JP5501627B2 - Timekeeping error automatic correction system and timekeeping error automatic correction method - Google Patents

Description

  The present invention relates to a time error automatic correction system and a time error automatic correction method for automatically correcting a time error of a vehicle-mounted timepiece.

  Conventionally, as shown in FIG. 4 as an example of an in-vehicle timepiece system. In this timepiece system, for example, the oscillation of the oscillator 1 of 32 kHz is measured by an RTC (real-time clock) 2a of the CPU 2 and displayed on the display unit 3 of the timepiece that performs digital display. Note that power to the CPU 2 is supplied to the power supply terminal (Vcc) via the 5V power supply 4 connected to the on-vehicle battery (+ B).

  By the way, when the engine is started in a low battery voltage state, the electric power from the battery (+ B) is consumed by the ignition device or the like, so that the output voltage of the battery (+ B) may be significantly lower than when it is normal. At this time, if the output voltage of the battery (+ B) falls below a predetermined reset threshold in the power supply voltage monitoring unit 5 even for a moment, a reset signal is output from the power supply voltage monitoring unit 5 to the reset terminal (RST), and the CPU 2 resets. There is a possibility of going. In this case, the time measurement by the RTC 2a of the CPU 2 is stopped.

  As described above, when the CPU 2 resets when the engine is started in the low battery voltage state and the time measurement by the RTC 2a of the CPU 2 is repeatedly stopped, the time displayed on the display unit 3 is delayed. It is necessary to correct a time delay that is a time measurement error displayed on the display unit 3 by a time / minute adjustment switch (CLOCK SW) 6 connected to the CPU 2 via an I / F (interface) 7.

  In order to correct such a timing error, in Patent Document 1, a time reset switch is provided in addition to the conventional forward switch and reverse switch, and the time reset switch is pressed according to a radio time signal or the like. An analog timepiece is proposed in which the minute hand of the timepiece body is immediately moved and corrected to the hourly position by the pressing signal.

JP 05-005791 A

  By the way, in the analog timepiece shown in the above-mentioned Patent Document 1, when the clock indication value in the timepiece body is delayed or advanced, by pressing the hourly reset switch in accordance with the radio time signal, etc., Although the minute hand of the timepiece main body is immediately moved and corrected to the hourly position, there is a problem that it is necessary to press the hourly reset switch in accordance with a radio time signal or the like.

  The present invention has been made in view of such a situation, and even when the engine is started in a low battery voltage state, it is possible to automatically correct the time error of the on-vehicle clock. It is an object of the present invention to provide a system and an automatic time error correction method.

The timekeeping error automatic correction system of the present invention is a timekeeping error automatic correction system for correcting a timekeeping error of a vehicle-mounted watch, which operates using a vehicle-mounted battery as a power source and is based on the time measured. Display control means for controlling the time display to the display, storage means for storing the reset time quantified for each vehicle type indicating the time from the reset start to the reset end by the display control means, and the output voltage of the battery Output voltage monitoring means for outputting a reset signal that prompts the display control means to start resetting when the output voltage falls below a predetermined reset threshold, and the display control means is in a battery voltage low state. upon receipt of the reset signal when the engine is started, becomes reset start, after the reset completion, the stored in the storage means The set time is added to the time after the CPU returns and controls the time display.
Also, the timekeeping error automatic correction method of the present invention is a timekeeping error automatic correction method for correcting the timekeeping error of a vehicle-mounted watch, based on the time measured by the display control means that operates using a vehicle-mounted battery as a power source. The step of controlling the time display on the display unit of the timepiece and the output voltage monitoring means monitor the output voltage of the battery, and reset to the display control means when the output voltage falls below a predetermined reset threshold Outputting a reset signal for prompting the start, and the display control means starts resetting when receiving the reset signal at the time of engine start in a low battery voltage state, and resetting by the display control means after completion of resetting the reset time of the storage means quantified reset time for each vehicle model indicating the time to reset the start and end are stored By adding at a later time PU recovery and controls the time display.
In the timekeeping error automatic correction system and timekeeping error automatic correction method of the present invention, the time display on the display unit of the timepiece is controlled based on the time measured by the display control means that operates using a vehicle-mounted battery as a power source, and the output voltage The monitoring means monitors the output voltage of the battery, and when the output voltage falls below a predetermined reset threshold, the display control means outputs a reset signal for prompting the reset start, and the display control means outputs the reset signal. When it is received, the reset is started, and after the reset is completed, the reset time of the storage means in which the reset time quantified for each vehicle type indicating the time from the reset start to the reset end is stored is added to the time after the CPU returns. Since the time display is controlled, the stoppage time period during the resetting is complemented by the reset time.

According to the timekeeping error automatic correction system and the timekeeping error automatic correction method of the present invention, when the display control means receives a reset signal at the time of engine start in a low battery voltage state, the reset starts, and after the reset ends, the reset starts from the reset start. The reset time quantified for each vehicle type indicating the time until the end is stored. The reset time of the storage means that is stored is added to the time after returning to the CPU to control the time display, and the time stop period during reset is reset. Since it is complemented by time, even when the engine is started in a state where the battery voltage is low, the timing error of the in-vehicle timepiece can be automatically corrected.

It is a figure for demonstrating one Embodiment of the time-measurement-error automatic correction system of this invention. It is a figure for demonstrating the quantified reset time which shows the time from the reset start of CPU to the completion | finish of reset memorize | stored in the non-volatile memory of FIG. It is a flowchart for demonstrating the time error automatic correction method by CPU of FIG. It is a figure which shows an example of the timepiece system of the conventional automotive instrument.

  Details of the embodiment of the present invention will be described below. FIG. 1 is a diagram for explaining an embodiment of an automatic time error correction system according to the present invention.

  The timekeeping error automatic correction system shown in FIG. 1 includes an oscillator 10, a CPU 11, a display unit 12, a nonvolatile memory 13, a 5 V power supply 14, a power supply voltage monitoring unit 15, an hour / minute adjustment switch 16, and an I / F (interface) 17. I have.

  The oscillator 10 oscillates at 32 kHz, for example. The CPU 11 controls time display on the display unit 12 of the timepiece, has a power supply terminal (Vcc), a reset terminal (RST), and a ground terminal (GND), and further displays based on the frequency from the oscillator 10. An RTC (real-time clock) 11a that measures the time to be displayed on the unit 12 is incorporated. The display unit 12 performs digital display of the time counted by the RTC 11a.

  The nonvolatile memory 13 stores a quantified reset time indicating the time from the reset start of the CPU 11 to the end of reset.

  The 5V power supply 14 converts the voltage of the vehicle-mounted battery (+ B) to 5V and supplies it to the CPU 11. The power supply voltage monitoring unit 15 monitors the output voltage of the battery (+ B), and outputs a reset signal to the reset terminal (RST) of the CPU 11 when the output voltage falls below a predetermined reset threshold (for example, 7V).

  The hour / minute adjustment switch (CLOCK SW) 16 is operated when adjusting each of the hour digit and the minute digit of the time displayed on the display unit 12. An I / F (interface) 17 transmits an operation by the hour / minute adjustment switch 16 to the CPU 11.

  Next, the quantified reset time that indicates the time from the reset start of the CPU 11 to the end of reset stored in the nonvolatile memory 13 of FIG. 1 will be described with reference to FIG.

  Normally, in the case of a battery (+ B) having a rated voltage of 12 V, 13.5 V is output in a fully charged state or after the engine is started. In this state, since the battery is normal, even when the electric power from the battery (+ B) is consumed by the ignition device or the like when the engine is started, the output voltage of the battery (+ B) is the predetermined voltage of the power supply voltage monitoring unit 15. Since the reset signal is not output from the power supply voltage monitoring unit 15 to the reset terminal (RST), the CPU 11 does not start resetting.

  On the other hand, when the engine is started in a low battery voltage state, the power from the battery (+ B) is consumed by the ignition device or the like, so that the output voltage of the battery (+ B) is significantly lower than that in the normal state. If a predetermined reset threshold value (for example, 7V) in the power supply voltage monitoring unit 15 falls below even for a moment, a reset signal is output from the power supply voltage monitoring unit 15 to the reset terminal (RST), and the CPU 11 resets. There is.

  Therefore, the time (t2) from the time when the CPU 11 starts resetting (t1) to the time when the CPU 11 finishes resetting is quantified, and the quantified time is set as the reset time of the CPU 11 and stored in the nonvolatile memory 13 in advance. deep. This reset time is considered to be quantifiable for each vehicle type, and even if the CPU 11 repeats resetting, all the reset times are the same.

  As a result, the timing by the RTC 11 a is stopped until the CPU 11 starts resetting and ends, but the stop period is supplemented by the reset time of the CPU 11 stored in the nonvolatile memory 13 in advance.

  Next, with reference to FIG. 3, a time error automatic correction method by the CPU 11 of FIG. 1 is described. First, as described above, when the engine is started with the battery voltage lowered, the electric power from the battery (+ B) is consumed by the ignition device or the like, and the output voltage of the battery (+ B) is significantly lower than that in the normal state. When a predetermined reset threshold value (for example, 7 V) in the voltage monitoring unit 15 falls below even a moment, a reset signal is output from the power supply voltage monitoring unit 15 to the reset terminal (RST).

  At this time, the CPU 11 determines the presence or absence of a reset signal (step S1). If it is determined that there is a reset signal (step S1: YES), the reset is started (step S2).

  Next, when the reset is finished (step S3), the time stored in the nonvolatile memory 13 (the time before resetting) and the reset time already stored in the nonvolatile memory 13 are added (step S4). The added time is displayed on the display unit 12. As a result, the time delay displayed on the display unit 12 is automatically corrected. Thereafter, the time measured by the RTC 11a is displayed on the display unit 12.

  As described above, in the present embodiment, the CPU 11 that is a display control unit that operates using the on-vehicle battery (+ B) as a power source controls the time display on the display unit 12 of the clock based on the time measured, and the output voltage The output voltage of the battery (+ B) is monitored by the power supply voltage monitoring unit 15 which is a monitoring means, and when the output voltage falls below a predetermined reset threshold (for example, 7 V), a reset signal is output to prompt the CPU 11 to start resetting. Thus, when the CPU 11 receives the reset signal, the reset is started, and after the reset is completed, the nonvolatile memory 13 which is a storage means in which the quantified reset time indicating the time from the reset start to the reset end is stored. By adding the reset time to the time after returning to the CPU 11 and controlling the time display, Since the stop period has to be complemented by the reset time, even at engine start at low battery voltage condition, it can be corrected automatically counting clock error for vehicle.

10 Oscillator 11 CPU
12 Display Unit 13 Non-Volatile Memory 14 5V Power Supply 15 Power Supply Voltage Monitoring Unit 16 Time Adjustment Switch 17 I / F (Interface)

Claims (2)

An automatic time error correction system that corrects the time error of an on-vehicle watch,
Display control means for controlling the time display on the display unit of the timepiece based on the time measured while operating with the vehicle-mounted battery as a power source;
Storage means for storing the reset time quantified for each vehicle type indicating the time from the reset start to the reset end by the display control means;
Output voltage monitoring means for monitoring the output voltage of the battery, and outputting a reset signal that prompts the display control means to start resetting when the output voltage falls below a predetermined reset threshold;
When the display control means receives the reset signal when the engine is started in a low battery voltage state, the display control means starts resetting. After the reset is completed, the reset time stored in the storage means is added to the time after the CPU is restored. And a time error automatic correction system characterized by controlling the time display. It is a time error automatic correction method for correcting the time error of an on-vehicle watch,
A step of controlling the time display on the display unit of the timepiece based on the time measured by the display control means that operates using a vehicle-mounted battery as a power source; and
A step of monitoring the output voltage of the battery by an output voltage monitoring means, and outputting a reset signal for urging the display control means to start resetting when the output voltage falls below a predetermined reset threshold;
When the display control means receives the reset signal when starting the engine in a low battery voltage state, it starts resetting, and after the reset is completed , quantifies each vehicle type indicating the time from the reset start by the display control means to the end of reset. A time error automatic correction method comprising: controlling the time display by adding the reset time of the storage means in which the reset time is stored to the time after the CPU is restored.

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