Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based upon and claims the benefit of priority from prior Japanese Patent Application No. 2003-290196, filed Aug. 8, 2003, the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a trouble diagnosing device that diagnoses a trouble of a vehicle such as a track or a bus, as the device is coupled with an ECU (electronic control unit) mounted on the vehicle. 
   2. Description of the Related Art 
   As shown in  FIG. 7 , a trouble diagnosing device for an electronic control system of a vehicle is conventionally known. (See, for example, Jpn. Pat. Appln. KOKAI Publication No. 2002-91545.) As shown in  FIG. 7 , a trouble diagnosing device  1  is connected via a communication line  2  to a vehicle-installed ECU  3  (electronic control unit). Various commands are transmitted and received between the trouble diagnosing device  1  and the ECU  3  via the communication line  2 . The ECU  3  has a diagnosis function. The diagnosis function means a self-diagnostic function. More specifically, the ECU  3  monitors input signals from various sensors, actuator and switch, and when some abnormality occurs in an input signal, the ECU  3  makes a memory  4  store the contents of the abnormality (diagnosis code). When a starter switch (not shown) is turned on to start the engine, thus generated diagnosis code is stored in a current trouble information region of the memory  4  as a current diagnosis code in real time. When the starter switch (not shown) is turned off, the diagnosis code stored in the current trouble information region of the memory  4  is transferred to a past trouble information region of the memory  4 , where the transferred code is set as a past diagnosis code, and the current trouble information region is cleared to zero. 
   The trouble diagnosis device  1  includes a display unit  5 , an “S” key  6   a , a “C” key  6   b , a cursor key  7 , an “YES” key  8   a , a “NO” key  8   b  and function keys  9 . 
   The trouble diagnosing device  1  can display a diagnosis code generated while the vehicle is running, on a display unit  5 . 
   For example, when a self-diagnostic mode is set by manipulating a particular key, the trouble diagnosing device  1  transmits to the ECU  3  a command instructing to read the current diagnosis codes stored in the current trouble information region of the memory  4 . Consequently, the current diagnosis codes are displayed on the display unit  5  as shown in  FIG. 8A . The display unit  5  displays a total of 5 diagnosis codes including “11. common rail pressure sensor”. In the case where more than 5 diagnosis codes are actually stored in the current trouble information region of the memory  4 , these codes must be scrolled on the screen by manipulating the cursor key  7 . It should be noted that numeral “11” indicates a diagnosis code. 
   For maintenance, it is necessary to know the past diagnosis codes. To display the past codes, for example, the “S” key  6   a  was assigned for this operation. As the “S” key  6   a  is operated, the trouble diagnosing device  1  transmits to the ECU  3  a command of reading out the past diagnosis codes stored in the past trouble information region of the memory  4  of the ECU  3 . Consequently, the past diagnosis codes are displayed on the display unit  5 . 
   As described above, in order to display past diagnosis codes on the display unit  5 , the key operation described above must be performed, but this operation is laborious and therefore it makes the maintenance work more complicated. 
   Further, for the repair of a broken-down vehicle, not only current diagnosis codes but also past diagnosis codes are important data. Nevertheless, if one mechanic takes a memo of the information of the diagnosis codes displayed on the display unit  5 , and passes it to another mechanic, there results in some cases such confusion that it is not clear as to whether a diagnosis code on the memo indicates a current diagnosis code or a past diagnosis code. When such confusion occurs, it is very difficult to investigate the cause for the trouble. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention has been proposed in consideration of the above-described points, and the object thereof is to provide a trouble diagnosing device with an improved ease of maintenance and repair using diagnosis codes stored in an electronic control device equipped with a diagnostic function and capable of easily investigating the cause for a trouble. 
   According to an aspect of the present invention, there is provided a trouble diagnosing device connectable to an electronic control unit mounted on a vehicle and equipped with a trouble storing unit configured to store current trouble information and past trouble information, the trouble diagnosing device comprising: a display screen configured to display a diagnosed trouble state; and a simultaneous display unit configured to call trouble information stored in the trouble storing unit and make both of the current trouble information and past trouble information at a same time on the display screen. 
   Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be leaned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred embodiments of the invention, and together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
       FIG. 1  is a diagram illustrating connection between a trouble diagnosing device and an ECU according to an embodiment of the present invention; 
       FIG. 2  is a diagram showing a system structure of a personal computer that constitutes the trouble diagnosing device according to the same embodiment; 
       FIGS. 3A and 3B  are diagrams each showing a structure of the trouble storing unit; 
       FIG. 4  is a flowchart briefly illustrating the operation of the trouble diagnosing device according to the same embodiment; 
       FIG. 5  is a diagram showing a startup screen of the trouble diagnosing device according to the same embodiment; 
       FIG. 6  is a diagram showing a self-diagnosis screen of the trouble diagnosing device according to the same embodiment; 
       FIG. 7  is a diagram illustrating a trouble diagnosing device according to a conventional technique; and 
       FIGS. 8A and 8B  are diagrams each showing a display screen of the trouble storing unit according to the conventional technique. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   An embodiment of the present invention will now be described with reference to accompanying drawings.  FIG. 1  is a diagram illustrating connection between the trouble diagnosing device according to this embodiment and an ECU mounted to the vehicle and designed to control the air suspension. This figure also shows a personal computer (to be abbreviated as PC hereinafter)  11  that constitutes the trouble diagnosing device. The PC  11  is connected to the ECU  13  mounted on the vehicle and serving as an electronic control device, via a VCI (vehicle communication interface)  12  serving as an interface equipment and constituting the trouble diagnosing device. The ECU  13  includes an ECU for engine control, an ECU for air suspension, etc. The PC  11  and VC  112  are connected to each other via a multiple communication line  14 , and the VCI  12  and ECU  13  are connected to each other via a multiple communication line  15 . An end of the multiple communication line  15  is coupled to a diagnosis connector  13   d  of the ECU  13 . 
   The VCI  12  has a function of converting a communication specification used for the ECU  13  into a communication specification used for the PC  11 . The VCI  12  has a built-in microprocessor and has a memory  12   m  inside. 
   As described above, the trouble diagnosing device itself is pre-equipped with the interface equipment serving as an interface with the electronic control unit mounted on the vehicle. Thus, it is not necessary to particularly prepare a separate interface equipment. Therefore, the operation for matching the specifications with each other can be omitted and therefore the increase in production cost can be suppressed. 
   The ECU  13  has a diagnostic function. The diagnostic function means a self-diagnostic function. That is, the ECU  13  monitors input signals from various types of sensors, an actuator and switch, and when some abnormality occurs in anyone of the input signals, the ECU  3  stores the contents of the abnormality (diagnosis code) or the data at the time the abnormality occurred in the memory  13   m  as maintenance and repair data. 
   A predetermined area of the memory  13   m  further includes a current trouble information region  13   a  for storing current diagnosis codes, as shown in  FIG. 3A  and a past trouble information region  13   b  for storing past diagnosis codes, as shown in  FIG. 3B . In each of the current trouble information region  13   a  and the past trouble information region  13   b , for example, eight diagnosis codes can be stored at the maximum. When a starter switch (not shown) is turned on to start the engine, diagnosis codes generated are stored one after another into the current trouble information region  13   a  as current diagnosis codes in real time. When the starter switch (not shown) is turned off, the diagnosis codes stored in the current trouble information region  13   a  are transferred to the past trouble information region  13   b  of the memory  13   m , where the transferred codes are stored as past diagnosis code. After that, the current trouble information region  13   a  is cleared to zero. 
   As described above, the current trouble information region  13   a  is capable of storing eight current diagnosis codes at the maximum. For example, in the case where three current diagnosis codes are already stored in the current trouble information region  13   a , and additional diagnosis codes that are the same as any of these three already stored codes are generated, the three already stored diagnosis codes are maintained as they are. 
   In the case where eight current diagnosis codes are already stored in the current trouble information region  13   a , and a new current diagnosis code is generated, the oldest one of the already stored eight current diagnosis codes is deleted, and then the new current diagnosis code is stored in the current trouble information region  13   a.    
   Next, the structure of the PC  11  will now be described with reference to  FIG. 2 .  FIG. 2  shows a CPU (central processing unit)  21 . To the CPU  21 , a ROM (read-only memory)  22 , a RAM (random access memory)  23 , a key entry portion  24 , a touch-panel type display  25  having a rectangular display screen, an HDD (hard disk device)  26 , a communication I/F  27  and a printer I/F  28  are connected via a system bus  21   a.    
   The HDD  26  stores a trouble diagnostic program for executing the diagnostic functions. 
   The trouble diagnostic program includes the following programs: 
   (1) A main program as illustrated in  FIG. 4 ; and 
   (2) A program for displaying an image corresponding to a touch button displayed on the display  25  when an operator touches the button, and a program for executing a process designated by the button. 
   The details of these programs are as follows. For example, one of these corresponds to simultaneous display unit for displaying current diagnosis codes, past diagnosis codes, and a total number of each type of codes simultaneously on the display screen  31 . These data are displayed as a command for reading the current diagnosis codes and past diagnosis codes stored in the current trouble information region  13   a  and past trouble information region  13   b , respectively, a command for reading the total number of the current diagnosis codes and past diagnosis codes, etc., are output to the ECU  13  with the touch of a “self-diagnosis” button of the function menu, which will be described later. Another program corresponds to a trouble information erasing unit for instructing the ECU  13  to erase certain diagnosis codes of at least one type of the current diagnosis codes and past diagnosis codes stored in the current trouble information region  13   a  and past trouble information region  13   b , respectively, with the touch of an “eraser” button  43 . Still another program corresponds to a printing unit for printing a presently displayed image by transmitting the data corresponding to an image presently shown on the display screen  31  to a printer (not shown) via the printer I/F  28 . Still another program corresponds to a dialog-type trouble diagnosing unit for performing a dialog-type troubleshooting with the touch of a “code-by-code troubleshooting” button  42 . 
   It should be noted here that the RAM  23  has various work areas. 
   Next, the operation will now be described. The members are connected to each other as shown in  FIG. 1 . Then, the PC  11  is turned on to start up the trouble diagnosing program, and then the starter switch (not shown) of the truck is turned on, the trouble diagnosis illustrated by the flowchart shown in  FIG. 4  is started. 
   First, a startup image as shown in  FIG. 5  is displayed as the main menu on the display  25  (Step S 1 ). Next, when the “trouble diagnosis” button is selected, then a system selection image is displayed on the display  25 , in which one of the three systems, namely, engine, chassis and body can be selected (Step S 2 ). Next, when the chassis is selected from this image and then the air suspension is selected, the function selection image is displayed (Step S 3 ). 
   This function selection image presents buttons for the “self-diagnosis”, . . . , “calibration”, . . . . 
   When the “self-diagnosis” is selected from this image, what is shown in  FIG. 6  as a display screen  31  is displayed on the display  25 . In other words, when the “self diagnosis” button on the function display image is manipulated, the simultaneous display unit of the PC  11  transmits the command for reading the current diagnosis codes and past diagnosis codes stored in the current trouble information region  13   a  and past trouble information region  13   b , respectively, via the VCI  12  to the ECU  13 . The ECU  13 , when receiving this command, reads out the current diagnosis codes and past diagnosis codes stored in the current trouble information region  13   a  and past trouble information region  13   b , respectively, and transmit them to the PC  11 . The PC  11 , when receiving these codes, counts the total number of the current diagnosis codes and past diagnosis codes transmitted. 
   The display screen  31  illustrated in  FIG. 6  shows an example where three current diagnosis codes and one past diagnosis code are displayed. 
   On the left-hand side of the display screen  31 , a current trouble information display section  32  which is capable of five displaying current diagnosis codes at the maximum is provided, whereas a past trouble information display section  33  which is capable of five displaying past diagnosis codes at the maximum is provided. 
   More specifically, the current trouble information display section  32  is provided with five independent cells  32   a  to  32   e  in which trouble information are indicated, and similarly, the past trouble information display section  33  is provided with five independent cells  33   a  to  33   e . A width a of each of the cells  32   a  to  32   e  and cells  33   a  to  33   e  is about 0.39 inch (=1 cm) to 0.79 inch (=2 cm) when the display screen has a size of 12.1 inches. 
   As described above, when the display screen has a size of 12.1 inches (the length of a diagonal line of the screen image is about 31 cm), each of the cells  32   a  to  32   e  is displayed to have such a large width of about 0.39 inch (=1 cm) to 0.79 inch (=2 cm). With this size, if each cell of the trouble diagnosing device is manipulated by an operator in a maintenance and repair shop with work gloves on, the possibility of the operating error can be significantly reduced. 
   In the case where the display screen  31  has a size of 15 inches, it is preferable that the width of each of the cells  32   a  to  32   e  should be set to about 0.49 inch (=1.24 cm) to 0.98 inch (=2.48 cm). 
   In the case where the display screen  31  has a size of 17 inches, it is preferable that the width of each of the cells  32   a  to  32   e  should be set to about 0.56 inch (=1.41 cm) to 1.11 inches (=2.82 cm). Thus, the width of each cell should preferably be set to about 1/30 to 1/15 of the length of a diagonal line of the screen image. 
   DCT indicated at the top section of the current trouble information display section  32  is the abbreviation of diagnosis trouble code, which means current diagnosis node. 
   The contents shown in  FIG. 6  as the display screen  31  show an example in which the current trouble information display section  32  shows “11” as a current diagnosis code, “common rail pressure sensor” as the broken down part indicated by the code, “18” as another current diagnosis code, “INOMAT system” as the broken down part indicated by the code, “25” as still another current diagnosis code, “vehicle speed sensor” as the broken down part indicated by the code. Further, the past trouble information display section  33  shows “32”as a past diagnosis code, and “boost sensor” as the broken down part indicated by the code. 
   As described above, when the “self diagnosis” button of the function display image is manipulated, current diagnosis codes and past diagnosis codes are indicated in the current trouble information display section  32  and the past trouble information display section  33 , respectively, at the same time on the display screen  31  so that they can be compared and contrasted with each other. In this manner, troubles that occurred in the past and those occurred this time can be easily compared with each other. Thus, it is possible to recognize the past troubles and current troubles at a glance without switching the images during the repair. Therefore, the ease of repair can be improved. 
   Further, the current trouble information display section  32  includes in its lower portion a total trouble count indicating section  34   a  that indicates the total number of current diagnosis codes. Similarly, the past trouble information display section  33  includes in its lower portion a total trouble count indicating section  34   b  that indicates the total number of past diagnosis codes. The total number of current diagnosis codes indicated in the total trouble count indicating section  34   a  and the total number of past diagnosis codes indicated in the total trouble count indicating section  34   b  can be obtained by counting, on the PC  11  side, the number of current diagnosis codes and the number of past diagnosis codes, respectively, which have been transmitted from the ECU  13 . 
   According to the embodiment, the total number of each group of the present and past diagnosis codes is indicated, and therefore it is possible to know whether there are more data present that cannot be displayed in the current trouble information display section  32  and past trouble information display section  33 . Thus, it is very hard to miss even those diagnosis codes that are not displayed in the image screen. 
   Further, the total number of each of the current and past diagnosis codes is displayed, and therefore it is possible to know how serious is a trouble at a glance, and to know the frequency of troubles of the ECU  13 . 
   For example, in the example shown in the figure, three current diagnosis codes are indicated in the current trouble information display section  32 , and the count indicated in the total trouble count indicating section  34   a  is “3”. Therefore, in this case, it is possible to understand that all of the current diagnosis codes are presently indicated in the current trouble information display section  32 . 
   Suppose here the case where five current diagnosis codes are indicated in the current trouble information display section  32  and the count indicated in the total trouble count indicating section  34   a  is “8”. In this case, three current diagnosis codes remain not displayed. In order to display these three remaining current diagnosis codes on the current trouble information display section  32 , the data can be scrolled on the screen by appropriately manipulating the cursor buttons  35  and  36  provided on the right-hand side of the current trouble information display section  32 . 
   Cursor buttons  37  and  38  designed to scroll displayed data are displayed on the right-hand side of the past trouble information display section  33 . 
   Thus, with the total number of each group of the current and past diagnosis codes displayed, it is possible to know how serious is a trouble at a glance, and to know the frequency of troubles of the ECU  13  as a whole. 
   Further, the section of the menu bar provided in the lowermost section of the display screen  31  displays the display button  41  for printing the contents presently shown on the display screen  31 , the “code-by-code troubleshooting” button  42  for performing a dialog-type troubleshooting, and the “eraser” button  43  for erasing certain diagnosis codes of at least one group of the current diagnosis codes and past diagnosis codes stored in the current trouble information display section  32  and past trouble information display section  33 , respectively. 
   For example, when the printing button  41  is manipulated by touching it, the contents of the current display screen  31  are printed and output from a printer (not shown) connected the printer I/F  28 . 
   Thus, the current diagnosis codes and past diagnosis codes are printed at the same time on the same sheet, the record of maintenance and repair can be easily and accurately formed. Further, for printing, it suffices only if the printing button  41  is touched, and thus the printing order can be easily made. Furthermore, by having the current trouble data and past trouble data on a print, the data can be accurately passed on to another mechanic who next takes case of the vehicle, thereby making it possible to improve the efficiency of the maintenance and repair. 
   Moreover, when one of the cells  32   a  to  32   e  in which current diagnosis codes or past diagnosis codes are displayed is selected by touching it, and then the “code-by-code troubleshooting” button  42  is touched, the dialog-type trouble diagnosis corresponding to the selected diagnosis code is started. In other words, under what conditions the selected diagnosis code occurred is indicated on the displayed image  31 , and the maintenance and repair data stored in the memory  13   m  of the ECU  13  are displayed. Thus, with these displayed data, the inspection procedure can be carried out in a dialog manner. 
   As described above, an operator can easily take care of the trouble without referring to the maintenance and repair guidebook. 
   On the other hand, when at least one of the current trouble information display section  32  and past trouble information display section  33  is selected by touching it, and then the “eraser” button  43  is touched, the data of the selected one of the current diagnosis codes and past diagnosis codes are erased from the memory  13   m.    
   In this manner, for example, when the cause for a trouble is investigated and the troubled part is repaired in a maintenance and repair shop, the current diagnosis codes and past diagnosis codes can then be erased to start a new self-diagnosis. 
   In case where a vehicle with a trouble is brought in a maintenance and repair shop, but the trouble is not detected as current trouble information, such a conduct that easily causes a trouble as shaking a part to be inspected is performed. If trouble information corresponding to the inspected part is detected as current trouble information after this conduct, it can be judged that the inspected part is broken. Thus, it is possible to carry out the investigation of the cause for a trouble. 
   It should be noted here that it is alternatively possible to print out those current diagnosis codes and past diagnosis codes that are not displayed in the display screen  31  when the printing button  41  is touched, as well if there are any. 
   In the above-described embodiment, the total number of each group of the current diagnosis codes and past diagnosis codes transmitted from the ECU  13  is counted on the PC  11  side; however it is alternatively possible to count the total number on the ECU  13  side, and transmit it to the PC  11 . 
   The renewal manner of the current diagnosis codes stored in the current trouble information region  13   a  of the memory  13   m  and the past diagnosis codes stored in the past trouble information region  13   b , which was described with reference to  FIGS. 3A and 3B  is not limited to that of this embodiment, but it can be modified into various versions. 
   It should be noted that in the above-described embodiment, the programs that correspond to various units are stored in the HDD  26 ; however the present invention is not limited to this, but it is alternatively possible to store these programs in an external storage means such as a CD-ROM or FD, and download them to the HDD  26  of the PC  11  as needed. 
   Further, in the above-described embodiment, a touch panel-type display is used; however in the case of a PC that does not equipped with a touch panel-type display, each operation can be assigned with use of a mouse. 
   Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.

Technology Category: 3