of a waveform of the dynamic period can be detected (S410). Prestored tuning information can be used to detect the rise time, fall time, and overshoot of the waveform. The prestored tuning information is described again below.

[0056] A dynamic characteristic matrix can be acquired using the rise time, fall time and overshoot (S420).

[0057] An inductance and capacitance distribution matrix can be adjusted using the dynamic characteristic matrix (S430). The inductance and capacitance distribution matrix can be adjusted by setting theoretical inductance and capacitance values ​​as initial values ​​and using the dynamic characteristic matrix.

[0058] A simulation can be performed using the adjusted inductance and capacitance distribution matrix (S440). The simulation can be performed using the inductance and capacitance distribution matrix and the adjusted inductance in Fig. 3. The simulation can be performed to analyze a CAN line fault using the inductance and capacitance distribution matrix.

[0059] The error and a predetermined value may be compared (S450). If the error is greater than a predetermined value, an operation S430 for acquiring the inductance and capacitance distribution matrix may be performed again. Operation S430 may be performed until the error is smaller than the predetermined value. On the other hand, if the error is smaller than the predetermined value, the adjustment is terminated.

[0060] The following describes an example of updating a parameter database using a parameter whose tuning has been completed.

[0061] Fig. 5 is a diagram describing an example of updating a parameter database using a parameter whose adjustment has been completed according to embodiments of the present disclosure.

[0062] As in Fig. 5, the parameter database can be updated by adding the result obtained by performing parameter adjustment as described with reference to Fig. 3 and Fig.4, and the result obtained by performing parameter tuning in a plurality of vehicle models (i.e., vehicle model 1 to vehicle model N) to the parameter database. The updated parameter database can be used in future parameter tuning to provide pre-stored tuning information.

[0063] As described above, according to the present disclosure, parameter tuning costs can be reduced with low-cost equipment and tuning periods. In addition, technology required during a tuning procedure can be used as a tool, allowing anyone to easily perform the tuning procedure. Dependence on measurement error can also be reduced, allowing even a parameter that is difficult to accurately measure to be estimated. Furthermore, various tables can be accumulated to test CAN communication performance without actual measurement.

[0064] It will be apparent to those skilled in the art that various modifications and variations of the present disclosure can be made without departing from the scope of the disclosure. Thus, it is intended that the present disclosure cover the modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalents.

Claims

[1] A method for adjusting a CAN communication model, the method comprising: Measuring a CAN signal waveform; Dividing the CAN signal waveform into a steady period and a dynamic period; Determine a parameter for the continuous period; Determining a parameter for the dynamic period; Modeling a CAN line using the steady period parameter and the dynamic period parameter; and Performing an error analysis on the CAN line. [2] The method of claim 1, wherein: the steady period is a period in which a change in the CAN signal waveform is smaller than a predetermined size, and the dynamic period is a period in which a change in the CAN signal waveform is greater than or equal to the predetermined size. [3] The method of claim 1 or 2, wherein determining the continuous period parameter comprises: Recording a voltage average of the continuous period; Acquiring a transmit / receive voltage matrix using the average voltage; Acquiring a resistance distribution matrix using the transmit / receive voltage matrix; Performing a simulation using the resistance distribution matrix; and Determine whether the resistance distribution matrix has changed based on the simulation performed. [4] The method of claim 3, wherein performing the simulation comprises: Continue to perform the simulation using a theoretical inductance and a theoretical capacitance. [5] A method according to any preceding claim, wherein determining the dynamic period parameter comprises: Detecting a rise time and a fall time of the dynamic period; Acquiring a dynamic characteristic matrix using the rise time and the fall time; Obtaining an inductance and capacitance distribution matrix using the dynamic characteristic matrix; Performing a simulation using the inductance and capacitance distribution matrix; and determining whether the inductance and capacitance distribution matrix has changed based on the performed simulation. [6] The method of claim 5, wherein performing the simulation comprises: Continue to perform the simulation using the resistance distribution matrix. [7] A method according to any preceding claim, further comprising updating the steady period parameter and the dynamic period parameter. [8] Device for adjusting a CAN communication model, the device comprising: a measuring unit for measuring a CAN signal waveform; a parameter unit for dividing the CAN signal waveform into a steady period and a dynamic period, determining a parameter for the steady period and determining a parameter for the dynamic period; a modeling unit for modeling a CAN line using the steady period parameter and the dynamic period parameter; and a simulation unit for performing an error analysis on the CAN line. [9] Device according to claim 8, wherein: the steady period is a period in which a change in the CAN signal waveform is smaller than a predetermined size, and the dynamic period is a period in which a change in the CAN signal waveform is greater than or equal to the predetermined size. [10] Device according to claim 8 or 9, wherein: the parameter unit acquires a voltage average value of the steady period, acquires a transmit / receive voltage matrix using the voltage average value, and acquires a resistance distribution matrix using the transmit / receive voltage matrix; and the simulation unit performs a simulation using the resistance distribution matrix and determines whether the resistance distribution matrix has changed based on the simulation performed. [11] The device according to any one of claims 8-10, wherein the simulation unit further performs the simulation using a theoretical inductance and a theoretical capacitance. [12] Device according to one of claims 8-11, wherein: the parameter unit acquires a rise time and a fall time of the dynamic period, acquires a dynamic characteristic matrix using the rise time and the fall time, and acquires an inductance and capacitance distribution matrix using the dynamic characteristic matrix; and the simulation unit performs a simulation using the inductance and capacitance distribution matrix and determines whether the inductance and capacitance distribution matrix has changed based on the simulation performed. [13] The apparatus of any of claims 8-12, wherein the simulation unit further performs the simulation using the resistance distribution matrix. [14] Apparatus according to any one of claims 8-13, further comprising a parameter database that updates the steady period parameter and the dynamic period parameter. [15] A non-transitory, computer-readable medium containing program instructions for adjusting a CAN communication model, the computer-readable medium comprising: Program instructions that measure a CAN signal waveform; Program instructions that divide the CAN signal waveform into a steady period and a dynamic period; Program instructions that specify a parameter for the continuous period; Program instructions that specify a parameter for the dynamic period; Program instructions that model a CAN line using the steady period parameter and the dynamic period parameter; and Program commands that perform error analysis on the CAN line.

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