JP2006118960A - Apparatus for counting rotation speed of rotator, its method, and rotator control apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform wide-range and highly precise rotation speed count. <P>SOLUTION: Rotation pulses output at a period according to the rotation speed of a rotator are input. Clock pulses generated at a period shorter than that of the rotation pulses are counted during one period of the rotation pulses. The number of counted clock pulses is latched. The latched number of clock pulses is cumulatively subtracted from the number of clock pulses set as the number of clock pulses generated in a unit of time. The number of times of subtractions performed in the unit of time is counted. On the basis of the counted number, the rotation speed of the rotator is counted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotational speed counting device for a rotating body, a method thereof, and a rotating body control device capable of counting rotational speed with a wide range and high accuracy only by using a general-purpose digital IC without performing a rotational speed calculation by a microcomputer. About.

In devices that control rotating bodies such as automobile internal combustion engines, wheel antilock brake systems, and drive motors, the number of rotations of these devices during operation is converted to digital data of an arbitrary number of bits based on detection signals obtained from sensors. It is digitized and this digital data is used for rotating body control. Since the rotational speed is required to be detected with high accuracy from low speed to high speed, for example, in the invention described in Patent Document 1 below, in order to enable calculation from a low rotational speed region to a high rotational speed region. , “A rotation sensor that generates a detection pulse according to the rotation speed, and a microcomputer that calculates the rotation speed based on the detection pulse and controls the engine, the detection pulse includes a plurality of pulse sequences, Select one pulse sequence from a plurality of pulse sequences according to the operating region of the engine, and calculate the rotation speed related to the engine based on the detection time and the number of pulses of the selected pulse sequence. The high rotation speed region that can be calculated by an easy process is expanded without changing the cycle and without impairing the calculation capability for the low rotation speed region.
JP 2000-310151 A

  However, even with the conventional invention including the invention described in the above cited document, the computational load of the microcomputer increases as the rotation speed increases, so the rotational speed detection accuracy and the detectable area are After all, it depends on the processing power of the microcomputer.

  The present invention has been made in view of the above-described problems of the prior art, and it is possible to perform a wide range and high-precision rotation speed only by using a general-purpose digital IC without performing a rotation speed calculation by a microcomputer. An object of the present invention is to provide a rotating body rotation speed counting device and method, and a rotating body control device capable of counting.

  In order to achieve the above object, a rotation speed counter for a rotating body according to the present invention comprises a rotation pulse input means for inputting a rotation pulse output at a cycle corresponding to the rotation speed of the rotation body, and a cycle of the rotation pulse. A clock pulse generator for generating clock pulses with a short period, a period measuring counter for counting the number of clock pulses generated during one period of the rotation pulse, and a clock pulse counted by the period measuring counter A frequency dividing counter that latches the number of clocks, a conversion coefficient setting counter that sets the number of clock pulses generated within a unit time from the clock pulse generator, and a rotation pulse input means each time a rotation pulse is input. From the number of clock pulses set in the conversion coefficient setting counter, the clock latched in the frequency division counter is set. Subtracting means for cumulatively subtracting the number of pulses, and counting means for counting the number of subtractions performed by the subtracting means within the unit time and counting the rotational speed of the rotating body from the counted number. Features.

  In order to achieve the above object, a rotational speed counter for a rotating body according to the present invention comprises: a rotational pulse input means for inputting rotational pulses output at a cycle according to the rotational speed of the rotating body; A high-speed clock pulse generator that generates a high-speed clock pulse having a frequency that is a multiple of the frequency of the clock pulse generated by the clock pulse generator described above, a clock pulse divider that divides the high-speed clock pulse, A period measurement counter that counts the number of divided clock pulses generated during one period of the rotation pulse, a latch unit that temporarily stores the number of clock pulses counted by the period measurement counter, A frequency division counter that latches the number of clock pulses stored in the latch unit, and within a unit time from the high-speed clock pulse generation unit A conversion coefficient setting counter for setting the number of clock pulses after frequency division of the generated high-speed clock pulse, and a high-speed clock generated by the high-speed clock pulse generator each time the rotation pulse input means inputs a rotation pulse. Subtracting means for cumulatively subtracting the number of clock pulses latched in the frequency dividing counter from the number of clock pulses set in the conversion coefficient setting counter based on the pulse; and And counting means for counting the number of subtractions performed in time and counting the rotational speed of the rotating body from the counted number.

  Furthermore, a rotating body control device according to the present invention for achieving the above object is characterized in that the rotating speed counting device according to claim 1 or 2 is a rotating pulse that generates a rotating pulse at a cycle corresponding to the rotating speed of the rotating body. It is connected between the detection means and a computer that controls the rotating body.

  In order to achieve the above object, a rotational speed counting method for a rotating body according to the present invention includes a step of inputting a rotational pulse output at a period corresponding to the rotational speed of the rotating body, and a period shorter than the period of the rotational pulse. Generating a clock pulse, counting the number of clock pulses generated during one period of the rotation pulse, latching the counted number of clock pulses, and generating within a unit time A step of setting the number of clock pulses, a step of cumulatively subtracting the number of clock pulses latched from the number of clock pulses set each time the rotation pulse is input, and a unit time. Counting the number of subtractions, and counting the rotational speed of the rotating body from the counted number.

  A method for counting the rotational speed of a rotating body according to the present invention for achieving the above object comprises the steps of inputting rotational pulses output at a period corresponding to the rotational speed of the rotating body, and the clock according to claim 9. A step of generating a high-speed clock pulse having a frequency that is a multiple of the frequency of the pulse, a step of dividing the high-speed clock pulse, and the number of divided clock pulses generated during one period of the rotation pulse. A step of counting, a step of temporarily storing the counted number of clock pulses, a step of latching the number of temporarily stored clock pulses, and a fraction of high-speed clock pulses generated within a unit time. The step of setting the number of clock pulses after the lap and the number of clock pulses set based on the high-speed clock pulse each time the rotation pulse is input A step of cumulatively subtracting the number of clock pulses latched, and a step of counting the number of subtractions performed within a unit time and counting the rotational speed of the rotating body from the counted number. Do

  According to the rotational speed counting device and method for a rotating body according to the present invention configured as described above, a wide range and high-precision rotation can be performed by using a general-purpose digital IC without performing a rotational speed calculation by a microcomputer. Speed counting is possible.

  Further, according to the rotating body control device according to the present invention configured as described above, the rotational speed of the rotating body is counted at the front stage of the computer, so that the computer can afford its computing capacity and the processing load of the computer. Is greatly reduced.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotating body rotation speed counting device and method and a rotating body control device according to the present invention will be described below in detail with reference to the drawings. In this specification, the rotating body control device will be described first, and then the rotating speed counting device and method of the rotating body will be described. In addition, the rotational speed counting device and the method of the rotating body will be described separately in [Embodiment 1] and [Embodiment 2].

  FIG. 1 is a schematic configuration diagram of a rotating body control device according to the present invention. In the present embodiment, an automobile engine is illustrated as an example of a rotating body, but the rotating body is not limited to this, and may be, for example, a drive motor for an electric vehicle or a wheel of a wheel antilock brake system.

  A water temperature sensor, a throttle sensor, a knock sensor, an intake air temperature sensor, and a rotation detection sensor 200 provided in the engine 210 are connected to the engine control device 100. The engine control apparatus 100 performs intake / exhaust valve control, ignition control, canister purge control, and air-fuel ratio control of the engine 210 based on signals input from these sensors. Furthermore, the engine control device 100 performs electrical signal communication with other control devices such as communication control, A / T (automatic transmission), and ABS (anti-lock brake system).

  The rotation detection sensor 200 is a sensor composed of an electromagnetic pickup, and is disposed opposite to the signal plate 220 attached to the crankshaft or camshaft of the engine 210. Is generated.

  The engine control apparatus 100 receives a signal shaper 110 that converts an analog rotation signal output from the rotation detection sensor 200 into a digital signal and a digital signal output from the signal shaper 110, that is, a rotation pulse. , A rotation speed counting device 120 that calculates the rotation speed of the engine 210 in hardware from the cycle of the input rotation pulse, and a computer 130 that performs calculation of main control performed by the engine control device 100 are provided. The computer 130 is a Y-chip microcomputer, and the rotation detection sensor 200, the signal plate 220, and the signal shaper 110 function as rotation pulse detection means.

  The rotational speed counting device 120 according to the present invention is connected between the signal shaper 110 and the computer 130, and receives rotational pulses output at a cycle corresponding to the rotational speed of the engine 210, so that the engine 210 has a hardware configuration. The rotational speed is counted at high speed, and the count result is output to the computer 130.

  According to the rotating body control device of the present invention, the rotational speed of the rotating body, that is, the engine 210 is not calculated by the computer 130 but is counted by the rotational speed counting device 120, so that the burden on the computer 130 is greatly reduced. be able to. Therefore, if the calculation amount required for controlling the engine 210 is the same as the conventional calculation amount, the performance of the computer 130 can be reduced. Conversely, if the computer 130 having the same performance as the conventional one is used, the burden is reduced. The control accuracy of the engine 210 can be improved by that amount.

Next, the rotational speed counting device for a rotating body according to the present invention will be described.
[Embodiment 1]
FIG. 2 is a block diagram showing the configuration of the rotational speed counting device 120 for a rotating body according to the present invention. The rotational speed counting device 120 is connected to the data bus line 140 (see FIG. 1) of the computer 130, and the rotational speed counting result of the engine 210 is output to the computer 130 via the data bus line 140.

  As shown in FIG. 2, the rotation speed counter 120 includes a timing control circuit 121, a clock pulse generator 122, a period measurement counter 123, a frequency division counter 124, a conversion coefficient setting counter 125, a rotation speed data counter 126, 3 A state register 127 is provided. As described above, most of the components of the rotation speed counting device 120 are constituted by a hard counter, and the rotation speed of the engine 210 can be counted by counting up and counting down the clock pulses. The timing control circuit 121 performs some software processing, but the processing is very slight.

  The timing control circuit 121 includes a rotation pulse input unit that inputs rotation pulses output at a cycle corresponding to the rotation speed of the engine 210 via the rotation detection sensor 200 that detects the rotation speed of the engine 210 and the signal shaper 110. ing. In addition, the timing control circuit 121 gives various instructions to a counter and a register (described later) connected to the timing control circuit 121 and controls their operation order.

  The clock pulse generator 122 generates clock pulses at a cycle shorter than the cycle of the rotation pulse input to the timing control circuit 121. The frequency of the clock pulse is determined by the measurement range of the rotational speed of the engine 210 and the required measurement accuracy, and is a pulse having a frequency of, for example, 200 kHz.

  The period measurement counter 123 counts clock pulses from the rising edge of the rotation pulse controlled and generated by the timing control circuit 121 to the next rising edge. The count value is held until a reset instruction is issued from the timing control circuit 121, and the count value is reset based on the instruction. Therefore, the period measurement counter 123 counts the number of clock pulses generated during one rotation pulse period.

  The frequency division counter 124 loads the number of clock pulses counted by the period measurement counter 123 based on the instruction output from the timing control circuit 121. The number of loaded clock pulses is subtracted based on the clock pulse output from the timing control circuit 121. When the number of clock pulses loaded is continued to 0 after subtraction, an increment instruction is output to a later-described rotation number data counter, and at the same time, a reload request is made to the timing control circuit 121.

The conversion coefficient setting counter 125 sets the number of clock pulses generated within a unit time from the clock pulse generator 122 based on a setting command for the number of clock pulses output from the timing control circuit 121. The set number of clock pulses is subtracted by the clock pulse output from the timing control circuit 121. Further, when the subtraction is continued and the number of set clock pulses becomes zero, a zero value instruction is output to the timing control circuit 121. For example, as described above, if the frequency of the clock pulse output from the clock pulse generator 122 is 200 kHz, the conversion coefficient setting counter 125 has the number of clock pulses for a unit time of 60 seconds, 200 kHz × 60 sec = A value of 1.2 × 10 ⁶ is set as the number of clock pulses.

  The rotation number data counter 126 increments the count every time an increment instruction is output from the frequency division counter 124. When a reset instruction is issued from the timing control circuit 121, the count is reset based on the instruction.

  The 3-state register 127 latches the count number of the rotation speed data counter 126 and outputs the count number to the computer 130. The count number of the 3-state register 127 represents the rotational speed of the engine 210 as it is.

  The period measurement counter 123, the frequency division counter 124, the conversion coefficient setting counter 125, and the rotation number data counter 126 constituting the counting means are all configured using only a general-purpose counter having a predetermined number of bits, and the number of bits is As a result, it is determined based on the measurement range of the rotational speed of the engine 210 and the required measurement accuracy. Note that the 3-state register 127 may not use a counter.

For example, in the above case, if the measurement range of the engine rotation speed is 60 rpm (frequency 1 Hz) to 12000 rpm (frequency 200 Hz) and the required measurement accuracy is 0.1%, the clock pulse generated by the clock pulse generator 122 is generated. The frequency of is 200 Hz × 1000 = 200 kHz. Therefore, since the frequency measurement counter 123 and the frequency division counter 124 must be able to count the same number of clock pulses, the number of bits that can count at least 2 × 10 ⁵ is required, and 18 bits or more. It is necessary to use a counter. The conversion coefficient setting counter 125 needs a number of bits that can count at least 60 × 2 × 10 ⁵ = 12 × 10 ⁶ in order to enable rpm display. Must be used. Further, the rotation speed data counter 126 needs a bit number that can count up to 12000 rpm, and it is necessary to use a counter of 14 bits or more. As described above, the necessary number of bits of the counter and the register is determined based on the measurement range of the rotational speed of the engine 210 and the required measurement accuracy.

  Since the rotational speed counting device 120 of the rotating body according to the present invention counts the rotational speed of the engine 210 at the front stage of the computer 130, the computer 130 is based on the measurement of the period of the rotational pulse and the measured period as in the prior art. This frees you from processing related to the calculation of the engine speed, the storage of the calculation results, and the use of counters, so that the calculation capacity can be afforded and the processing load on the computer 130 is greatly reduced. In addition, since it is only necessary to use a counter and register with the number of bits determined from the measurement range and measurement accuracy, high-accuracy measurement can be performed in a wide range of rotation speeds from a low rotation speed range to a high rotation speed range. This can be done according to the configuration. Furthermore, in this embodiment, five general-purpose counter ICs are used, and the rotational speed of the engine 210 can be accurately grasped even if the clock pulse output from the clock pulse generator 122 is not necessarily accurate. Since the clock pulse generator 122 does not have to generate a clock pulse with an accurate period, a low-cost clock pulse generator can be used. The rotational speed counting device 120 of the rotating body according to the present invention is simple in design and can be easily designed, and a general-purpose IC can be used. Development is possible.

  Next, the operation of the rotation speed counting device 120 shown in FIG. 2 will be described. FIG. 3 is a flowchart showing an operation procedure and a rotational speed counting method of the rotational speed counting device 120 shown in FIG. 2, and FIGS. 4 and 5 are timing charts of each component of the rotational speed counting device 120 shown in FIG. It is.

  When the engine 210 rotates, the signal plate 220 also rotates. Projections are formed on the signal plate 220 at regular intervals. The rotation detection sensor 200 detects this protrusion and outputs a sinusoidal detection signal f0 as shown in FIG. The signal shaper 110 binarizes the sinusoidal detection signal f0 with a predetermined threshold value and converts it into a rotation pulse (period t1) as shown in FIGS. The clock pulse generator 122 generates clock pulses having a considerably short period as shown in FIG. In FIG. 5, tr0 and tr1 are exemplified as the rotation speed data update timing. However, when a reset signal is output from the timing control circuit 121 at this timing, the frequency measurement counter 123 and the rotation speed data counter 126 The count value is reset.

  First, as shown in FIG. 5, when a reset signal is output from the timing control circuit 121 at the rotational speed data update timing tr0, the frequency measurement counter count value is reset to zero.

  The timing control circuit 121 receives the rotation pulse a) output at a cycle according to the rotation speed of the engine 210, and waits until the rising edge (leading edge) is detected (S1: NO). When the rising edge is detected (S1: YES), the timing control circuit 121 starts supplying clock pulses to the frequency measurement counter 123. The frequency measurement counter 123 starts from the cycle of the rotation pulse from the clock pulse generator 122. Also, counting of the frequency measurement counter count value c) is started based on the clock pulse b) having a short cycle (S2). If the frequency measurement counter count value c) does not overflow (S3: NO), the counting is continued until the next rising edge of the rotation pulse a) is detected (S4: NO). When the frequency measurement counter count value c) overflows (S3: YES), or when the rising edge of the rotation pulse a) is detected (S4: YES), the supply of the clock pulse from the timing control circuit 121 is cut off to measure the frequency. The counting by the counter 123 for use is stopped (S5).

  That is, in steps S1 to S5, the frequency measurement counter 123 counts the number of clock pulses output from the clock pulse generator 122 during one period of the rotation pulse (period t1 in FIG. 5).

  Next, simultaneously with the processing of S5, the count value c) of the frequency measurement counter 123 is preset to the count value d) of the frequency dividing counter 124 (S6), and the count value e) of the conversion coefficient setting counter 124 is set to unit time. Is set to the number of clock pulses generated, for example, 12,000,000 in the above example (S7).

  Further, after waiting for the clock pulse b) (S8: NO) and detecting the clock pulse b) (S8: YES), the timing control circuit 121 sends the clock pulse b to the frequency division counter 124 and the conversion coefficient setting counter 125. ) And the subtraction of the count value d) of the frequency dividing counter 124 is started based on the clock pulse b) (S9), and at the same time, the count value e of the conversion coefficient setting counter 125 is based on the clock pulse b). ) Is started (S10).

  If the subtraction in S9 is continued, the count value d) of the frequency division counter 124 becomes 0. If the count value d) becomes 0 (S11: YES), the frequency division counter 124 issues an increment instruction, and the rotation data The value of the counter 126 is incremented by 1 (S12). Then, again, the count value c) of the frequency measurement counter 123 is preset to the count value d) of the frequency division counter 124 (S13), and is repeated until the value of the count value e) of the conversion coefficient setting counter 125 becomes zero (S13). S14: NO). That is, in the processing of S11 to S14, the number of clock pulses preset in the frequency dividing counter 124 is cumulatively subtracted from the number of clock pulses set in the conversion coefficient setting counter 125. More specifically, the number of clock pulses set in the conversion coefficient setting counter 125 and the frequency dividing counter 124 are preset based on the clock pulse generated by the clock pulse generator 122 in one subtraction process. The number of clock pulses is subtracted simultaneously until the number of clock pulses preset in the frequency dividing counter 124 becomes zero.

  When the above processing is completed, the supply of the clock pulse from the timing control circuit 121 is cut off, the count of the frequency dividing counter 124 is stopped (S15), and the count of the conversion coefficient setting counter 125 is stopped (S16). The count of the rotation data counter 126 is held. Next, the value of the 3-state register 127 is updated (S17). Therefore, the value of the 3-state register 127 itself indicates the rotation speed of the engine 120. Thereafter, the period measurement counter 123 is reset for measurement of the next rotation pulse (S18), and the timing control circuit 121 is initialized (S19). This counts how many times the time measured by the period measuring counter 123 falls within a unit time (for example, 60 seconds) set in the frequency dividing counter 124.

  Therefore, since the number of subtractions simply indicates the rotational speed (rpm) of the engine 210, the rotational speed of the engine 210 can be counted simply by performing increment / subtraction processing of a plurality of counters.

Even if the clock pulse generator 122 cannot set the exact clock frequency as designed, if the clock pulse generation period is sufficiently smaller than the rotation pulse generation period t1, the conversion coefficient setting counter 125 is used. By correcting the number of clock pulses set to, the measurement error of the rotational speed becomes negligible.
[Embodiment 2]
FIG. 6 is a block diagram showing the configuration of the rotational speed counter of the rotating body according to Embodiment 2 of the present invention. In this figure, the same members as those in the rotational speed counting device 120 in FIG. Elements to which the same reference numerals are attached operate in the same manner as the elements shown in the first embodiment. Therefore, the description of the elements having the same action is omitted here.

  As described above, the rotational speed counter 120 of the rotating body according to the first embodiment can also obtain an accurate rotational speed in a wide rotational speed region without imposing a calculation burden on the computer 130. However, in the first embodiment, tr0 is adopted as the rotation speed data update timing (see FIG. 5), which is much longer than the measurement period t1 (rotation pulse generation timing), and therefore more accurate measurement values. There are some problems when trying to get In this embodiment, in order to solve this problem, a high-speed clock pulse having a cycle (one-multiple: in other words, multiple times the frequency) considerably shorter than that of the first embodiment may be generated as a clock pulse. A high-speed clock pulse generator 122A capable of performing the subtraction of the count values in the frequency division counter 124 and the conversion coefficient setting counter 125 can be performed in a short time with this high-speed pulse. As the clock pulse speed increases, a clock pulse that functions as a clock pulse frequency dividing means is generated between the high-speed clock pulse generator 122A and the timing circuit 121 in order to generate a frequency-divided clock that increments the period measurement counter 123. A frequency divider circuit 129 is provided. Further, with the increase in the speed of the clock pulse, the timing circuit 121 can be processed based on the high-speed clock pulse in order to ensure the storage time of data in each counter and register. Thus, all the processes can be completed within the generation timing t1 of the rotation pulse. Further, a latch unit 128 for temporarily storing the count value is provided between the frequency setting counter 123 and the frequency dividing counter 124 so that the rotation data can be updated for each rotation pulse.

  The difference from the first embodiment in the configuration of the rotation speed counting device 120A is as described above. Next, the operation of the rotational speed counting device 120A shown in FIG. 6 according to the present embodiment will be described based on FIGS. 3 to 5 as in the first embodiment. Note that a clock pulse with a very high frequency is output from the high-speed clock pulse generator 122A. The high-speed clock pulse is frequency-divided by the clock pulse frequency dividing circuit 129, and the clock pulse after frequency division and the high-speed clock pulse before frequency division are output to the timing control circuit 121. The high-speed clock pulse is used when the count values of the frequency division counter 124 and the conversion coefficient setting counter 125 are subtracted. This is because the time required for subtraction can be shortened by subtracting with the high-speed clock pulse.

  First, as shown in FIG. 5, when a reset signal is output at the rotation speed data update timing tr0, the frequency measurement counter count value is reset to zero.

  The timing control circuit 121 receives the rotation pulse a) output at a cycle according to the rotation speed of the engine 210, and waits until the rising edge (leading edge) is detected (S1: NO). When the rising edge is detected (S1: YES), the timing control circuit 121 outputs an increment command to the frequency measurement counter 123, and the frequency measurement counter 123 outputs the divided clock from the high-speed clock pulse generator 122. Based on the pulse b), counting of the frequency measurement counter count value c) is started (S2). If the frequency measurement counter count value c) does not overflow (S3: NO), the count is continued until the rising edge of the rotation pulse a) is detected (S4: NO). When the frequency measurement counter count value c) overflows (S3: YES) or when the rising edge of the rotation pulse a) is detected (S4: YES), the frequency measurement counter 123 stops counting (S5).

  That is, in steps S1 to S5, the frequency measurement counter 123 counts the number of frequency-divided clock pulses output from the clock pulse frequency dividing circuit 129 during one rotation pulse period (period t1 in FIG. 5). Will do.

  Next, almost simultaneously with the processing of S5, the count value c) of the frequency measurement counter 123 is temporarily stored in the latch unit 128, and once reset, the counting is started again based on the instruction of the timing control circuit 121. . This is preset to the count value d) of the frequency division counter 124 (S6), and the count value e) of the conversion coefficient setting counter 125 is set to the number of frequency-divided clock pulses generated within a unit time, for example, the above example In other words, it is set to 1200000 (S7).

  Further, after waiting for the input of the high-speed pulse (S8: NO), when the input of the high-speed pulse is detected (S8: YES), the timing control circuit 121 determines the frequency division counter 124 based on the high-speed clock pulse b). (S9), the subtraction of the count value e) of the conversion coefficient setting counter 125 is started based on the high-speed clock pulse b) (S10).

  If the subtraction in S9 is continued, the count value d) of the frequency division counter 124 becomes 0. If the count value d) becomes 0 (S11: YES), the frequency division counter 124 issues an increment instruction, and the rotation data The value of the counter 126 is incremented by 1 (S12). Again, the count value c) of the frequency measurement counter 123 is preset to the count value d) of the frequency division counter 124 (S13), and the subtraction is performed until the count value e) of the conversion coefficient setting counter 125 becomes zero. The process is repeated (S14: NO). In other words, in the processing of S11 to S14, the number of clock pulses latched in the frequency division counter 124 from the number of frequency-divided clock pulses set in the conversion coefficient setting counter 125 is accumulated, and the high-speed clock pulse is accumulated. Subtracting using is performed. More specifically, the number of clock pulses set in the conversion coefficient setting counter 125 and the frequency dividing counter 124 based on the high-speed clock pulse generated by the high-speed clock pulse generator 122A in one subtraction process. The number of clock pulses latched is simultaneously subtracted until the number of clock pulses latched in the frequency division counter 124 becomes zero.

  When the above processing is completed, the count of the frequency dividing counter 124 is stopped (S15), the count of the conversion coefficient setting counter 125 is stopped (S16), and the value of the 3-state register 127 is updated (S17). Therefore, the value of the 3-state register 127 itself indicates the rotation speed of the engine 120.

  Thus, in this embodiment, since the count number is subtracted using the high-speed clock pulse, the processing time can be greatly shortened and is close to the resolution of the rotation detection sensor (one rotation pulse period). It is also possible to detect the rotational speed within the time. Therefore, the rotational speed of the engine can be detected almost in real time, and the engine can be finely controlled.

  Since the present invention can measure the rotational speed of a rotating body over a wide range and with high accuracy, it can be used for an apparatus for measuring the rotational speed of an engine or motor, for example.

It is a schematic block diagram of the rotary body control apparatus which concerns on this invention. It is a block diagram which shows the structure of the rotational speed counting apparatus which concerns on this invention. It is a flowchart which shows the operation | movement procedure and rotational speed counting method of the rotational speed counting apparatus shown in FIG. It is a timing chart of each component of the rotational speed counting device shown in FIG. It is a timing chart of each component of the rotational speed counting device shown in FIG. It is a schematic block diagram of the other rotary body control apparatus which concerns on this invention.

Explanation of symbols

100 engine control device,
110 signal shaper,
120, 120A rotational speed counting device,
121 timing control circuit,
122 clock pulse generator,
122A high-speed clock pulse generator,
123 counter for period measurement,
124 divider counter,
125 Counter for setting conversion coefficient,
126 rotation speed data counter,
127 3-state register,
128 latch part,
129 clock pulse frequency divider,
130 computers,
140 data bus lines,
200 rotation detection sensor,
210 engine,
220 Signal plate.

Claims (10)

Rotation pulse input means for inputting a rotation pulse output at a cycle according to the rotation speed of the rotating body;
A clock pulse generator for generating a clock pulse with a cycle shorter than the cycle of the rotation pulse;
A period measuring counter that counts the number of clock pulses generated during one period of the rotation pulse;
A frequency division counter that latches the number of clock pulses counted by the period measurement counter;
A conversion coefficient setting counter for setting the number of clock pulses generated within a unit time from the clock pulse generator;
Subtracting means for cumulatively subtracting the number of clock pulses latched in the frequency dividing counter from the number of clock pulses set in the conversion coefficient setting counter;
Counting means for counting the number of subtractions performed by the subtracting means within the unit time and counting the rotational speed of the rotating body from the counted number;
A rotating speed counting device for a rotating body, comprising: Rotation pulse input means for inputting a rotation pulse output at a cycle according to the rotation speed of the rotating body;
A high-speed clock pulse generator for generating a high-speed clock pulse having a frequency that is a multiple of the frequency of the clock pulse generated by the clock pulse generator according to claim 1;
Clock pulse dividing means for dividing the high-speed clock pulse;
A period measurement counter that counts the number of frequency-divided clock pulses generated during one period of the rotation pulse;
A latch unit that temporarily stores the number of clock pulses counted by the period measurement counter;
A frequency dividing counter for latching the number of clock pulses stored in the latch unit;
A conversion coefficient setting counter for setting the number of clock pulses after frequency division of the high-speed clock pulse generated within a unit time from the high-speed clock pulse generator;
Based on the high-speed clock pulse generated by the high-speed clock pulse generator, the number of clock pulses latched in the frequency division counter is cumulatively subtracted from the number of clock pulses set in the conversion coefficient setting counter. Subtracting means to
Counting means for counting the number of subtractions performed by the subtracting means within the unit time and counting the rotational speed of the rotating body from the counted number;
A rotating speed counting device for a rotating body, comprising:   The rotation speed counting device according to claim 1 or 2 is connected between a rotation pulse detecting means for generating a rotation pulse at a cycle corresponding to the rotation speed of the rotating body and a computer for controlling the rotating body. A rotating body control device.   3. The rotational speed counting according to claim 1, wherein the period measuring counter, the frequency dividing counter, the conversion coefficient setting counter, and the counting means are all configured using only a counter having a predetermined number of bits. apparatus.   The number of bits required for the period measurement counter, the frequency division counter, the conversion coefficient setting counter, and the counting means is determined based on the measurement range of the rotational speed of the rotating body and the required measurement accuracy. The rotation speed counting device according to claim 1 or 2, characterized in that.   The rotation speed counting apparatus according to claim 1 or 2, wherein the unit time is 60 seconds.   The subtracting means is latched in the frequency dividing counter and the number of clock pulses set in the conversion coefficient setting counter based on the clock pulse generated by the clock pulse generator in one subtraction. 2. The rotational speed counting apparatus according to claim 1, wherein the number of clock pulses is subtracted simultaneously until the number of clock pulses latched in the frequency dividing counter becomes zero.   The subtracting means is latched by the frequency dividing counter and the number of clock pulses set in the conversion coefficient setting counter based on the high speed clock pulse generated by the high speed clock pulse generator in one subtraction. 3. The rotational speed counting device according to claim 2, wherein the number of clock pulses being subtracted is simultaneously subtracted from the number of clock pulses latched in the frequency dividing counter until the number of clock pulses latched to zero. A step of inputting a rotation pulse output at a cycle according to the rotation speed of the rotating body;
Generating a clock pulse with a period shorter than the period of the rotation pulse;
Counting the number of clock pulses generated during one period of the rotation pulse;
Latching the counted number of clock pulses;
Setting the number of clock pulses generated within a unit time; and
A step of cumulatively subtracting the number of clock pulses latched from the number of clock pulses set each time the rotation pulse is input (timing control circuit)
A step of counting the number of subtractions performed within a unit time and counting the rotational speed of the rotating body from the counted number, (rotation number data counter, 3-state register)
A method of counting the rotational speed of a rotating body. A step of inputting a rotation pulse output at a cycle according to the rotation speed of the rotating body;
Generating a high-speed clock pulse having a frequency that is a multiple of the frequency of the clock pulse of claim 9;
Dividing the high-speed clock pulse;
Counting the number of divided clock pulses generated during one period of the rotation pulse;
Temporarily storing the counted number of clock pulses;
Latching the number of temporarily stored clock pulses;
Setting the number of clock pulses after dividing the high-speed clock pulse generated within a unit time; and
Cumulatively subtracting the number of latched clock pulses from the set number of clock pulses based on the fast clock pulses;
Counting the number of subtractions performed within a unit time and counting the rotational speed of the rotating body from the counted number;
A method of counting the rotational speed of a rotating body.

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