JPH0582890B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a battery-powered measuring device that saves power and extends the life of the battery.

[Prior art]

Traditionally, battery-powered, portable measurement devices
In order to improve usability, the device is often kept in an active state without a power switch so that measurements can be taken at all times. Furthermore, even if a power switch is provided, if measurements are to be made frequently, it is cumbersome to operate the power switch at the start and end of each measurement, and the power switch may be left turned on. There are many things. In such devices, the challenge is how to extend the life of the battery without impairing its functionality.

[Problems to be solved by the invention]

However, as mentioned above, even though the actual measurement time is short, in order to improve usability, such devices are constantly supplied with power, which consumes more power than the actual working time. There is a problem with this. The present invention has been made to improve these drawbacks, and its purpose is to save power and extend the life of the battery without impairing the functionality of the device.

[Means to solve the problem]

The structure of the invention for solving the above problems is as follows. A device that operates according to commands stored in a storage device, comprising: a sensor that is sensitive to a measured quantity; a detection circuit that is connected to the sensor and that converts the sensitive state quantity of the sensor into an electrical signal and outputs the electrical signal; A central processing unit that has a normal operating mode in which it is in a normal operating state and a low power consumption mode that consumes less power than the normal operating mode and stops operating, and a storage device that stores operating procedures of the central processing unit in the form of command words. The central processing unit inputs the signal from the detection circuit and calculates the measured value from the signal,
a command control unit that commands a series of processing to output a display signal for displaying a display value corresponding to the measured value; and a command control unit that commands a series of processing to output a display signal for displaying a display value corresponding to the measured value; A timing signal generation circuit that is applied to the device; a latch circuit that holds display signals from the central processing unit; a display that displays measured values according to the output of the latch circuit; The command control unit consists of a switching circuit that controls the power supply to the detection circuit by conducting or cutting it off depending on the situation, and a battery that is the drive source for the detection circuit, central processing unit, and display. A mode control section that switches the central processing unit to a low power consumption mode intermittently in synchronization with the normal operation mode and operates according to the command control section, and then puts the central processing unit into a low power consumption mode. When in the operation mode, there is a determination unit that determines the magnitude of the temporal fluctuation rate of the measured value from the detection circuit, and when the determination unit determines that the temporal fluctuation rate of the measured value is smaller than a predetermined value. , Outputs a control signal to the switching circuit so that the central processing unit supplies power to the detection circuit for only one period out of the periods in which the synchronization signal is inputted several times to detect the measured value, and controls the temporal fluctuation of the measured value. A power supply control unit that continuously supplies power to the detection circuit when the rate is determined to be above a predetermined value, and a power supply control unit that continuously supplies power to the detection circuit when the determination unit determines that the temporal fluctuation rate of the measured value is smaller than the predetermined value. The device is characterized by having a measured value processing unit that inputs a signal from the detection circuit in synchronization with the input of the next synchronization signal after power supply is started, and calculates a measured value from the signal. .

[Effect]

The central processing unit is normally in a low power consumption mode, in which power consumption is lower, and its operation is stopped by the mode control unit. When the synchronization signal is input from the timing signal generation circuit to the central processing unit,
The central processing unit changes from the low power consumption mode in which the operation is stopped to the normal operation mode, and then inputs the signal from the detection circuit according to the command from the command control unit and performs measurement after predetermined processing. Executes the process of outputting a display signal to the latch circuit to display the value. After the completion of one cycle of processing, the central processing unit changes from the normal operation mode to the low power consumption mode in which the operation is stopped by the action of the mode control unit. The central processing unit continues in the low power consumption mode until the next synchronization signal is output from the timing signal generation circuit. Here, the operation time in the normal operation mode required to execute a series of processes is very small compared to the period of the synchronization signal. Therefore, the central processing unit synchronizes with the synchronization signal that is periodically output.
It only operates intermittently to perform measurement processing. That is, sampling and measurement are performed, and the central processing unit is kept in the normal operation mode for only a short period of time necessary for the processing. Therefore, power consumption becomes intermittent, and the life of the battery can be extended. During normal measurement, power is continuously supplied to the detection circuit by the power supply control unit, and as mentioned above, one measurement is performed for each synchronization signal input. . Furthermore, in the present invention, it is determined whether the measuring device is in a measuring state or in a non-measuring state, that is, in an idle state, and when the measuring device is in an idle state, the power supply to the detection circuit is intermittently due to the action of the power supply control section. , Furthermore, power saving is achieved. The determination unit determines the temporal fluctuation rate of the measured value. A small temporal variation rate means that the measuring device is not in a measuring state. In other words, it can be considered to be in an abandoned state. Therefore, in that case, the power supply control unit supplies power to the detection circuit only for one period for several synchronization signal inputs, thereby performing intermittent power supply. Therefore, when in an idle state, measurements are not performed every time a synchronization signal is input, but every time the detection circuit becomes active for measurement, that is, the next synchronization after intermittent power supply to the detection circuit has started. The measurement value processing section executes measurement at the input timing of the signal. Thereby, power is supplied to the detection circuit, and a measurement value is obtained in a state where the power supply state and the temperature state of the element are stable. On the other hand, when the temporal fluctuation rate of the measured value is larger than the predetermined value, it is assumed that the detection circuit is in the measurement state, and the detection circuit is continuously supplied with power, and is
measurements are taken. In this manner, when the measuring device is left unused, power is supplied to the detection circuit intermittently, which further improves the power saving effect and extends the life of the battery.

【Example】

The present invention will be explained below based on specific examples. The measuring device of this embodiment relates to an inner diameter measuring device. FIG. 1 is a partial sectional view showing the configuration of an inner diameter measuring device according to an embodiment, and FIG. 5 is a block diagram showing the electrical configuration of the device.
In the figure, 1 is a measuring head, 3 is a gripping part, and 5 is a display head. Cylindrical side surface 10 of the measuring head
is fitted into the tubular measuring object 2. Cylindrical side 1
0 is provided with a pair of windows 11a and 11b on the diameter line, and contacts 12a and 11b are provided through the windows.
12b is provided movably in the X-axis direction.
The contacts 12a, 12b are screwed into movable levers 13a, 13b by screws 14a, 14b. The contacts 12a and 12b are screwed into the screw 1 so that the contact surfaces 120a and 120b at the tip thereof protrude from the cylindrical side surface 10 and come into contact with the wall surface 2a of the measurement object 2.
4a and b. Movable lever 13a,
13b is a support plate 1 which is one of the elastic members.
5, and its support plate 15 is fixed to a fixing block 31 protruding from the side wall 30 of the grip part 3. Also, both movable levers 13
a and 13b are elastically coupled by a coil spring 17, which is another elastic member. When the measuring head 1 is fitted onto the object 2 and the contacts 12a, b abut against the wall surface 2a of the object 2 and are pushed inward, the flexible portions 16a, b of the support plate 15 bend inward and , the coil spring 17 is compressed and the contacts 12a, b are biased outward. Therefore, the contact surfaces 120a, b accurately contact the wall surface 2a of the object to be measured. A tube body 24 is fixed to the movable lever 13b, and a detection coil 21 is installed inside the tube body 24.
is installed. On the other hand, a rod 23 is fixedly attached to the movable lever 13a.
A core 22 is fixedly installed at the tip of 3. core 2
The relative position of the coil 21 and the movable lever 13
The spacing between a, b and therefore the contacts 12a,b
It changes in proportion to the interval between. In the displacement sensor 20 having such a configuration, the inductance changes depending on the position of the core 22 with respect to the coil 21, and the change is detected as an amount of electricity. The measuring head 1 and the gripping part 3 have flanges 18 and 3.
2, and is removably connected by a bolt 33. Coil 21 is connected to displacement detection circuit 40 . As a mechanical attachment/detachment mechanism between the display head 5 and the grip portion 3, a flange 36 formed integrally with the display head 5 and a fixing ring 37 rotatable with respect to the flange and threaded on the inner surface are provided. ing. The flange 36 abuts the end of the side wall 30, and the fixing ring 37 is threadedly engaged with a screw formed in the side wall 30. The display head 5 and the grip 3 are aligned by the locking plate 59 coming into contact with the locking plates 39a, 39b on the side of the grip 3.
Furthermore, the grip portion 3 and the display head 5 are connected to the connector 34,
It is electrically connected by 35. Inside the grip part 3, in addition to the displacement detection circuit 40, a battery 44,
A switching circuit 42 that controls power supply to the displacement detection circuit 40 using a control signal from the CPU 50
and are provided. On the other hand, the front surface of the display head 5 is provided with a display panel 54 and an input switch 56 for setting the operating mode. Inside the display head 5, a CPU 50, a timing signal generation circuit 58 connected thereto, a ROM 55, a RAM 57,
A latch circuit 53, a drive circuit 52, and a capacitor 51 charged from a battery 44 are provided. The ROM 55 stores command words for controlling the device. When the display head 5 is electrically connected to the gripping part 3, the devices provided in the display head 5 are powered by the battery 44, and the display head 5 is electrically disconnected from the gripping part 3. When the power is on, power is supplied by the charged capacitor 51. Therefore, even when the display head 5 is removed, the measured values can continue to be displayed on the display panel. In Figure 5, 34a-e, 35
a to e are terminals of connectors 34 and 35. Further, the output signal of the timing signal generation circuit 58 is
Connector terminals 35e, 34e, short circuit line 340,
Interrupt input terminal via terminals 34d and 35d
Entering into NMI. By doing so, when the display head 5 is removed, the synchronization signal is not input to the CPU 50, so that the CPU 50 can be automatically stopped in a low power consumption mode as described later. In such a configuration, the operation of the present device will be explained based on the flowchart in FIG. 6 and the timing charts in FIGS. 7 and 8. (1) When in the measurement state When the CPU 50 inputs the synchronization signal S1 every 0.5 seconds (time t1), it enters the normal operating state and starts the step.
Perform 100 or less. In step 100, the temporal variation rate D of the measured values is calculated. In step 102,
When the value D is larger than 1 μm/30 sec, it is determined that the measurement state is established. At that time, steps 104 and subsequent steps are executed. The CPU 50 is a switching circuit 42
outputs a power supply on signal to activate the displacement detection circuit 40, inputs a signal from the displacement detection circuit 40, executes predetermined arithmetic processing according to the signal, calculates a display value, and outputs a display signal. Latch circuit 53
(steps 104 to 114). Due to this action, the measured value is displayed on the display panel 54. Thereafter, the CPU 50 stops (time t2) and enters the low power consumption mode (step 116). Even if the CPU 50 is in the low power consumption mode, the displayed value is held by the latch circuit 52, so the display will not disappear. Furthermore, the switching circuit 42 has a latch function, and once a power supply on signal or a power supply off signal is input, the switching circuit 42 remains in a power supply state or a power cutoff state until the next power supply OFF signal or power supply ON signal is input, respectively. is maintained. In this way, the central processing unit repeats the above processing, enters the normal operation mode intermittently every 0.5 seconds, executes measurement and display processing, and stops after completing the processing, as shown in Figure 7. and enters low power consumption mode. Therefore, average power consumption can be reduced. (2) When the device is left unused When the device is left unused, in step 102, the temporal fluctuation rate D of the measured value becomes smaller than a predetermined value.
In that case, the processing from step 118 onwards is executed. C is a counter for controlling intermittent power supply to the displacement detection circuit 40, and is set to 1 by a synchronizing signal.
It is updated every time the cycle process is executed (step 126). Also, in the measurement state, the counter C
is set to zero (step 105), and the initial value of C is zero when the measurement state changes to the left state. Further, in the left state, C updates the values from 1 to 4 according to the synchronization signal and repeats it.
During the period when C becomes 3 to 4, the displacement detection circuit 40 enters the power supply state. The measurement and display processing is performed in the cycle in which C is 4. First, when the measurement state changes to the left state, in step 122, a power supply OFF signal is output to the switching circuit 42, the counter C is updated, and the displacement detection circuit 40 enters the power cutoff state (time t2). then 1.5
After seconds have elapsed and three synchronization signals are input, until the value of counter C reaches 3, the displacement detection circuit 40
No power is supplied, and the CPU does not perform measurement calculation processing. When counter C becomes 3, step 124
Then, a power supply on signal is output to the switching circuit 42 to activate the displacement detection circuit 40 (at the time
t3). Next, when the counter C becomes 4, step 106
After the measurement and display processing of ~114, in step 128,
Outputs a power supply off signal to the switching circuit 42,
Power supply to the displacement detection circuit 40 is stopped (time t4).
Then, in step 130, counter C is set to 1. Thereafter, the above-described process is executed, with one cycle consisting of four processes performed each time a synchronization signal is input. In this way, when left unused, the displacement detection circuit 40
is only powered for 0.5 seconds out of 2 seconds,
Measurements are taken at 2 second intervals. Therefore, power is saved when the measuring device is not in use. Further, when the temporal fluctuation rate of the measured value becomes larger than a predetermined value during the above-described idle state processing, power is immediately supplied to the displacement detection circuit 40, and the measurement state processing is executed. Furthermore, even if the measurement is in progress, if the temporal fluctuation rate of the measured value is smaller than a predetermined value, the idle state processing will be executed, but the measured value may be considered to have already stabilized. It is possible to perform intermittent movements without causing any problems. This device can be used by integrating the display head 5 with the grip 3 as shown in FIG. 3, or by removing the display head 5 from the grip 3 as shown in FIG. When the display head 5 is removed, the display head 5 and the grip part 3 are
The present device can be operated by electrically connecting with a relay cable 60 shown in the figure.
The relay cable 60 has a plug 62 and a socket 64.
The plug 62 engages with the grip 3 and the socket 64 engages with the display head 5. A connector 66 of the plug 62 is electrically connected to the connector 34 of the grip part 3. Also, the connector 68 of the socket 64 is connected to the connector 35 of the display head 5. The plug 62 has a support tube 70 and a fixing ring 72 rotatably engaged therewith. The inner wall of the fixing ring 72 is threaded, and it screws into the side wall 30 of the gripping part 3. Further, a locking plate 74 is provided at the center of the plug 62 in order to prevent rotation of the support tube 70 when the plug 62 is screwed onto the gripping part 3. Locking plates 39a, b provided in section 3
It comes into contact with and is locked. On the other hand, the socket 64 is
It has a support cylinder 80 with a screw 81 cut on its outer surface, into which the fixing ring 37 of the display head 5 is screwed. Then, the locking plate 59 of the display head 5
The display head 5 is prevented from rotating when the fixing ring 37 is screwed into the socket 64 by coming into contact with the locking plates 83a and 83b of the socket 64. Note that the correspondence between the scope of claims and the above embodiments is as follows. The sensor is a displacement sensor 20, the detection circuit is a displacement detection circuit 40, the storage device is a ROM 55,
The central processing unit is CPU50, and the command control unit is ROM5.
5 and a program written in command words stored in the ROM 55, the timing signal generation circuit is the timing signal generation circuit 58, the latch circuit is the latch circuit 53, the display is the drive circuit 52 and the display panel 5.
4. The switching circuit is a switching circuit 42,
The mode control section is a function of the CPU 50, the determination section is at steps 100 and 102 in FIG. 6, and the power supply control section is at step 6.
Steps 104, 115 and 118 in the diagram
~130, the measured value processing section corresponds to steps 106, 108 and step 120, respectively.

【Effect of the invention】

As described above, the present invention operates the central processing unit intermittently in synchronization with a synchronization signal of a constant period, and during the remaining free time, the central processing unit is stopped and placed in a low power consumption mode. When the temporal fluctuation rate of the measured value is smaller than a predetermined value, it is determined that the measuring device is in an idle state, and the power supply to the detection circuit is changed from continuous power supply to power supply for only one cycle out of several cycles of the synchronization signal. The device is characterized in that it switches to intermittent power supply and performs measurement in an idle state at the timing when the next synchronization signal is input after power is supplied to the detection circuit. Therefore, since the central processing unit operates intermittently for a short period of time in synchronization with the synchronization signal, average power consumption can be reduced. Further, when the device is left unused, power is supplied to the detection circuit intermittently, so that further power saving effect can be achieved and the life of the battery can be extended.
In addition, when left unattended, the measurement value is detected at the timing of the next synchronization signal input after power is supplied to the detection circuit, so even with intermittent power supply, the electrical and thermal conditions of the detection circuit are stable. It is possible to obtain a measured value after the process has been carried out, and the accuracy of the measured value in the unused state is improved. Because of this effect, it is not necessary to provide the present device with a power switch, and the usability of the device is improved.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view showing the configuration of an inner diameter measuring device according to a specific embodiment of the present invention, FIG. 2 is a partial cross-sectional view showing the configuration of a relay cable, FIG. FIG. 4 is an explanatory diagram showing how the device is used, and FIG. 5 is a block diagram showing the electrical configuration of the device. FIG. 6 is a flowchart showing the processing procedure of the CPU, and FIGS. 7 and 8 are characteristic diagrams showing the temporal characteristics of the current consumption of the embodiment device. DESCRIPTION OF SYMBOLS 1...Measuring head, 2...Measurement object, 3...Gripping part, 5...Display head, 10...Cylindrical side surface, 12
a, b...contact, 13a, b...movable lever,
15...Support plate, 21...Detection coil, 2
2... Core, 34, 35, 66, 68... Connector, 37, 72... Fixing ring, 39a, b, 5
9, 74, 83a, b...locking plate, 60...relay cable, 62...plug, 64...outlet.

Claims (1)

[Scope of Claims] 1. A sensor sensitive to a measured quantity; a detection circuit connected to the sensor that converts the sensitive state quantity of the sensor into an electrical signal and outputs the electrical signal; a central processing unit that operates in a normal operating state and a low power consumption mode that consumes less power than the normal operating mode and stops operating; and the operation of the central processing unit. It consists of a storage device that stores procedures in command words, and the central processing unit inputs the signal from the detection circuit, calculates a measured value from the signal, and displays a display value corresponding to the measured value. a command control unit that instructs a series of processing for outputting a display signal; and a timing signal generation circuit that provides a synchronization signal to the central processing unit to intermittently put the central processing unit into a normal operation mode. , a latch circuit that holds a display signal from the central processing unit; a display that displays a measured value according to the output of the latch circuit; and a display that is turned on or off according to the signal from the central processing unit to The command control unit includes a switching circuit that controls power supply to the detection circuit, and a battery that is a drive source for the detection circuit, the central processing unit, and the display unit. a mode control unit that intermittently periodically switches the central processing unit into a normal operation mode, operates according to the command control unit, and then puts the central processing unit into a low power consumption mode; and this mode control unit causes the central processing unit to operate normally. mode, a determination unit that determines the magnitude of the temporal fluctuation rate of the measured value from the detection circuit; and when the determination unit determines that the temporal fluctuation rate of the measured value is smaller than a predetermined value. outputs a control signal to the switching circuit so that the central processing unit supplies power to the detection circuit for only one period out of the periods in which the synchronization signal is inputted several times to detect a measured value; a power supply control section that continuously supplies power to the detection circuit when the temporal fluctuation rate of the measured value is determined to be greater than or equal to a predetermined value; and a power supply control section that continuously supplies power to the detection circuit when the temporal fluctuation rate of the measured value is determined to be smaller than the predetermined value. When the power supply is started to the detection circuit, input the signal from the detection circuit in synchronization with the input of the next synchronization signal,
A measuring device comprising: a measured value processing section that calculates a measured value from the signal.