Abstract:
The present invention achieves, using simple circuits, timing synchronization among ECUs of an electronic control device which is configured from a driver ECU, a sensor ECU, and an integrated ECU which are connected over a network. This electronic control device is provided with a driver ECU for driving various loads for vehicular control, a sensor ECU for sampling various sensor signals, and an integrated ECU which is connected to the driver ECU and sensor ECU over a network and calculates command values to the various loads in accordance with various sensor data, the electronic control device being characterized in that the driver ECU has timer D for generating internal timing, the sensor ECU has timer S for generating internal timing, and the integrated ECU has timer M serving as a reference for timer D and timer S.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to an electronic control device, and particularly to an electronic control device which includes a driver ECU for driving a load, a sensor ECU for acquiring sensor data, and an integrated ECU for generating a command value to the driver ECU from the sensor data and which is suitable when each of the ECUs is network-connected. 
       BACKGROUND ART 
       [0002]    In recent years, complexity of vehicular control has increased, and functions and the number of IOs of an ECU have increased. In order to eliminate the complexity of the ECU, a configuration has been proposed in which sensor data acquisition and driver functions that are implemented with conventional ECUs are distributed on various sensors as a sensor ECU and a driver ECU and actuators and each ECU is network-connected. 
         [0003]    In such a distributed architecture, a high-precision timing synchronization between ECUs is important in order to perform a high-precision control. In PTL 1, a high-precision timing synchronization is achieved by using a high-speed time division multiple access (TDMA) and compensating timing information in various sensor ECUs and driver ECUs. 
       CITATION LIST 
     Patent Literature 
       [0004]    PTL 1: JP 2004-190662 A 
       SUMMARY OF INVENTION 
     Technical Problem 
       [0005]    The invent ion disclosed in PTL 1 can realize high-precision timing synchronization, but it requires complex network protocol and a microcontroller for performing correction processing on various sensor ECUs and driver ECUs, thus a cost of the entire system is easily increased. 
         [0006]    In view of the above, the present invention intends to provide an electronic control device that uses simple circuits on the side of the network ECU and the driver ECU to realize a timing synchronization of the various ECUs which are network-connected. 
       Solution to Problem 
       [0007]    To achieve the above object, the present invention provides an electronic control device, including: a driver ECU that drives various loads for vehicular control; a sensor ECU that samples various sensor signals; and an integrated ECU that is connected to the driver ECU and the sensor ECU via a network and calculates command values for various loads from various sensor data, wherein the driver ECU includes a timer D for generating internal timing, the sensor ECU includes a timer S for generating internal timing, and the integrated ECU includes a timer M that is a reference of the timer D and the timer S. 
       Advantageous Effects of Invention 
       [0008]    According to the present invention, since a variation of a timer in each ECU is corrected on the side of an integrated ECU, a high-precision timing synchronization of various ECUs can be realized with simple circuits on the side of the network ECU and the driver ECU. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0009]      FIG. 1  is an overall block diagram of an electronic control device according to a first embodiment of the present invention. 
           [0010]      FIG. 2  is a timing chart showing a synchronization method between an integrated ECU and a driver ECU according to the first embodiment of the present invention. 
           [0011]      FIG. 3  is a timing chart showing a synchronization method between the integrated ECU and a sensor ECU according to a second embodiment of the present invention. 
           [0012]      FIG. 4  is a timing chart of data transfer on a network of a plurality of sensor ECUs according to a third embodiment of the present invention. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
       [0013]    Hereinafter, a configuration and an operation of an electronic control device according to a first embodiment of the present invention will be described with reference to  FIGS. 1 and 2 . 
         [0014]      FIG. 1  is an overall block diagram of a current control device according to the first embodiment of the present invention. 
         [0015]    The electronic control device includes a driver ECU ( 4 ) that drives an actuator ( 6 ), a sensor ECU 1  ( 3 ) that samples data from a sensor ( 5 ), a sensor ECU 2  ( 7 ) that samples data from various sensors (not illustrated), a sensor ECU 3  ( 8 ), and an integrated ECU ( 1 ) that calculates command values to the driver ECU ( 4 ) based on various sensor data. Each of the ECUs is connected with a network ( 2 ), and transmits and receives data for control via the network. 
         [0016]    The integrated ECU ( 1 ) includes a threshold value generation unit ( 10 ) for generating a threshold value for indicating timings to the sensor ECU 1  ( 3 ), the sensor ECU 2  ( 7 ), the sensor ECU 3  ( 8 ), and the driver ECU ( 4 ). 
         [0017]    Based on a control algorithm (not illustrated), the threshold value generation unit ( 10 ) generates a threshold value to indicate timing at which the driver ECU ( 4 ) turns on the actuator ( 6 ), and stores the value in a threshold value register MD 1  ( 21 ). 
         [0018]    In addition, based on the control algorithm (not illustrated), the threshold value generation unit ( 10 ) generates a threshold value to indicate timing at which the driver ECU ( 4 ) turns off the actuator ( 6 ), and stores the value in a threshold value register MD 2  ( 22 ). 
         [0019]    In addition, based on the control algorithm (not illustrated), the threshold value generation unit ( 10 ) generates a threshold value to indicate timing at which the sensor ECU 1  ( 3 ) samples data from the sensor ( 5 ), and stores the value in a threshold value register MS ( 23 ). 
         [0020]    In addition, based on the control algorithm (not illustrated), the threshold value generation unit ( 10 ) generates a threshold value to indicate timing at which the sensor ECU 1  ( 3 ) transmits the data on the network ( 2 ), and stores the value in a threshold value register MS 1  ( 23 - 1 ). 
         [0021]    In addition, based on the control algorithm (not illustrated), the threshold value generation unit ( 10 ) generates a threshold value to indicate timing at which the sensor ECU 2  ( 7 ) transmits the data on the network ( 2 ), and stores the value in a threshold value register MS 2  ( 23 - 2 ). 
         [0022]    In addition, based on the control algorithm (not illustrated), the threshold value generation unit ( 10 ) generates a threshold value to indicate timing at which the sensor ECU 3  ( 8 ) transmits the data on the network ( 2 ), and stores the value in a threshold value register MS 3  ( 23 - 3 ). 
         [0023]    The integrated ECU ( 1 ) includes a timer M ( 14 ) which serves as a reference for timing of the present electronic control system. The threshold value generation unit ( 10 ) calculates values using the timer M ( 14 ) as the reference and stores each of the values in each of the threshold value register MD 1  ( 21 ), the threshold value register MD 2  ( 22 ), the threshold value register MS 1  ( 23 - 1 ), the threshold value register MS 2  ( 23 - 2 ), and the threshold value register MS 3  ( 23 - 3 ). 
         [0024]    The integrated ECU ( 1 ) includes a synchronization signal generation unit ( 11 ) that resets the timer M ( 14 ), a timer S 1  ( 35 ) in the sensor ECU 1  ( 3 ), a timer S 2  ( 71 ) in the sensor ECU 2  ( 7 ), a timer S 3  ( 81 ) in the sensor ECU 3  ( 8 ), and a timer D ( 45 ) in the driver ECU ( 4 ) simultaneously and generates timings for capturing their values. The timings from the synchronization signal generation unit ( 11 ) are output to a network IF ( 13 ) via a signal sync ( 19 ), and then output to each of the ECUs via the network ( 2 ). 
         [0025]    A value of the timer M ( 14 ) is captured at the timing indicated by the synchronization signal generation unit ( 11 ), and the captured value is stored in a capture register M ( 15 ). 
         [0026]    Similarly, in the sensor ECU 1  ( 3 ), a value of the timer S 1  ( 35 ) is captured at the timing indicated by the synchronization signal generation unit ( 11 ), and the captured value is stored in a capture register S 1  ( 36 ). The value of the capture register S 1  ( 36 ) is transferred to the capture register MS 1  ( 17 - 1 ) in the integrated ECU ( 1 ) via the network 
         [0027]    Similarly, in the sensor ECU 2  ( 7 ), a value of the timer S 2  ( 71 ) is captured at the timing indicated by the synchronization signal generation unit ( 11 ), and the captured value is stored in a capture register S 2  ( 72 ). The value of the capture register S 2  ( 72 ) is transferred to a capture register MS 2  ( 17 - 2 ) in the integrated ECU ( 1 ) via the network ( 2 ). 
         [0028]    Similarly, in the sensor ECU 3  ( 8 ), a value of the timer S 3  ( 81 ) is captured at the timing indicated the synchronization signal generation unit ( 11 ), and the captured value is stored in a capture register S 3  ( 82 ). The value of the capture register S 3  ( 82 ) is transferred to a capture register MS 3  ( 17 - 3 ) in the integrated ECU ( 1 ) via the network ( 2 ). 
         [0029]    Similarly, in the driver ECU ( 4 ), a value of the timer D ( 45 ) is captured at the timing indicated by the synchronization signal generation unit ( 11 ), and the captured value is stored in a capture register D ( 46 ). The value of the capture register D ( 46 ) is transferred to a capture register MD ( 16 ) in the integrated ECU ( 1 ) via the network ( 2 ). 
         [0030]    In order to correct a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer D ( 45 ) in the driver ECU ( 4 ), a threshold value correction unit ( 12 ) corrects the threshold value according to a formula of a threshold value register MD 1 *=(the capture register D/the capture register M)*the threshold value register MD 1 , and stores the corrected value in the threshold value register MD 1 * ( 25 ). The value of the threshold value register MD 1 * ( 25 ) is transferred to a threshold value register D 1  ( 43 ) in the driver ECU ( 4 ) via the network ( 2 ). 
         [0031]    Similarly, in order to correct a difference in speed between the timer M ( 14 ) in the integrated ECU) and the timer D ( 45 ) in the driver ECU ( 4 ), the threshold value correction unit ( 12 ) corrects the threshold value according to a formula of a threshold value register MD 2 *=(the capture register D/the capture register M)*the threshold value register MD 2 , and stores the corrected value in a threshold value register MD 1 * ( 26 ). The value of the threshold value register MD 1 * ( 26 ) is transferred to a threshold value register D 1  ( 44 ) in the driver ECU ( 4 ) via the network ( 2 ). 
         [0032]    Similarly, in order to correct a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer S 1  ( 35 ) in the sensor ECU 1  ( 3 ), the threshold value correction unit ( 12 ) corrects the threshold value according to a formula of a threshold value register MS*=(a capture register S/the capture register M)*the threshold value register MS, and stores the corrected value in a threshold value register MS* ( 27 ). The value of the threshold value register MS* ( 27 ) is transferred to the threshold value register  5  ( 33 ) in the sensor ECU 1  ( 3 ) via the network ( 2 ). 
         [0033]    Similarly, in order to correct a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer S 1  ( 35 ) in the sensor ECU 1  ( 3 ), the threshold value correction unit ( 12 ) corrects the threshold value according to a formula of a threshold value register MS 1 *=(the capture register S/the capture register M)*the threshold value register MS 1 , and stores the corrected value in a threshold value register MS 1 * ( 27 - 1 ). The value of the threshold value register MS 1 * ( 27 - 1 ) is transferred to a threshold value register S 1  ( 34 ) in the sensor ECU 1  ( 3 ) via the network ( 2 ). 
         [0034]    Similarly, in order to correct a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer S 2  ( 71 ) in the sensor ECU 2  ( 7 ), the threshold value correction unit ( 12 ) corrects the threshold value according to a formula of a threshold value register MS 2 * (the capture register S 2 /the capture register M)*the threshold value register MS 2 , and stores the corrected value in a threshold value register MS 2 * ( 27 - 2 ). The value of the threshold value register MS 2 * ( 27 - 2 ) is transferred to the threshold value register S 2  ( 73 ) in the sensor ECU 2  ( 7 ) via the network ( 2 ). 
         [0035]    Similarly, in order to correct a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer S 3  ( 81 ) in the sensor ECU 3  ( 8 ), the threshold value correction unit ( 12 ) corrects the threshold value according to a formula of a threshold value register MS 3 *=(the capture register S 3 /the capture register M)*the threshold value register MS 3 , and stores the corrected value in a threshold value register MS 3 * ( 27 - 3 ). The value of the threshold value register MS 3 * ( 27 - 3 ) is transferred to a threshold value register S 3  ( 83 ) in the sensor ECU 3  ( 8 ) via the network ( 2 ). 
         [0036]    In the driver ECU ( 4 ), a timing generation unit D ( 42 ) compares values of the threshold value register D 1  ( 43 ) and the timer D ( 45 ), and generates timing to turn on an MOS ( 47 ). Further, the timing generation unit D ( 42 ) compares the values of the threshold value register D 2  ( 44 ) and the timer D ( 45 ), and generates timing to turn off the MOS ( 47 ). As described above, the MOS ( 47 ) is controlled to be turned on and off to drive the actuator ( 6 ). 
         [0037]    In the sensor ECU 1  ( 3 ), a timing generation unit S ( 32 ) compares the values of the threshold value register S ( 33 ) and the timer S ( 35 ), and generates timing at which the AD converter ( 37 ) samples data from the sensor ( 5 ). Further, the timing generation unit S ( 32 ) compares the values of the threshold value register S 1  ( 34 ) and the timer S ( 35 ), and generates timing to send the data to the network ( 2 ). 
         [0038]    Similarly, in the sensor ECU 2  ( 7 ) and the sensor ECU ( 8 ), the timer S 2  ( 71 ), the threshold value register S 2  ( 73 ), the timer S 3  ( 81 ), and the threshold value register S 3  ( 83 ) are used to generate timing to transfer the data to the network ( 2 ). 
         [0039]    Hereinafter, with reference to  FIG. 2 , an operation of driving the actuator ( 6 ) by the electronic control device described with reference to  FIG. 1  will be described. 
         [0040]    In the integrated ECU ( 1 ), timings to turn on and off the actuator ( 6 ) are generated by using the threshold value MD 1  and the threshold value MD 2 . Here, since there is a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer D ( 45 ) in the driver ECU ( 4 ), there is a problem that a timing deviation occurs if the same threshold value is used. Therefore, the threshold value is corrected by the aforementioned method. In this example, the timer D is slower in counting up than the timer M indicated by the dotted line. By correcting the threshold value according to the formula described above, it is possible to generate a waveform similar to the pulse timing based on the timer M on the side of the driver ECU. 
       Second Embodiment 
       [0041]    Hereinafter, a sensor data sampling operation of an electronic control device according to a second embodiment of the present invention will be described with reference to  FIG. 3 . 
         [0042]    In the integrated ECU ( 1 ), a threshold value S and a threshold value S 1  are used to generate timings for sampling a sensor data and transferring the data on the network. Here, since there is a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer S ( 35 ) in the sensor ECU 1  ( 3 ), there is a problem that a timing deviation occurs if the same threshold value is used. Therefore, the threshold value is corrected by the aforementioned method. In this example, the timer S is slower in counting up than the timer M indicated by the dotted line. By correcting the threshold value according to the formula described above, it is possible to generate timings similar to the timings for sampling and transferring the data based on the timer M on the side of the sensor ECU. 
       Third Embodiment 
       [0043]    Hereinafter, a network transfer operation of an electronic control device according to a third embodiment of the present invention will be described with reference to  FIG. 4 . 
         [0044]    In the integrated ECU ( 1 ), the threshold value S 1 , the threshold value S 1 , and a threshold value S 3  are used to generate data transferring timings of the sensor ECU 1 , the sensor ECU 2 , and the sensor ECU 3 . Here, since there is a difference in speed between the timer M ( 14 ) in the integrated ECU ( 1 ) and the timer S 1  ( 35 ), the timer S 2  ( 71 ), and the timer S 3  ( 81 ) in the sensor ECUs, there is a problem that a timing deviation occurs if the same threshold value is used. Therefore, by correcting the threshold value according to the formula described above, it is possible to generate timings similar to the data transmission timings based on the timer M on the side of each of the sensor ECUs. In this example, by transferring the data at equal intervals, a data collision is avoided and the data is transferred with low delay. According to the application of the present invention, a data transfer with low delay is realized with a simple circuit without performing complicated network processing such as collision avoidance and priority determination on the side of the sensor ECU. 
       REFERENCE SIGNS LIST 
       [0000]    
       
           1  integrated ECU 
           2  network 
           3  sensor ECU 1   
           4  driver ECU 
           5  sensor 
           6  actuator 
           7  sensor ECU 2   
           8  sensor ECU 3