JP2012233736A - Rotational speed calculating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a rotational speed calculating device capable of reducing an interruption load on a CPU at a high speed rotation without imposing a new cost up to an independent rotary shaft.SOLUTION: Rotational speed operating means 31-33 includes an interruption processing section 71 that processes an interruption of a pulse input; a pulse input interruption processing permit/prohibit switch 72 that permits/prohibits the interruption processing in the interruption processing section 71; and a rotational speed operating section 68 that operates the rotational speed using the pulse input processed by the interruption processing section 71. The interruption processing section 71 includes a pulse count processing section 65 that counts the input pulses; a time measuring section 60 that measures the time of an input pulse; and a time storing processing section 70 that stores the time measured by the time measuring section 60. When the number of the pulses counted by the pulse count processing section 65 is a predetermined value or more in a predetermined time, the interruption processing by the interruption processing section 71 is prohibited.

Description

  The present invention relates to a rotation speed calculation device for calculating the rotation speed of an automobile engine, transmission, or the like.

  Conventionally, as a method for calculating the rotational speed of an engine or transmission for an automobile, for example, as disclosed in Japanese Patent Application Laid-Open No. 5-203657 (Patent Document 1), the frequency of the arithmetic processing is divided according to the frequency of the input signal. For example, as disclosed in Japanese Patent Application Laid-Open No. 9-329623 (Patent Document 2), there is one that switches the number of pulses to be counted in at least two stages according to the vehicle speed.

  Further, as disclosed in, for example, Japanese Patent Application Laid-Open No. 9-236174 (Patent Document 3), in the state where the lockup clutch ON signal is output in the automatic transmission, the transmission from the input rotational speed sensor of the transmission. Some input signals are processed as engine speed.

  Furthermore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 2003-194840 (Patent Document 4), a period calculation for counting the time when the pulse number of the pulse signal corresponding to the moving speed reaches the reference pulse number, and a reference measurement time Among them, a pulse count calculation for counting the number of pulses of the pulse signal is performed in parallel, and for example, as disclosed in Japanese Patent Application Laid-Open No. 2008-76293 (Patent Document 5), There are those that switch between two timer counters for low speed and high speed depending on the speed.

Japanese Patent Laid-Open No. 5-203657 (translation column, FIG. 1) Japanese Patent Laid-Open No. 9-329623 (translation column, FIG. 2) Japanese Patent Laid-Open No. 9-236174 (translation column, FIG. 4) JP 2003-194840 A (translation column, FIG. 1) JP 2008-76293 A (translation column, FIG. 1)

  The rotational speed of a gear provided in an automobile engine, transmission, or the like is calculated from the number and period of pulses of an input pulse signal. The number of pulses (for calculating the period) and the input time are processed because the interrupt function of the CPU built in the control computer is used, so that the pulses input per unit time as the rotational speed increases. There is a problem that the number of interrupts increases as the number of signals increases, increasing the load on the CPU.

  In particular, when controlling an engine and a transmission, information on the rotational speed is very important basic information, and therefore, accuracy of the information is always required. For this reason, pulse signal input interrupts have a higher priority than other interrupt processes and tasks, and are normally set to the highest priority, so the interrupt processing load due to the increase in rotation speed is directly linked to the CPU load. To do.

  Thus, the technique disclosed in Patent Document 1 can be considered. However, the disclosed technique disclosed in Patent Document 1 requires a new frequency discriminating circuit, which increases the cost accordingly.

  Although the method disclosed in Patent Document 2 is also conceivable, since the disclosed technique of Patent Document 2 does not limit the number of pulses, the number of pulse input interruptions per unit time does not change, and the rotational speed is the same. There is a problem that the interrupt load increases as the size increases.

  Although the method disclosed in Patent Document 3 can be considered, the disclosed technique disclosed in Patent Document 3 may be a system-related value such as the relationship between the engine rotational speed and the transmission input rotational speed. However, there is a problem that this method cannot be applied to values that are systemically independent.

  Furthermore, although the method disclosed in Patent Document 4 can be considered, since the technique disclosed in Patent Document 4 processes two systems in parallel, there is a problem that the CPU load increases due to interrupt processing and arithmetic processing. is there. In particular, when calculating the rotational speed for automobile control as in the present technical field, usually, a single microcomputer is in charge of various controls, and it is desired to make each calculation process as small as possible. It is necessary to reduce the CPU load as much as possible. For this reason, the method disclosed in Patent Document 4 is not suitable for calculating the rotational speed for automobiles.

  Although the technique disclosed in Patent Document 5 is also conceivable, the disclosed technique of Patent Document 5 does not limit the pulse input interrupt itself only by switching the timer. Therefore, as the rotational speed increases, the CPU There is a problem that the interrupt load increases.

  The present invention has been made in view of the above-described problems, and is capable of reducing the interruption load applied to the CPU at a high rotational speed without incurring a new cost for a rotationally independent rotating shaft. The object is to obtain a speed calculation device.

  A rotational speed calculation device according to the present invention is a rotational speed calculation device for calculating a rotational speed of a gear provided in an engine or a transmission, wherein the rotational speed calculation means calculates the rotational speed by pulse input from a rotation sensor. The rotation speed calculation means includes: an interrupt processing unit that processes the pulse input interrupt; and a pulse input interrupt processing permission / inhibition unit that permits / inhibits interrupt processing in the interrupt processing unit. And a rotation speed calculation processing unit that calculates a rotation speed by the pulse input processed by the interrupt processing unit. The interrupt processing unit includes a pulse count processing unit that counts the input pulses, and the input pulse. A time measurement processing unit for measuring the input time of the time, and a time storage process for storing the time measured by the time measurement processing unit With the door, when the number of pulses counted by the pulse counting section exceeds a predetermined value at predetermined time intervals, it is to disable the interrupt process in the interrupt processing unit.

  According to the rotational speed calculation device of the present invention, even a CPU with low processing capability can provide the same calculation result as a CPU with high processing capability, so that a control computer can be configured with an inexpensive CPU, thereby reducing costs. Can be realized.

1 is a system configuration diagram of an automobile to which a rotation speed calculation device according to Embodiment 1 is applied. 1 is a block diagram illustrating a rotation speed calculation device according to a first embodiment. FIG. 3 is a functional block diagram illustrating a rotation speed calculation device according to the first embodiment. It is an interruption process time chart of the conventional rotational speed calculation apparatus. It is a rotational speed calculation flowchart of the conventional rotational speed calculation apparatus. It is a functional block diagram explaining the rotational speed calculation method of the conventional rotational speed calculation apparatus. It is a RAM value transition diagram of the conventional rotational speed calculation device. 3 is an interrupt processing time chart of the rotation speed calculation device according to the first embodiment. 4 is a rotation speed calculation flowchart of the rotation speed calculation apparatus according to the first embodiment. 3 is a functional block diagram for explaining a rotational speed calculation method of the rotational speed calculation apparatus according to Embodiment 1. FIG. FIG. 3 is a RAM value transition diagram of the rotation speed calculation device according to the first embodiment. 10 is a time chart of a plurality of rotation axes in the rotation speed calculation device according to the second embodiment.

  Preferred embodiments of a rotational speed calculation apparatus according to the present invention will be described below with reference to the accompanying drawings. Note that the present invention is not limited to this embodiment, and includes various design changes.

Embodiment 1 FIG.
FIG. 1 is a system configuration diagram of an automobile to which a rotational speed calculation device according to Embodiment 1 of the present invention is applied. The automobile 100 includes an engine 1, a transmission (hereinafter referred to as CVT) 2, and a CVT control computer (hereinafter referred to as TCU) 3 that controls the CVT 2. The power of the engine 1 drives the oil pump 4 and is input to the input shaft 6 of the CVT 2 via the clutch 5 to rotate the primary pulley 7 and the secondary pulley 8. Note that the transmission mechanism of the primary pulley 7 or the secondary pulley 8 is operated by hydraulic pressure and changes the transmission ratio.

  The input shaft 6 of the CVT 2 has a first gear 9, and a first rotation sensor 10 is provided facing the first gear 9. The secondary pulley 8 is provided with an output shaft 11 of the CVT 2, the output shaft 11 has a second gear 12, and a second rotation sensor 13 is provided facing the second gear 12. Yes.

  The input of the TCU 3 includes the rotation signal from the first rotation sensor 10 or the second rotation sensor 13, the range signal from the range selector 14, the accelerator opening signal from the accelerator 15, the oil pressure of each part, the oil temperature, etc. is there. The output of the TCU 3 includes a first solenoid 16 for hydraulic control that operates the transmission mechanism of the primary pulley 7, a second solenoid 17 for hydraulic control that operates the transmission mechanism of the secondary pulley 8, and other components. There are electrical signals for driving the third and fourth solenoids 18 and 19 for controlling the hydraulic pressure of the oil pumps. By driving the solenoids 16, 17, 18 and 19 with the electrical signals, the oil pump 4 Of the generated hydraulic pressure, the gear ratio and the like are controlled by adjusting the hydraulic pressure applied to each part.

  In addition, the code | symbol Y1-Y5 in a figure has shown the hydraulic circuit. The CVT 2 includes an oil pump 4, a clutch 5, an input shaft 6, a primary pulley 7, a secondary pulley 8, a first gear 9, a first rotation sensor 10, an output shaft 11, a second gear 12, and a second rotation. A sensor 13 is provided.

Next, the configuration of the TCU 3 will be described with reference to FIG.
The TCU 3 includes a CPU 20, a ROM 21, a RAM 22, and an oscillator 23. Various signals described with reference to FIG. The ROM 21 stores logic and data for controlling the CVT 3, and the RAM 22 stores variables and the like for controlling the CVT 3. Further, the CPU 20 operates the logic in the ROM 21 at a preset cycle based on the information of the oscillator 23, or accesses the RAM 22 to read / write variables in the RAM 22. CPU20 calculates and outputs the drive signal of each solenoid 16-19 (refer FIG. 1) from various input information.

Next, the functional configuration of the TCU 3 will be described with reference to FIG.
The TCU 3 includes the following means. That is, a 10 ms timing generation means 30 for generating a reference period of control, a primary rotation speed calculation means 31 for calculating the rotation speed of the primary pulley 7, a secondary rotation speed calculation means 32 for calculating the rotation speed of the secondary pulley 8, A vehicle speed calculation means 33 for calculating the speed of the vehicle body from a tire shaft and the like, and an accelerator opening degree calculation means 34 for calculating the amount of depression of the accelerator 15 are further provided. Further, the current gear ratio is calculated from the primary rotation speed and the secondary rotation speed. Current gear ratio calculating means 35, target gear ratio calculating means 36 for calculating the gear ratio targeted by the driver from the vehicle speed and the accelerator opening, and gear ratio deviation for calculating the deviation between the current gear ratio and the target gear ratio. The calculation means 37 and the gear ratio deviation should be applied to the primary pulley 7, the secondary pulley 8, etc. A target pressure calculating means 38 for calculating a hydraulic pressure, and a solenoid drive signal computing means 39 for calculating a drive signal output to the first to fourth solenoid 16 to 19 so that the target hydraulic pressure.

  Each rotation pulse signal of primary, secondary, and vehicle speed is input to each calculation means 31, 32, and 33, and each rotation speed is calculated every 10 ms. The accelerator opening signal is input to the accelerator opening calculating means 34, and the amount of depression of the accelerator 15, which is the driver's intention to accelerate, is calculated.

The primary and secondary rotation speeds calculated by the primary rotation speed calculation means 31 and the secondary rotation speed calculation means 32 are input to the current gear ratio calculation means 35, and the current gear ratio is calculated according to the following equation 1.
Current gear ratio = secondary rotational speed / primary rotational speed Equation 1

  Further, the vehicle speed calculated by the vehicle speed calculating means 33 and the accelerator opening calculated by the accelerator opening calculating means 34 are input to the target gear ratio calculating means 36 and set in advance with the vehicle speed and the accelerator opening as axes. The target gear ratio is calculated based on the map value.

  The current gear ratio calculated by the current gear ratio calculating means 35 and the target gear ratio calculated by the target gear ratio calculating means 36 are input to the gear ratio deviation calculating means 37, and the deviation between the current gear ratio and the target gear ratio is calculated. Calculated. The gear ratio deviation calculated by the gear ratio deviation calculating means 37 is input to the target hydraulic pressure calculating means 38, and the target hydraulic pressure of each part is calculated from the gear ratio deviation. The target hydraulic pressure calculated by the target hydraulic pressure calculation means 38 is input to the solenoid drive signal calculation means 39, and a solenoid drive signal is calculated from the target hydraulic pressure for each part to drive the first to fourth solenoids 16-19. To do.

  When the first to fourth solenoids 16 to 19 are driven, hydraulic pressure is applied to each part in the CVT 2, and the primary pulley 7 and the secondary pulley 8 are controlled. As a result, each rotational speed and the like change, It becomes a new input signal of CVT2.

  Next, a rotational speed calculation method by the rotational speed calculation device according to Embodiment 1 will be described in comparison with a conventional rotational speed calculation method.

First, a conventional rotational speed calculation method will be described with reference to FIGS. 4 is an interrupt processing time chart, FIG. 5 is a rotational speed calculation flowchart, FIG. 6 is a functional block diagram for explaining the rotational speed calculation method, and FIG. 7 is a RAM value transition diagram.
In the conventional rotational speed calculation method, when the gear 9 provided on the input shaft 6 of the primary pulley 7 in the CVT 2 and the gear 12 provided on the output shaft 11 of the secondary pulley 8 rotate,
A magnetic field is generated in the rotation sensors 10 and 13 provided to face the gears 9 and 12, and the voltage varies according to the passage of the gears 9 and 12. In the TCU 2, this voltage fluctuation is converted into a rectangular wave as shown at the top of FIG. 4 and input to the CPU 20. In the CPU 20, for example, a rising edge of the rectangular wave is interrupted as a pulse input, and used for calculation of the rotational speed described below.

  On the other hand, the oscillator 23 continues to output a signal having a predetermined frequency, and the 10 ms timing generation unit 30 generates, for example, a 10 ms signal which is a control reference period (hereinafter referred to as main processing).

  Next, pulse input interrupt processing will be described with reference to the flowchart of FIG. 5 and the functional block diagram of FIG. As shown in the flowchart of FIG. 5A, if there is a pulse input interruption, it is determined whether or not the input is the first pulse input after the main period (step 1a).

  If the input interrupt is the first pulse input in step 1a, the process proceeds to step 2a, the time is measured by the time measurement processing unit 60, and the time is set as Tnew in the first storage unit 61 and Told in the second storage unit 62. Is stored. Thereafter, the process proceeds to step 3a, where the initial pulse input flag 64 is turned OFF by the initial pulse input information unit 63 (see point a in FIG. 4), the pulse count is reset to 0 by the pulse count processing unit 65, and the pulse counter 66 is reset to Pcount. Store as.

  Whether or not the pulse input in step 1a is the first pulse input after the main period is determined by the first pulse input information unit 63. The initial pulse input information unit 63 determines whether or not the pulse input is the first time based on the ON / OFF state of the initial pulse input flag 64. That is, when the initial pulse input flag 64 is ON, it is determined as the initial pulse, and when it is OFF, it is determined that it is not the initial pulse. When a pulse is input with the initial pulse input flag 64 being ON at the timing of the main cycle (10 ms) by the 10 ms timing generation means 30, the input is determined to be the initial pulse after the main cycle, and the second After updating Told in the storage unit 62, the initial pulse input flag 64 is turned off. If there is a next pulse input within the main period, the initial pulse input flag 64 is OFF, and the initial pulse input information unit 63 determines that it is not the initial pulse.

  Subsequently, if there is a second pulse input interrupt in the main process, since the initial pulse input flag 64 has already been turned off in step 1a, the process proceeds to step 4a. The Tnew value stored in the storage unit 61 of 1 is overwritten, and then the process proceeds to step 5a, where 1 is added to Pcount stored in the pulse counter 66 by the pulse count processing unit 65, and the number of added pulses Is stored in the pulse counter 66 (see point b in FIG. 4).

  Subsequently, if there is a third pulse input interrupt in the main process, as in the second time, since the initial pulse input flag 64 has already been turned off in step 1a, the process proceeds to step 4a, where the time measurement processing unit 60 The time is measured and overwritten to the value of Tnew stored in the first storage unit 61. Then, the process proceeds to step 5a, and the pulse count processing unit 65 adds 1 to Pcount stored in the pulse counter 66. The number of added pulses is stored in the pulse counter 66 (see point c in FIG. 4).

As described above, for example, when there are eight pulse input interruptions in the main processing, Pcount of the pulse counter 66, Told stored in the second storage unit 62, and stored in the first storage unit 61 are stored. Tnew that is in transition as shown in the table of FIG. That is, at the time when the eighth pulse input interrupt ends, pulse count = 7, first pulse input time = T0,
Latest (8th) pulse input time = T7.

Next, the main process will be described with reference to FIG. At the timing of the main process generated by the 10 ms timing generating means 30, the pulse counter 66 is turned on only once by turning on the rotation speed calculation process permission / prohibition switch 67, which is the rotation speed calculation process permission / prohibition means, in step 1b. The stored Pcount, the Tnew stored in the first storage unit 61, and the value of Told stored in the second storage unit 62 are input to the rotational speed calculation processing unit 68, and rotated according to the following equation 2. Calculate the speed.
Rotational speed (rpm) = (pulse count / number of teeth) / (Tnew-Told) Equation 2

  Subsequently, the process proceeds to step 2b, where the initial pulse input flag 64 is turned on in the initial pulse input information section 63 (see point A in FIG. 4), and the process proceeds to step 3b, where the pulse count processing section 69 causes the pulse counter 66 to count the pulse. Reset to -1 (see point B in FIG. 4).

  The above is a series of processing of the conventional rotational speed calculation method and the pulse count Pcount, initial pulse input time Told, and latest pulse input time Tnew used for the rotational speed calculation. In FIG. 6, the first storage unit 61, the second storage unit 62, and the initial pulse input flag 64 constitute a time storage processing unit 70, and a time measurement processing unit 60, a pulse count processing unit 65, and a time storage process The interrupt processing unit 71 is configured by the unit 70.

Next, the rotational speed calculation method according to the first embodiment will be described with reference to FIGS. 8 is an interrupt processing time chart, FIG. 9 is a rotational speed calculation flowchart, FIG. 10 is a functional block diagram for explaining the rotational speed calculation method, and FIG. 11 is a RAM value transition diagram.
In the rotational speed calculation method according to the first embodiment, when the gear 9 provided on the input shaft 6 of the primary pulley 7 in the CVT 2 and the gear 12 provided on the output shaft 11 of the secondary pulley 8 rotate, the gear 9 , 12 generates a magnetic field in the rotation sensors 10, 13 provided opposite to the rotation sensors 10, 12, and the voltage fluctuates in accordance with the passage of the gears 9, 12. The TCU 2 converts this voltage fluctuation into a rectangular wave as shown at the top of FIG. 8 and inputs it to the CPU 20. In the CPU 20, for example, a rising edge of the rectangular wave is interrupted as a pulse input, and used for calculation of the rotational speed described below.

  On the other hand, the oscillator 23 continues to output a signal having a predetermined frequency, and the 10 ms timing generation unit 30 generates a reference period of control, that is, a 10 ms signal that is a main process.

  Next, the pulse input interrupt processing will be described with reference to the flowchart of FIG. 9 and the functional block diagram of FIG. As shown in the flowchart of FIG. 9, if there is a pulse input interrupt, it is determined whether or not the input is the first pulse input after the main period (step 1a).

  If the input interrupt is the first pulse input in step 1a, the process proceeds to step 2a, the time is measured by the time measurement processing unit 60, and the time is set as Tnew in the first storage unit 61 and Told in the second storage unit 62. Is stored. Thereafter, the process proceeds to step 3a, where the initial pulse input flag 64 is turned OFF by the initial pulse input information unit 63 (see point a in FIG. 8), the pulse count is reset to 0 by the pulse count processing unit 65, and the pulse counter 66 is reset to Pcount. Store as. Whether the pulse input is the first pulse input after the main period is determined by the first pulse input information unit 63 as described above.

Subsequently, if there is a second pulse input interrupt in the main process, since the initial pulse input flag 64 has already been turned off in step 1a, the process proceeds to step 4a. The Tnew value stored in the storage unit 61 of 1 is overwritten, and then the process proceeds to step 5a, where 1 is added to Pcount stored in the pulse counter 66 by the pulse count processing unit 65, and the number of added pulses Is stored in the pulse counter 66 (see point b in FIG. 8).

  Subsequently, if there is a third pulse input interrupt in the main process, as in the second time, since the initial pulse input flag 64 has already been turned off in step 1a, the process proceeds to step 4a, where the time measurement processing unit 60 The time is measured and overwritten to the value of Tnew stored in the first storage unit 61. Then, the process proceeds to step 5a, and the pulse count processing unit 65 adds 1 to Pcount stored in the pulse counter 66. The added number of pulses is stored in the pulse counter 66. (See point c in FIG. 8). The steps so far are the same as the conventional calculation method described above.

  Next, the process proceeds to step 6a, where it is determined whether or not the pulse count Pcount stored in the pulse counter 66 is greater than or equal to a predetermined value. If the pulse count Pcount is greater than or equal to a predetermined value (for example, 5), the process proceeds to step 7a. The pulse input interrupt process permission / prohibition switch 72, which is a prohibition means, is turned OFF (see point C in FIG. 8).

  When the pulse input interrupt processing enable / disable switch 72 disables the pulse input interrupt as described above, the interrupt processing cannot be performed even if a pulse is input thereafter, so the pulse count Pcount, The initial pulse input time Told of the second storage unit 62 and the latest pulse input time Tnew of the first storage unit 61 are as shown by points f to h in FIG. 8, and the values are the values of f to h in FIG. Thus, it is not updated from Pcount = 5, Told = T0, and Tnew = T5.

Next, the main process will be described with reference to FIG. At the timing of the main process generated by the 10 ms timing generating unit 30, the Pcount stored in the pulse counter 66 and the first storage are turned on by turning ON the rotation speed calculation process permission / prohibition switch 67 only once in step 1b. The value of Tnew stored in the unit 61 and the value of Told stored in the second storage unit 62 are input to the rotation speed calculation processing unit 68, and the rotation speed is calculated according to the following equation 3.
Rotation speed [rpm] = (pulse count / number of teeth) / (Tnew-Told) Equation 3

  Subsequently, the process proceeds to step 2b, where the initial pulse input flag 64 is turned ON in the initial pulse input information unit 63 (see point A in FIG. 8), and the process proceeds to step 3b, where the pulse count processing unit 69 sets the pulse count of the pulse counter 66. Reset to -1 (see point B in FIG. 8). The steps so far are the same as the conventional calculation method described above.

  Next, proceeding to step 4b, the pulse input interrupt processing enable / disable switch 72 is turned ON to prepare for a pulse input interrupt in the next main cycle again.

  That is, when the interrupt limit count is set to 5 as described above, interrupt processing is prohibited after point e in FIG. 8, and therefore interrupt processing is not performed even if there is a pulse input at points f to h in FIG. , The rotation speed is calculated with the pulse count = 5 with respect to the time T0 to T5. In FIG. 10, a time measurement processing unit 60 and a pulse count processing unit 65 constitute an interrupt processing unit 71, and a time storage processing unit is constituted by a first storage unit 61, a second storage unit 62, and an initial pulse input flag 64. 70 is configured.

  As described above, when the rotational speed calculation method by the rotational speed calculation apparatus according to the first embodiment is used, the interrupt input process is not performed more than the preset number of times during one main process, and therefore, a pulse per main process time. The load of interrupt processing due to input is limited. Therefore, the interrupt load of the CPU does not increase, and even a CPU with a low processing capability can provide the same calculation result as a CPU with a high processing capability. Therefore, it becomes possible to configure a control computer with an inexpensive CPU, thereby reducing costs. realizable.

Embodiment 2. FIG.
Next, the rotational speed calculation apparatus according to the second embodiment will be described with reference to FIGS. 8, 9, 11, and 12.
The engine, or particularly the CVT, has a plurality of rotating shafts, each of which has a different rotational speed range and number of teeth in normal use. For example, as shown in FIG. 12 (a), when the number of teeth on axis A and axis B is n and 2n, respectively, the pulse count input to one main process when axis A and axis B are set to the same rotational speed Is twice the axis A (2n / n). At this time, if the interrupt limit count of axis A is the same as that of axis B, interrupt processing is prohibited for axis B after pulse count = 5. The calculation accuracy will deteriorate. Therefore, in order to achieve the same calculation accuracy as that of the axis A, the interrupt limit number is set according to the following expression 4.
Interrupt set count = p × m / n × t / s Equation 4
p: Reference limit value for interrupt limit count n: Number of teeth on the reference rotation axis m: Number of teeth on the target rotation axis s: Maximum rotation speed for the reference rotation axis t: Maximum rotation speed for the target rotation axis

  If the pulse count Pcount of the pulse counter 66 is equal to or larger than the interrupt set number obtained by the equation 4, the process proceeds to step 7a in FIG. 9 and the pulse input interrupt process enable / disable switch 72 is turned OFF (see point C in FIG. 8).

  If the pulse input interrupt processing enable / disable switch 72 prohibits pulse input interrupts, interrupt processing cannot be performed even if a pulse is input thereafter, so the pulse count Pcount of the pulse counter 66, the second storage unit The first pulse input time Told stored in 62 and the latest pulse input time Tnew stored in the first storage unit 61 are as shown by points f to h in FIG. 8, and the values are f in FIG. It is not updated from Pcount = 5, Told = T0, and Tnew = T5 as in ~ h.

  Even at the main processing timing, the pulse count processing in the pulse count processing unit 69 in step 3b of FIG. Thereafter, the process proceeds to step 4b, where the pulse input interrupt processing enable / disable switch 72 is turned ON to prepare for a pulse input interrupt in the next main cycle again.

  In other words, when the interrupt limit count is set to the value obtained by Equation 4 as described above, the interrupt prohibition time is shortened depending on the number of teeth and the maximum use range rotation speed, as shown in FIGS. 12 (a) and 12 (b). Therefore, even if the number of teeth and the maximum rotation speed are large, the rotation speed is calculated by limiting interruption processing in one main while maintaining a constant calculation accuracy.

1 Engine 2 Transmission (CVT)
3 CVT control computer (TCU) 4 Oil pump 5 Clutch 6 Input shaft 7 Primary pulley 8 Secondary pulley 9 First gear 10 First rotation sensor 11 Output shaft 12 Second gear 13 Second rotation sensor 14 Range selector 15 Accelerator 16 First solenoid 17 Second solenoid 18 Third solenoid 19 Fourth solenoid 20 CPU
21 ROM 22 RAM
23 oscillator 30 10 ms timing generation means 31 primary rotation speed calculation means 32 secondary rotation speed calculation means 33 vehicle speed calculation means 34 accelerator opening calculation means 35 current gear ratio calculation means 36 target gear ratio calculation means 37 gear ratio deviation calculation means 38 target Hydraulic pressure calculation means 39 Solenoid drive signal calculation means 60 Time measurement processing section 61 First storage section 62 Second storage section 63 Initial pulse input information section 64 Initial pulse input flag 65 Pulse count processing section 66 Pulse counter 67 Rotational speed calculation processing Permit / Prohibit Switch 68 Rotational Speed Calculation Processing Unit 69 Pulse Count Processing Unit 70 Time Memory Processing Unit 71 Interrupt Processing Unit 72 Pulse Input Interrupt Processing Permit / Prohibit Switch 100 Automotive Y1-Y5 Hydraulic Circuit

Claims (2)

In a rotational speed calculation device for calculating the rotational speed of a gear provided in an engine or a transmission, the rotational speed calculation device comprising rotational speed calculation means for calculating the rotational speed by pulse input from a rotation sensor,
The rotation speed calculation means is processed by an interrupt processing section that processes the interrupt of the pulse input, a pulse input interrupt processing permission / prohibition means that permits / inhibits the interrupt processing in the interrupt processing section, and the interrupt processing section. A rotation speed calculation processing unit that calculates a rotation speed by the pulse input, and the interrupt processing unit counts the input pulse, and a time measurement process that measures the input time of the input pulse. And a time storage processing unit that stores the time measured by the time measurement processing unit, and when the number of pulses counted by the pulse count processing unit every predetermined time is equal to or greater than a predetermined value, An apparatus for calculating a rotational speed, wherein an interruption process in an interruption processing unit is prohibited.   The predetermined value of the number of pulses counted by the pulse count processing unit every predetermined time is determined by a rotation speed range that the rotation shaft of the gear can take in normal use and the number of teeth of the gear. The rotational speed calculation apparatus according to claim 1.

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