JP2005069909A - Speed meter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a speed meter capable of displaying maximum speed V<SB>MAX</SB>in each acceleration process in real time. <P>SOLUTION: The speed meter comprises the present speed V<SB>n</SB>calculation means 3 for calculating present speed Vn at every pulse generation of the pulse generator 1, the memory means 4 for revision and storage of the V<SB>n</SB>, the present speed display and control means 5 for revision and display the V<SB>n</SB>on the display 6, the maximum speed detection means 8 for revision and displaying the larger value as the V<SB>MAX</SB>by comparing every calculated value V<SB>n</SB>with the stored value; the minimum speed detection means 9 for revision and storage of the smaller value as the minimum speed V<SB>MIN</SB>by comparing the every calculation of the V<SB>n</SB>with the storage value; the deceleration determination means 10 for initializing the storage value of means 9 when determined that the deceleration is confirmed based on the time series of the V<SB>n</SB>; the maximum speed display and control means 11 for displaying the V<SB>MAX</SB>for 4 sec on the display 6 when the deceleration is confirmed; the initializing means 12 for initializing the storage value of the means 8 for every revision of the storage of the means 9 after initializing the means 9; and the acceleration determination means 13 for determining the right or wrong of the acceleration confirmation B based on the time series of the V<SB>n</SB>when confirming deceleration time, and resetting the means 10 when the acceleration confirmation B is confirmed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a speedometer suitable for mounting on a racing car or the like, and more particularly to a speedometer capable of displaying in real time a maximum speed at a straight end and a minimum speed during cornering.

  Some digital display type speedometers installed in racing cars can not only display the current speed digitally in real time, but also hold the maximum speed during the entire driving period and display the maximum speed on the display after the driving ends. It has been known.

  In a racing car, the brakes are braked with the foot brake just before entering the corner from the straight (straight section), and the accelerator is opened to accelerate and compete for the lap time just before exiting the corner. The maximum speed (maximum speed value) and the minimum speed (minimum speed value) in each deceleration zone will be improved so that the driving skill will be improved, so the maximum speed value in the acceleration zone and the minimum speed value in the deceleration zone Need to know in real time as Merckmar.

  Accordingly, a first object of the present invention is to provide a speedometer capable of displaying or instructing in real time the maximum speed value (speed maximum value) in each acceleration process after the second time.

  A second object of the present invention is to provide a speedometer capable of displaying or instructing in real time the minimum speed value (minimum speed value) in each deceleration process.

  In order to solve the first problem, the present invention provides a pulse generation means for generating a pulse at a time period corresponding to a rotational speed, and a speed value calculation for calculating a speed value based on the pulse width for each incoming pulse. A speedometer having means, a current speed storage means for updating and holding the speed value as a current speed value every time the speed value is calculated, and a visual indicator for updating and displaying the speed value every time the speed value is calculated Each time the speed value is calculated, the speed value is compared with the holding value, and when the speed value is equal to or higher than the holding value, the maximum speed detecting means for updating and holding the speed value as the maximum speed value, and deceleration information relating to the rotation speed And a predetermined deceleration determination criterion to determine whether or not the deceleration confirmation is appropriate, and when the deceleration determination means determines that the deceleration is confirmed, the maximum speed value held by the maximum speed detection means is Display over time or A maximum speed display control means for Shimesuru control, after the deceleration determining unit determines that confirmation deceleration, comprising a maximum speed initializing means for initializing the holding value of the maximum speed detecting means. Here, the visual indicator may be a digital or analog type indicator or a meter having a pointer indicating the speed display value of the scale plate. In addition to the time series of speed values, for example, a blinking signal of a stop lamp or an output signal of an acceleration sensor can be used as deceleration information related to the rotational speed in the case of an in-vehicle speedometer.

  First, in the initial acceleration process that is initially started from the stop state, the stored value of the current speed storage means continues to update the maximum speed value every time the speed value is calculated, and the current speed in the acceleration process is updated or displayed by a visual indicator. Is. Once entering the deceleration process, once the current speed storage means continues to hold the maximum speed value, which is the maximum value of the speed in the initial acceleration process, the transition of the deceleration information related to the rotational speed meets the predetermined deceleration criterion. Since the deceleration determination means determines that the deceleration has been confirmed, the maximum speed display control means displays or indicates the maximum speed value, which is the maximum value of the speed, in the middle of the deceleration process over the first time period. Therefore, the maximum speed value (speed maximum value) in the initial acceleration process can be known in real time. When the transition of the deceleration information does not match the predetermined deceleration determination criterion, the maximum speed value is not displayed or instructed by the visual recognition device, and the current speed value is continuously updated or displayed.

  As a criterion for deceleration determination, for example, in the case of an in-vehicle speedometer, it can be set in advance with reference to the deceleration continuation time and the degree of deceleration when footbrake braking over a certain period of time occurs. , Instantaneous deceleration when changing gears, and display or instruction of confusing maximum speed values during temporary deceleration due to intermittent footbrake braking are not required, and maximum speed values during footbrake braking based on deceleration intentions Is displayed instructively, which contributes to the improvement of driving skill.

  Then, after the deceleration determining means determines that the deceleration is confirmed, it has a maximum speed initializing means for initializing the hold value of the maximum speed detecting means, so the maximum speed in the second acceleration process after the deceleration process is determined. The maximum speed value in each acceleration process can be displayed or instructed.

  Here, the timing for initializing the holding value of the maximum speed detecting means is after the deceleration determining means determines that the deceleration is confirmed, but when initializing immediately after the determination, the deceleration before entering the second acceleration process During the process, it is not known when the minimum speed value that is the minimum value will arrive, so if the stored value of the maximum speed detecting means is initialized in preparation for the second acceleration process, the stored value of the maximum speed detecting means The maximum value in the deceleration process after the initialization is held, and when the maximum speed value in the second acceleration process is lower than this maximum value, the second acceleration process in the second deceleration process Instead of the maximum speed value in the process, the maximum value immediately after the initialization in the first deceleration process can be displayed or indicated. Probabilistic false detection occurs.

  In addition, as the maximum speed initialization means, it can be a timed initialization means that initializes after a certain time has elapsed from the time when it is determined to confirm deceleration, but the initialization time is the minimum value point in the initial deceleration process. The maximum value in the second acceleration process can be captured only when it is between and the maximum value point in the second acceleration process, and otherwise it can be a false detection.

  Therefore, as the maximum speed initialization means, after the deceleration determination means determines that the deceleration is confirmed, the acceleration information related to the rotational speed is compared with a predetermined acceleration determination criterion to determine whether the acceleration confirmation is appropriate. Acceleration determination means for initializing the held value of the maximum speed detection means. The detection of the maximum speed value after the second time is more reliable than in the case of the above two examples. However, since acceleration is slower than deceleration, in the unlikely event that the maximum point of time arrives at the same time as acceleration confirmation, a false detection may occur. In addition, when the acceleration information related to the rotation speed for the acceleration determination means is obtained from the speed value, the acceleration determination itself cannot be performed, and therefore the acceleration information is limited to the output of the acceleration sensor separately.

  Therefore, it is necessary to capture the time point of the speed minimum value without using the acceleration determination means. Therefore, every time the speed value is calculated, the speed value is compared with a holding value, and when the speed value is equal to or less than the holding value, a minimum speed detecting means for updating and holding the speed value as the minimum speed value is provided, and a deceleration determining means Initializes the hold value of the minimum speed detection means when it is determined that the deceleration is confirmed, and the maximum speed initialization means initializes the hold value of the maximum speed detection means when the update of the hold value of the minimum speed detection means stops. . When the minimum speed value is passed, the updating operation of the minimum speed detecting means stops, and the retained value of the maximum speed detecting means is initialized by the maximum speed initializing means at the beginning of the second acceleration process. For this reason, the maximum speed after the second time can be detected. However, in the case of an in-vehicle speedometer, although the acceleration is slow, the update operation of the minimum speed detection means stops even with slight acceleration, and even if it is not intentional acceleration, the retained value of the maximum speed detection means is the initial value. Therefore, initialization is executed when instantaneous acceleration is lost in the deceleration process. In this way, when the minimum speed value, which is the minimum value in the first deceleration process, appears as the current speed value, it is necessary to reset the retained value of the maximum speed detection means to the current speed value. It is difficult to reliably capture when the minimum speed value appears.

  As a result of trial and error, the inventor compares the speed value with the hold value for each calculation of the speed value, and updates and holds the speed value as the minimum speed value when the speed value is equal to or less than the hold value. A detection means is provided, and when the deceleration determination means confirms the deceleration, the value held by the minimum speed detection means is initialized, the standby value is detected so that the minimum speed value that is the minimum value in the deceleration process can be detected, and the minimum speed detection means is initialized. A maximum speed initializing means for initializing the holding value of the maximum speed detecting means every time the holding value of the minimum speed detecting means is updated later is provided.

  As long as deceleration continues, the holding value of the minimum speed detecting means continues to be updated as the minimum speed value. Therefore, every time this updating operation occurs, that is, every time deceleration continues, the holding value of the maximum speed detecting means is initialized and immediately. Since the operation updated to the current speed value is repeated, at the end of the deceleration process, the value held by the maximum speed detection means also becomes the minimum speed value (minimum value) in the deceleration process. Therefore, regardless of what time the minimum speed value that is the minimum value is present, the value held by the maximum speed detecting means can be set to the minimum speed value that is the minimum value before entering the second acceleration process. The maximum speed value in the acceleration process can be reliably captured. The same applies to the third and subsequent times.

  The maximum speed display control means controls to display or indicate a mark indicating the maximum speed when the maximum speed value is displayed or instructed over the first time period with the viewer. In addition, a notification sound may be generated at that time, and the maximum speed value may be output as a sound.

  By making the deceleration information related to the rotational speed into a time series of speed values obtained from the speed value calculating means, a speedometer can be configured with only a single signal system from the pulse generating means without using an acceleration sensor or the like. It is possible to save the trouble of installation work.

  Here, the higher the speed, the shorter the pulse generation period and the higher the speed of the pulse, so the interval between the calculation of the velocity values becomes small, and the interval is not always constant. Deceleration criteria are not leveled.

  Therefore, there is a speed value storage means that updates and holds a speed value that is a predetermined time earlier than the current speed value held by the current speed storage means as the previous speed value. Deceleration value determination means that calculates a decrement value from the previous speed value to the current speed value, compares the decrement value with the deceleration reference value or not, and determines that the deceleration is confirmed when the decrement value is greater than the deceleration reference value Have Since the decrement value can be calculated at every predetermined time step, the absolute decrement value can always be obtained even in each deceleration process, and the deceleration judgment standard in each deceleration process is leveled.

  However, in the case of in-vehicle speedometers, for example, with the deceleration degree determination means alone, it is determined that deceleration is confirmed even during momentary or intermittent footbrake braking, so even if the brake is momentarily applied during the acceleration process, the maximum speed There is an inconvenience that the value is displayed. In order to eliminate such an inconvenience, the present invention adopts a double determination method.

  That is, as a specific configuration of the deceleration determination means, a decrement value from the previous speed value to the current speed value is calculated at predetermined time intervals, and whether the decrement value is equal to or greater than the deceleration reference value is compared in magnitude. Deceleration degree determination means that determines that there is deceleration when the deceleration is above the reference value, and counts the number of times that the deceleration occurs continuously in predetermined time increments. And a number of times determination means. Since such a double determination means is used, for example, in the case of an in-vehicle speedometer, when coasting or engine braking, the deceleration degree determination means determines that the decrement value does not reach the deceleration reference value, Even in the case of foot brake braking, in the case of instantaneous or intermittent brake braking, the number determination means does not determine deceleration, so that it is determined that deceleration occurs when foot brake braking is performed for a certain period of time.

  In order to solve the second problem, in addition to the above-described configuration, the present invention compares the acceleration information related to the rotational speed with a predetermined acceleration criterion after the deceleration determination unit determines that the deceleration is confirmed. Acceleration determining means for determining whether or not it is correct, and minimum speed display for controlling to display or instruct the minimum speed value held by the minimum speed detecting means within the second time period when the acceleration determining means determines acceleration confirmation. And a control means. With this configuration, when the acceleration determination unit determines that the acceleration is confirmed, the minimum speed value in the deceleration process that is immediately before the acceleration process can be displayed or instructed in real time. The minimum speed display control means can be configured to display or indicate a sign indicating the minimum speed when the minimum speed value is displayed or instructed over the second time period with a visual indicator. In addition, a notification sound may be generated at that time, and the minimum speed value may be output as a sound.

  The acceleration information related to the rotational speed is also a time series of speed values obtained from the speed value calculating means, so that a speedometer can be configured with only one signal system from the pulse generating means without using an acceleration sensor or the like. It is possible to save troubles such as mounting work.

  In the case of an in-vehicle speedometer, the acceleration process opens the accelerator to increase the driving force, so the acceleration is relatively slow compared to the degree of deceleration in the case of brake braking, and the momentary inertia when changing gears Therefore, a special device is required for the acceleration determination means.

  Therefore, as an acceleration determination means, an incremental value from the minimum speed value to the current speed value is calculated, and a comparison is made as to whether or not the incremental value is greater than or equal to the acceleration reference value. Acceleration / deceleration degree determination means for determining acceleration confirmation is provided. In other words, the acceleration determination means determines acceleration when the acceleration reference value is exceeded from the minimum speed value (minimum value) (threshold value) even if the acceleration is relatively slow, so that the minimum speed value is accurately captured. Can be displayed in real time.

The speedometer according to the present invention is not limited to an on-vehicle traveling speedometer, but can also be used as a “rotometer” for measuring the rotational speed of an engine or the like. It can be used for a number or speed inspection device and can display not only a straight speed but also an angular speed. In the present application, not only a speed value that is a first derivative but also an acceleration value that is a second derivative is "speed". In addition, the present invention is not limited to the speedometer provided with a visual recognition device such as a display device, but can also be used as a maximum speed detection device or an extreme speed detection device in which the visual recognition device is not provided. That is, as such a speedometer, a pulse generating means for generating a pulse with a time period corresponding to the rotational speed, a speed value calculating means for calculating a speed value based on the pulse width for each incoming pulse, and a speed Current speed storage means that updates and holds the speed value as the current speed value every time the value is calculated, and the speed value when the speed value is greater than or equal to the held value when the speed value is compared with the held value each time the speed value is calculated The maximum speed detection means that updates and holds the speed value as the maximum speed value, and the speed value is compared with the hold value for each speed value calculation, and when the speed value is less than the hold value, the speed value is updated and held as the minimum speed value. A minimum speed detecting means that outputs the maximum speed value held by the maximum speed detecting means when the deceleration confirmation information relating to the rotational speed is generated, and initializes the held value of the minimum speed detecting means, and then the minimum speed detecting means Holding And a control means for outputting the minimum speed value held by the minimum speed detection means when the acceleration confirmation information relating to the rotational speed is generated after the hold value of the maximum speed detection means is initialized at every update. .

  In short, the maximum speed value held by the maximum speed detection means is output when the deceleration determination means determines that the deceleration is confirmed in the deceleration process, and the minimum speed value in the deceleration process is initialized by initializing the value held by the minimum speed detection means. After that, the value held in the maximum speed detection means is initialized every time the value held in the minimum speed detection means is updated, and the minimum speed value is set to the maximum speed detection means at the time of the minimum speed value in the deceleration process. After reaching the hold value, when the acceleration determination means determines acceleration confirmation, the minimum speed value held by the minimum speed detection means is output, so the maximum speed value in each acceleration process and each deceleration process are output. The minimum speed value can be output alternately in real time.

  As described above, according to the speedometer of the present invention, the maximum speed value (speed maximum value) in each acceleration process after the second time can be displayed in real time. Further, the minimum speed value (minimum speed value) in each deceleration process can be displayed in real time.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a functional block diagram showing an in-vehicle speedometer according to an embodiment of the present invention, and FIGS. 2 to 5 are flowcharts showing a processing procedure of a microcomputer in the in-vehicle speedometer.

The in-vehicle speedometer of this example is mainly composed of a microcomputer (MPU), and as shown in FIG. 1, an in-vehicle vehicle speed pulse generator 1 that generates a vehicle speed pulse at a time period corresponding to the vehicle speed, and the vehicle speed pulse. a waveform shaper 2 for shaping the waveform into a rectangular pulse, a speed calculating unit 3 for calculating a current velocity value V _n on the basis of the pulse width for each incoming rectangular pulse, the current updating holds the current speed value V _n having a speed storage unit 4, the current speed display control unit 5 for the current update display the velocity value V _n, and a drive circuit 7 to display the signal of the current speed value V _n on the display 6 by the power amplifier.

The speedometer, the current speed value V _n when the current speed value V _n for each calculated relative retention values and the magnitude is the current speed value V _n of more than the holding value of the velocity value as the maximum speed value V _MAX From the maximum speed detecting means 8, the current speed value V _n when holding value and compares the speed value V _n is the current speed value V _n current below the holding value for each calculation of the velocity values to update preserving the minimum speed detector 9 for updating retained as velocity value V _MIN, to determine the propriety of the confirmation time decelerate the series changes against the predetermined deceleration criterion current speed value V _n, when the delivery of the deceleration confirmation information a The deceleration determination means 10 for initializing the hold value of the minimum speed detection means 9 and the maximum speed value V _MAX held by the maximum speed detection means 8 when the deceleration determination means 10 sends the deceleration confirmation information A to the display 6 Maximum for displaying the first time period (4 seconds) The speed display control means 11 and the maximum speed initialization means 12 for initializing the holding value of the maximum speed detecting means 8 every time the holding value of the minimum speed detecting means 9 is gradually updated after the initialization of the minimum speed detecting means 9. When the deceleration determination means 10 sends the deceleration confirmation information A, the time series transition of the speed value is checked against a predetermined acceleration judgment standard to determine whether or not the acceleration confirmation is successful. And an acceleration determination means 13 for resetting the determination means 10.

Speedometer, previous to update preserving the speed value before 0.1 seconds from the current speed value V _n of the current speed storing means 4 is held by the 0.1 second clock means 15 as a previous velocity value V _n-1 It has a speed value storage means 14, and the deceleration determination means 10 calculates a decrement value ΔV from the previous speed value V _n−1 to the current speed value V _{n in} increments of 0.1 seconds and calculates the decrement value ΔV. A deceleration degree determining means (not shown) for comparing whether or not the deceleration is greater than or equal to a deceleration reference value (0.5 km / h) and determining that there is deceleration when the deceleration is greater than or equal to the deceleration reference value (0.5 km / h) And a deceleration number determination means (not shown) for determining the deceleration confirmation A when the number of times of occurrence of deceleration is counted continuously every 0.1 second and the reference number is 3. .

The speedometer also displays the minimum speed value V _MIN held by the minimum speed detection means 9 when the acceleration determination means 13 sends the acceleration confirmation information B on the display unit 6 for the second time period (4 seconds). Means 16. The acceleration determination means 13 calculates an increment value δV from the minimum speed value V _MIN to the current speed value V _n and compares whether the increment value δV is greater than or equal to the acceleration reference value (6 km / h). When the increment value δV is equal to or greater than the acceleration reference value (6 km / h), it is an acceleration / deceleration degree determination means for determining acceleration confirmation.

Then, the speedometer includes a time reset unit 17 that resets the deceleration determination unit 10 when a certain time (30 seconds) elapses after the deceleration determination unit 10 sends the deceleration confirmation information A. Note that a sounding device 18 for sounding an alarm when the maximum speed value V _MAX or the minimum speed value V _MIN is displayed on the display 6 is provided.

The display 6 is composed of a 7-digit LED with 3 digits, and a speed value display section for displaying the current speed value V _n , maximum speed value V _MAX or minimum speed value V _MIN , and 7 segments on the right side of the least significant digit It comprises an LED, and has an extreme value identification unit for displaying a sign “H” indicating the maximum speed value or a sign “L” indicating the minimum speed value.

  Next, the operation procedure of the present embodiment will be described with reference to FIGS.

FIG. 2 shows various initial settings and a main routine. First, the operation procedure starts when the vehicle power is turned on (ignition signal), the initial setting of the 0.1 second timer interrupt routine, the initial setting of the pulse edge detection interrupt routine, the initial setting of the display interrupt routine, each flag (deceleration confirmation flag) , Acceleration confirmation flag, start flag), and interrupt permission of each interrupt routine, the main routine performs key switch (KEY SW) input processing in step M1 and functions (modes) based on it in step M2. The change process is executed cyclically. This key switch (KEY SW) is a pushbutton switch for mode switching (not shown) provided in the speedometer. In the normal mode in which the pushbutton switch is off, the maximum speed value V _MAX and the minimum speed value V _{MIN are used.} When the push button switch is in the ON state, the maximum speed value V _MAX and the minimum speed value V _MIN are not displayed, but only the current speed value V _n is displayed. The operation procedure in the normal mode will be described below.

Figure 3 is a flow diagram of the pulse edge detection interrupt routine starts every incoming rectangular pulse in step S1, detects each pulse edge and converts the pulse width to the current speed value V _n at the step S2. The processing in step S1 and step S2 corresponds to the function of the speed value calculation means 3. As a function of the current speed storing unit 4 temporarily stores the current speed value V _n at step S3. Since the temporary storage time is a period until the next current speed value is generated, the temporary storage time is shortened as the vehicle speed increases.

In step S4, compared magnitude current speed value _{V n} of the holding value (minimum speed value _{V MIN),} in step S5, the current speed value _{V n} is held value (the minimum speed value _{V MIN)} or less when the current speed value V _n is updated and held as a new minimum speed value _VMIN . Steps S4 and S5 correspond to the function of the minimum speed detection means 9. When the first rectangular pulse arrives, the minimum speed value V _MIN is temporarily set to 400 km / h, which is an unrealistic value (unmeasured value) by the initial setting of the pulse edge detection interrupt routine of FIG. Yes. In step S6, the maximum speed value V _MAX is initialized to zero as a function of the maximum speed initialization means.

Conversely, when the current speed value _{V n} of the above retention value (minimum speed value _{V MIN)} in step S4, the current speed value _{V n} and compares with retention values (maximum speed value _{V MAX)} at step S7, step the current speed value _{V n} at S8, update holds the holding value (maximum speed value _{V MAX)} or the current speed value _{V n} when as a new maximum speed value _{V MAX.} The processing in step S7 and step S8 corresponds to the function of the maximum speed detecting means 8.

When the current speed value Vn is _equal to or less than the hold value (minimum speed value _VMIN ) in step S7, it is determined in step S9 whether or not a deceleration confirmation flag is set. This setting of the deceleration confirmation flag corresponds to the transmission of the deceleration confirmation information A from the deceleration determination means 10, but when the deceleration confirmation flag is not set, the pulse edge detection interrupt routine is terminated and the next pulse is generated. When the deceleration confirmation flag is set, in step S10, the acceleration determination means 13 obtains the value obtained by adding the acceleration reference value (6 km / h) to the minimum speed value V _MIN and the current speed value V _n . and compares, when the current smaller for the speed value V _n waits for occurrence of the next pulse to exit the pulse edge detection interrupt routine, when the current is larger velocity value V _n, the acceleration determination flag in step S11 Is set, and the deceleration confirmation flag is cleared in step S12. The processing from step S10 to step S12 corresponds to the function of the acceleration determination means 13, and the setting of the acceleration confirmation flag corresponds to acceleration confirmation B.

In step S13 as a function of the minimum speed display control means 16, the minimum speed value _VMIN is set as the display data _VSC , and the pulse edge detection interrupt routine is terminated.

  Next, FIG. 4 is a flowchart of the 0.1 second timer interrupt routine. In step SP1, the 0.1 second clock means 15 is activated every time a 0.1 second clock is generated, and the deceleration confirmation flag is set in step SP2. It is determined whether or not it has been done.

When the deceleration decision flag is not set, compares the magnitude of the value and the current speed value V _n by subtracting the deceleration reference value from the previous velocity value V _n-1 to (0.5km / h) in step SP3, the current speed when the larger value V _n, and resets the count of the counter at step SP4. If the deceleration confirmation flag is set, the counter count is incremented by 1 in step SP5, and it is determined in step SP6 whether or not the counter count value is equal to 3. If equal, the deceleration confirmation flag is determined in step SP7. Set. In step SP8 as a function of the maximum speed display control unit 11, the display data _{V SC} maximum speed value _{V MAX.} In step SP9, the minimum speed value V _MIN is initialized to 400 km / h. The processing in steps SP3 to SP7 and step SP9 corresponds to the function of the deceleration determination means 10, the processing in step SP3 corresponds to the deceleration degree determination means, and the processing in SP4 to SP7 and step SP9 corresponds to the deceleration count determination means, respectively. doing. The setting of the deceleration confirmation flag corresponds to the transmission of the deceleration confirmation information A.

If the deceleration confirmation flag is set in step SP2, it is determined in step SP10 whether or not 30 seconds have elapsed. If it has elapsed, the deceleration confirmation flag is cleared in step SP11. The processing of steps SP10 and SP11 corresponds to the function of the time limit reset means 17. Then, when not passed 30 seconds, the processing completion of step SP11,4,9, and when the count value of the step SP6 is less than 3, the previous speed the current speed value _{V n} at the step SP12 as a function of the preceding speed storing means 14 The value is updated as V _n−1 , the 0.1 second timer interruption routine is terminated, and the next 0.1 second clock generation is awaited.

FIG. 5 is a flowchart of the display interrupt routine. The display interrupt routine is started at regular intervals, and it is determined whether or not the acceleration confirmation flag is set in step P1. If not, the deceleration confirmation flag is set in step P2. It is determined whether or not. When the deceleration decision flag is not set to display control on the display unit 6 the current speed value V _n through the driving circuit 7 in step P3. Such processing in steps P1 to P3 corresponds to the function of the current speed display control means 5.

When the deceleration confirmation flag is set in step P2, it is determined whether or not the start flag is set in step P4. If it is not set, the start flag is set in step P5 and the highest flag is already set in step P6. to display the display data _{V SC} that is the velocity value _{V MAX.} If the start flag is set in step P4, it is determined in step P7 whether or not the display time for continuing to display the maximum speed value V _MAX has elapsed for 4 seconds. If not, the display interrupt routine is terminated. And wait for the next interrupt time. If it has elapsed, the deceleration confirmation flag is cleared in step P9, the start flag is cleared in step P9, the display interrupt routine is terminated, and the next interrupt time is awaited.

In step P1, it is determined whether an acceleration confirmation flag is set. If it is set, it is determined in step P10 whether a start flag is set. When not set to set the start flag in step P11, and displays the display data V _SC that is already the lowest velocity value V _MIN in step P12. When the start flag is set in step P10, it is determined in step P13 whether or not the display time for continuing to display the minimum speed value _VMIN has elapsed for 4 seconds. If not, the display interrupt routine is terminated. And wait for the next interrupt time. If it has elapsed, the acceleration confirmation flag is cleared in step P14, the start flag is cleared in step P15, the display interrupt routine is terminated, and the next interrupt time is awaited.

  Next, the operation of this embodiment will be described based on one example of the vehicle speed transition shown in Tables 1 to 4. In the following description, the speed unit (km / h) is omitted.

  Table 1 shows the period from the initial acceleration process to the deceleration confirmation.

［初回目の最高速度値の表示］ 車輌電源がオンされてエンジンが始動した時点では、最低速度値Ｖ_ＭＩＮは実測不能値の４００．０に一瞬初期設定されるが、初動による表示限界（０．１）以下の極低速度により、表１に示す如く、時刻０．０秒では現在速度値Ｖ_ｎが０．０であると、最低速度検出手段９の保持する最低速度値_ＭＩＮは０．０に更新され（ステップＳ５）、また初期設定により最高速度値Ｖ_ＭＡＸ，前回速度値Ｖ_ｎ−１も０．０であり、減速確認情報Ａ（減速確定のセット）及び加速確認情報Ｂ（加速確定のセット）が未送出であるため、表示値も０．０であり、更に加速判定手段１３は閾値（最低速度値値_ＭＩＮ＋６）の演算を行わない。

[Display of First Maximum Speed Value] When the vehicle power is turned on and the engine is started, the minimum speed value V _MIN is initially set to 400.0, which is an unmeasurable value, but the display limit (0 the very low rate of .1) or less, as shown in Table 1, when the time 0.0 seconds current speed value _{V n} is 0.0, the minimum speed value _MIN to hold the minimum speed detector 9 0. It is updated to 0 (step S5), and the maximum speed value V _MAX and the previous speed value V _n-1 are also 0.0 by the initial setting, and deceleration confirmation information A (deceleration confirmation set) and acceleration confirmation information B (acceleration) Since the confirmed set) has not been sent, the display value is also 0.0, and the acceleration determination means 13 does not calculate the threshold value (minimum speed value _MIN + 6).

Thereafter, the vehicle gradually accelerates, and the maximum speed value V _MAX is gradually updated every time a rectangular pulse is generated, and the current speed value V _n is 98.0 at time 5.0 (when 0.1 second clock is generated). The maximum speed value V _MAX and the display value become 98.0, and the previous speed value V _n-1 is the current speed value V _n at time 4.9 seconds (when 0.1 second clock is generated). 95.0, and the further accelerated the vehicle, the time 9.9 current speed value _{V n} in (0.1 sec clock time generator) reaches 100.0, a display value becomes 100 maximum velocity value _{V MAX} The previous speed value V _n−1 is 98.0, which is the current speed value V _n at time 9.8 seconds (when a 0.1 second clock is generated). The rectangular pulse generated by the intermediate time t1 and time 9.9 seconds and the time 10 seconds (the time of 0.1 second clock generation), when the current speed value _{V n} reaches 100.5, also displays the maximum velocity value _{V MAX} The value is also 100.5.

From time 10 seconds to time 10.3 seconds, a sudden deceleration process is started by foot brake braking. Since time 10 seconds (at 0.1 second clock generation) the current speed value _{V n} falls 100.0, although the display value becomes 100.0, current maximum speed detecting means 98.0 is at time t1 continues to hold the velocity value _{V n} as the maximum speed value _{V MAX,} the time t2, t3, the current speed value _{V n} and the display value in t4 decreases progressively 99.5,99.0,98.5, time 10. 1 When in (at 0.1 second clock generation) the current speed value _{V n} becomes 98.0, since the previous velocity value _{V n-1} is 100.0, the deceleration degree deceleration reference value (0.5) It exceeds 2.0, and the number of times of deceleration is 1. Time t5, t6, remained current speed value _{V n} and the display value in t7 gradually 97.5,97.7,97.5 the current speed value at time 10.2 (at 0.1 second clock generation) V _{When n} becomes 97.0, the previous speed value V _n-1 is 98.0, so the degree of deceleration becomes 1.0 exceeding the deceleration reference value (0.5), and the number of times of deceleration becomes 2. Time t8, t9, remained current speed value _{V n} and the display value in t10 gradually 96.8,96.7,96.5 the current speed value at time 10.3 (at 0.1 second clock generation) V _{When n} becomes 96, since the previous speed value V _n-1 is 97.0, the deceleration degree becomes 1.0 exceeding the deceleration reference value (0.5), and the number of times of deceleration becomes 3, so that the deceleration determination means 10 sends the deceleration confirmation information A, and 100.5 is displayed on the display 6 as the maximum speed value V _MAX which is the maximum value at the time point t1, and a sign “H” indicating that it is the maximum speed is also displayed. . At the time of displaying the maximum speed value, the sound generator 18 sounds an alarm sound. Further, by sending the deceleration confirmation information A, the minimum speed value V _MIN is initialized to 400.0 (step SP9), and the acceleration determination means 13 is executed to execute acceleration determination (step S10). The calculation of the value _MIN + 6 is 406.0.

  Since the maximum speed value is displayed within 0.4 seconds from the time when the current speed value reaches the maximum speed value, real-time display is performed.

  Table 2 shows from the deceleration confirmation to the end of the first deceleration process.

［初回目の最低速度値の４秒間表示と最高速度値の初期化繰り返し］ 時刻１０．３秒（０．１秒クロック発生時）では減速確認情報Ａが送出されるため、次の０．１秒クロック発生時の時刻１０．４秒以降ではステップＳＰ２，ＳＰ１０に進むので、減速判定手段１は減速判定をしない。時点ｔ１１において現在速度値Ｖ_ｎが９６．０であると、時刻１０．３秒での最低速度値Ｖ_ＭＩＮが４００．０であるため、この現在速度値Ｖ_ｎの９６．０が最低速度値Ｖ_ＭＩＮとなり（ステップＳ４，Ｓ５）、またこの最低速度値の更新により最高速度値Ｖ_ＭＡＸがゼロに初期化されるが（ステップＳ６）、直ぐに最高速度値Ｖ_ＭＡＸと現在速度値Ｖ_ｎとが大小比較され（ステップＳ７）、最高速度値Ｖ_ＭＡＸが現在速度値Ｖ_ｎの９６．０となる。なお、表２中の括弧記号（）は最高速度値Ｖ_ＭＡＸをゼロ初期化した直後に現在速度値Ｖ_ｎとなることを表わす。このため、減速確認Ａの送出直後から最高速度値Ｖ_ＭＡＸは初回目の極大値たる１００．５にピークホールドされ続けずに済み、ゼロ値と現在速度値Ｖ_ｎの間を遷移し続けるので、次回最高速度値が初回目の最高速度値よりも低い場合でも次回最高速度値を間違い無く捉えることができる。時刻１０．３秒から４秒経過した時点（時刻１４．３秒）迄、最高速度値Ｖ_ＭＡＸの表示が続き、時点ｔ１８で現在速度値Ｖ_ｎである８９．０の表示に戻る。この後も減速が続き、時刻２０．０秒で減速終期となり、現在速度値Ｖ_ｎが極小値５０．０となるので、最低速度値Ｖ_ＭＩＮが５０．０で、最低速度値Ｖ_ＭＩＮ＋６が５６．０となる。

[Display of the first minimum speed value for 4 seconds and repeated initialization of the maximum speed value] Since the deceleration confirmation information A is transmitted at time 10.3 seconds (when 0.1 second clock is generated), the next 0.1 Since the process proceeds to steps SP2 and SP10 after the time 10.4 seconds when the second clock is generated, the deceleration determination means 1 does not determine deceleration. If the current speed value V _n is 96.0 at time t11, the minimum speed value V _MIN at the time 10.3 seconds is 400.0. Therefore, 96.0 of the current speed value V _n is the minimum speed value. V _MIN (steps S4 and S5), and the update of the minimum speed value initializes the maximum speed value V _MAX to zero (step S6). Immediately, the maximum speed value V _MAX and the current speed value V _n are obtained. The magnitudes are compared (step S7), and the maximum speed value V _MAX becomes 96.0, which is the current speed value V _n . Incidentally, Table 2 in parenthesis () represents the current that the velocity value V _n immediately after zero initializes the maximum speed value V _MAX. For this reason, immediately after the transmission of the deceleration confirmation A, the maximum speed value V _MAX does not have to be continuously peak-held at the first maximum value of 100.5, and the transition between the zero value and the current speed value V _n continues. Even when the next maximum speed value is lower than the first maximum speed value, the next maximum speed value can be definitely captured. The display of the maximum speed value V _MAX continues until 4 seconds have elapsed from time 10.3 seconds (time 14.3 seconds), and the display returns to the display of 89.0 that is the current speed value V _n at time t18. Also continued deceleration after this, become a deceleration end in time 20.0 seconds, the speed value _{V n} current is the minimum value 50.0, the lowest speed value _{V MIN} is 50.0, the lowest velocity value _{V MIN} +6 56.0.

  Table 3 shows the period from the second acceleration process to the acceleration confirmation.

［最低速度値の表示］ 時刻２０．０秒以降で第２回目の加速過程に入ると、最低速度値Ｖ_ＭＩＮは極小値５０．０にホールドされているが、現在速度値Ｖ_ｎ及び最高速度値Ｖ_ＭＡＸが漸増更新し、時刻２３．０秒において現在速度値Ｖ_ｎ及び最高速度値Ｖ_ＭＡＸが極小値５０に６を加えた閾値５６．０を超えると、加速判定手段１３が加速確認情報Ｂを送出するので、最小値たる最低速度値Ｖ_ＭＩＮの５０．０が表示されると共に、その旨の標識「Ｌ」が表示される。またこの表示の際にはアラーム音が鳴る。更に、減速判定手段１０がリセットされ、第２回目の減速過程のために待機する。

[Display of minimum speed value] When entering the second acceleration process after time 20.0 seconds, the minimum speed value V _MIN is held at the minimum value 50.0, but the current speed value V _n and the maximum speed are displayed. When the value V _MAX is gradually updated and the current speed value V _n and the maximum speed value V _MAX exceed the threshold value 56.0 obtained by adding 6 to the minimum value 50 at time 23.0 seconds, the acceleration determination unit 13 determines the acceleration confirmation information. Since B is transmitted, 50.0 of the minimum speed value V _{MIN which is} the minimum value is displayed, and a sign “L” to that effect is displayed. In this display, an alarm sounds. Furthermore, the deceleration determination means 10 is reset and waits for the second deceleration process.

  Table 4 shows the period after the second acceleration check.

［最低速度値の４秒間表示］ 時刻２３．０秒から４秒を経過する時点（２７．０秒）迄は、表示器６が最低速度値Ｖ_ＭＩＮの５０．０を表示し続け、時刻２７．０秒で現在速度値Ｖ_ｎ現の表示値６０．８に戻る。

[Display of Minimum Speed Value for 4 Seconds] The display device 6 continues to display 50.0 of the minimum speed value V _MIN until the time (27.0 seconds) when 4 seconds have elapsed from the time of 23.0 seconds. in 2.0 seconds, return to the current velocity value _{V n} the current display value 60.8.

In this example, the maximum speed value value V _MAX held by the maximum speed detection means 8 is displayed when the deceleration determination means 10 determines that the deceleration is confirmed in the deceleration process, and the hold value of the minimum speed detection means 9 is initialized to After preparing to capture the minimum speed value in the deceleration process, the holding value of the maximum speed detecting means 8 is initialized every time the holding value of the minimum speed detecting means 9 is updated, and at the time of the minimum speed value in the deceleration process. After the minimum speed value V _MIN is set as the initial value in the next acceleration process to the holding value of the maximum speed detecting means 8, the minimum speed detecting means 9 holds when the acceleration determining means 13 determines that the acceleration is confirmed. Since the minimum speed value V _MIN to be displayed is displayed, the maximum speed value V _MAX in each acceleration process and the minimum speed value V _MIN in each deceleration process can be alternately displayed in real time. In particular, in this example, since the deceleration determination means 10 and the acceleration determination means 13 are provided, based on only one system pulse from the pulse generation means 1, the maximum speed value (speed maximum value) and each deceleration in each acceleration process. The lowest speed value (minimum speed value) in the process can be displayed alternately in real time. In addition, since there is a maximum speed initialization means 12 that initializes the hold value of the maximum speed detection means 8 every time the minimum speed detection means 9 is updated, an error in the maximum speed value in the second and subsequent acceleration processes. The display can be eliminated.

It is a functional block diagram which shows the vehicle-mounted speedometer which concerns on the Example of this invention. It is a flowchart which shows the various initial settings and main routine of the microcomputer in the same in-vehicle speedometer. It is a flowchart which shows the pulse edge detection interruption routine of the microcomputer in the same in-vehicle speedometer. It is a flowchart of the 0.1 second timer interruption routine of the microcomputer in the same in-vehicle speedometer. It is a flowchart of the display interruption routine of the microcomputer in the same in-vehicle speedometer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Vehicle speed pulse generator 2 ... Waveform shaper 3 ... Speed value calculation means 4 ... Current speed storage means 5 ... Current speed display control means 6 ... Display 7 ... Drive circuit 8 ... Maximum speed detection means 9 ... Minimum speed Detection means 10 ... Deceleration determination means 11 ... Maximum speed display control means 12 ... Maximum speed initialization means 13 ... Acceleration determination means 14 ... Previous speed value storage means 15 ... 0.1 second clock means 16 ... Minimum speed display control means 17 ... Time resetting means 18 ... Sound generator A ... Deceleration confirmation information B ... Acceleration confirmation information V _n ... Current speed value V _n-1 ... Previous speed value V _MIN ... Minimum speed value V _MAX ... Maximum speed value

Claims (13)

A pulse generating means for generating a pulse at a time period corresponding to the rotational speed; a speed value calculating means for calculating a speed value based on the pulse width for each incoming pulse; and the speed value for each calculation of the speed value. A current speed storage means that updates and holds the current speed value, and a speed indicator that updates or displays the speed value every time the speed value is calculated,
A maximum speed detecting means for comparing the speed value with a holding value every time the speed value is calculated, and updating and holding the speed value as a maximum speed value when the speed value is equal to or greater than the holding value;
A deceleration determination means for comparing the deceleration information about the rotation speed with a predetermined deceleration determination criterion to determine whether or not deceleration confirmation is appropriate;
Maximum speed display control means for controlling the display to display or instruct the maximum speed value held by the maximum speed detection means within a first time period when the deceleration determination means determines the deceleration confirmation;
A maximum speed initialization means for initializing a holding value of the maximum speed detection means after the deceleration determination means determines that the deceleration is confirmed;
A speedometer characterized by comprising: 2. The maximum speed initialization unit according to claim 1, wherein after the deceleration determination unit determines that the deceleration is confirmed, the acceleration information relating to the rotational speed is compared with a predetermined acceleration criterion to determine whether the acceleration confirmation is appropriate. The speedometer is an acceleration determining means for initializing a held value of the maximum speed detecting means when the acceleration is confirmed. 2. The minimum speed detecting means according to claim 1, wherein each time the speed value is calculated, the speed value is compared with a hold value, and when the speed value is equal to or less than the hold value, the speed value is updated and held as the minimum speed value. The deceleration determining means initializes the holding value of the minimum speed detecting means when it is determined that the deceleration is confirmed, and the maximum speed initializing means is used when the update of the holding value of the minimum speed detecting means is stopped. A speedometer characterized by initializing a holding value of the maximum speed detecting means. A pulse generating means for generating a pulse at a time period corresponding to the rotational speed; a speed value calculating means for calculating a speed value based on the pulse width for each incoming pulse; and the speed for each calculation of the speed value. A speedometer having current speed storage means that updates and holds a value as a current speed value, and a visual indicator that updates or displays the speed value every time the speed value is calculated,
A maximum speed detecting means for comparing the speed value with a holding value every time the speed value is calculated, and updating and holding the speed value as a maximum speed value when the speed value is equal to or greater than the holding value;
A minimum speed detecting means for comparing the speed value with a holding value for each calculation of the speed value, and updating and holding the speed value as a minimum speed value when the speed value is equal to or less than the holding value;
Deceleration information for comparing the rotation speed with a predetermined deceleration determination criterion to determine whether or not deceleration confirmation is appropriate, and a deceleration determination means for initializing a holding value of the minimum speed detection means when the deceleration confirmation is determined;
Maximum speed display control means for controlling the display to display or instruct the maximum speed value held by the maximum speed detection means within a first time period when the deceleration determination means determines the deceleration confirmation;
A maximum speed initialization means for initializing the holding value of the maximum speed detecting means every time the holding value of the minimum speed detecting means is updated after the initialization of the minimum speed detecting means;
A speedometer characterized by comprising: 5. The maximum speed display control means according to claim 1, wherein the maximum speed display control means controls to display a sign indicating that the maximum speed is displayed when the maximum speed value is displayed or indicated by the visual indicator. A speedometer characterized by that. 6. The speedometer according to claim 1, wherein the deceleration information related to the rotational speed is a time series of the speed values obtained from the speed value calculating means. 7. The previous speed value storage means for updating and holding the speed value a predetermined time before the current speed value held by the current speed storage means as the previous speed value according to claim 6, wherein the deceleration determination means comprises: , A decrement value from the previous speed value to the current speed value is calculated at predetermined time intervals, and a comparison is made as to whether or not the decrement value is greater than or equal to a deceleration reference value. A speedometer having a deceleration degree determination means for determining deceleration confirmation. 7. The previous speed value storage means for updating and holding the speed value a predetermined time before the current speed value held by the current speed storage means as the previous speed value according to claim 6, wherein the deceleration determination means comprises: , A decrement value from the previous speed value to the current speed value is calculated at predetermined time intervals, and a comparison is made as to whether or not the decrement value is greater than or equal to a deceleration reference value. A degree-of-deceleration determination means for determining that there is deceleration; a number-of-determination means for determining that the deceleration is confirmed if the number of times that the deceleration is present is continuously counted in increments of the predetermined time and is equal to or greater than a reference number; A speedometer characterized by comprising: 9. The acceleration determination according to claim 4, wherein the deceleration determination means determines that the deceleration is confirmed, and then compares the acceleration information related to the rotational speed with a predetermined acceleration criterion to determine whether the acceleration is confirmed. And an acceleration determining means for controlling the minimum speed value held by the minimum speed detecting means when the acceleration determining means determines that the acceleration is confirmed to be displayed or instructed within a second time period by the visual indicator. A speedometer comprising speed display control means. 10. The speedometer according to claim 9, wherein the minimum speed display control means controls to display or indicate a sign indicating that the minimum speed value is the minimum speed when the minimum speed value is displayed or indicated by the discriminator. . 10. The speedometer according to claim 9, wherein the acceleration information related to the rotational speed is a time series of the speed values obtained from the speed value calculating means. 11. The acceleration determination unit according to claim 10, wherein the acceleration determination means calculates an increment value from the minimum speed value to the current speed value, compares the increment value with a magnitude of whether or not the increment value is equal to or greater than an acceleration reference value, and the increment value is an acceleration value. A speedometer comprising acceleration / deceleration degree determination means for determining that the acceleration is confirmed when the value is equal to or greater than a reference value. A pulse generating means for generating a pulse at a time period corresponding to the rotational speed; a speed value calculating means for calculating a speed value based on the pulse width for each incoming pulse; and the speed value for each calculation of the speed value. Current speed storage means that updates and holds the current speed value as a current speed value, and each time the speed value is calculated, the speed value is compared with the held value, and when the speed value is equal to or greater than the held value, the speed value is set as the maximum speed value. The maximum speed detection means for updating and holding, and the minimum speed for updating and holding the speed value as the minimum speed value when the speed value is smaller than or equal to the holding value every time the speed value is calculated. The maximum speed value held by the maximum speed detecting means is output when the detection means and deceleration confirmation information relating to the rotational speed are generated, and the held value of the minimum speed detecting means is initialized, and then the minimum speed detection is performed. Each time the holding value of the means is updated, the holding value of the maximum speed detecting means is initialized, and then the minimum speed value held by the minimum speed detecting means is output when acceleration confirmation information relating to the rotational speed is generated. A speedometer comprising control means.

Images