JPH08220121A - Vehicle speed detector - Google Patents

Abstract

PURPOSE: To obtain a vehicle speed detector for detecting even an extremely low traveling speed of a vehicle accurately. CONSTITUTION: When a low speed traveling state of a vehicle is determined by means 102 and a drive traveling state of vehicle is determined by means 104, a vehicle speed V detected based on an output signal from an output shaft rotation sensor 40 is switched and a temporary vehicle speed Vk is detected by means 106 based on an output signal from an input shaft rotation sensor 38. Even if the traveling speed of vehicle is extremely low, number of output pulses from the input shaft rotation sensor 38 per unit time is increased significantly thus ensuring the detection accuracy of vehicle speed sufficiently.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body speed detecting device for detecting a vehicle body speed during traveling.

[0002]

2. Description of the Related Art In order to detect the traveling speed of a vehicle, that is, the vehicle body speed, a rotation sensor for directly or indirectly detecting the rotation of an output shaft of a transmission or an axle operatively connected thereto is generally used. Used. The rotation signal output from the rotation sensor is in the form of a pulse, but has a vehicle body speed information itself, and is converted into a signal representing the vehicle speed as it is, or by undergoing appropriate signal processing. Then, it is sent to the electronic display of the instrument panel or the GPS navigation device.
In the electronic display of the instrument panel, the vehicle speed is displayed on the speedometer and the travel distance is displayed on the trip meter by processing the above signals as necessary. Further, in the GPS navigation device,
The speedometer calculates the vehicle speed and mileage by processing the above signals as necessary, and displays the current position of the vehicle based on them.

As the rotation sensor, for example, a photoelectric rotation sensor or an electromagnetic pickup type rotation sensor is used. The photoelectric rotation sensor is equipped with a large number of radial slits and rotates with the output shaft and axle of the transmission, and detects the passage of the rotor slits using light.
The photo coupler outputs a pulse signal each time the slit passes. Further, the electromagnetic pickup type rotation sensor includes a rotor made of a magnetic material having outer peripheral teeth and rotating with the output shaft, and a core made of a magnetic material fixed to the outer peripheral teeth of the rotor with a narrow gap. And an electromagnetic coil that outputs an induced electromotive voltage each time the outer peripheral teeth pass.

[0004]

The rotation signal output from the rotation sensor is a pulse signal having a cycle corresponding to the rotation speed of the output shaft of the transmission or the axle operatively connected to the output shaft. Therefore, if the traveling speed of the vehicle becomes extremely low, such as several km / h, due to the congestion of the road, the pulse period of the rotation signal becomes longer and the vehicle speed detected from the signal. The accuracy of is reduced. Particularly, when the rotation sensor is an electromagnetic pickup type including a rotor made of a magnetic material having outer peripheral teeth and an electromagnetic coil that outputs an induced electromotive voltage each time the outer peripheral teeth of the rotor pass. Since the induced electromotive voltage becomes lower as the vehicle body speed becomes lower, it becomes difficult to obtain the pulse signal corresponding to the passage of the outer peripheral teeth when the process for waveform shaping is performed. There was a downside.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle body speed detecting device capable of sufficiently obtaining detection accuracy even when the traveling speed of the vehicle is extremely low. To provide.

[0006]

The gist of the present invention for achieving the above object is to provide an output side rotation signal output from an output side rotation sensor for detecting rotation of an output side rotation member of an automatic transmission. In a vehicle body speed detection device of a type that detects the vehicle body speed based on (a) an input side rotation sensor that detects rotation of the input shaft of the automatic transmission, and (b) when the vehicle is running at a low speed below a predetermined vehicle speed. Low speed running state determining means for determining whether or not, (c) whether the power transmission direction of the automatic transmission is the driving running state of the vehicle, which is the direction from the input shaft to the output side rotating member. (D) When the vehicle is in the low speed traveling state and the vehicle is in the driving traveling state, the input speed is changed to the vehicle body speed detected based on the output side rotation signal. Output from side rotation sensor And a temporary vehicle body speed detecting means for detecting the temporary vehicle body speed based on the input side signal.

[0007]

With this configuration, when the low speed traveling state determining means determines that the vehicle is in the low speed traveling state and the driving traveling state determining means determines that the vehicle is in the driving traveling state, Instead of the vehicle body speed detected based on the output side rotation signal, the temporary vehicle body speed detection means detects the temporary vehicle body speed based on the input side signal output from the input side rotation sensor.

[0008]

Therefore, in the vehicle, since the input shaft of the automatic transmission is switched to the lower gear stage as the vehicle speed becomes lower, the rotational speed becomes higher than the output shaft rotational speed. Even if the traveling speed is extremely low, the number of pulses per unit time of the input side signal output from the input side rotation sensor is significantly increased, so the vehicle speed detected based on the output side rotation signal Instead, the temporary vehicle body speed is detected based on the input side signal output from the input side rotation sensor, whereby sufficient detection accuracy of the vehicle body speed can be obtained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram for explaining the structure of a vehicle equipped with a vehicle body speed detecting device according to an embodiment of the present invention. In the figure, the power output from the crankshaft 12 of the engine 10 is transmitted to the torque converter 14 and the automatic transmission 16, and further, from the automatic transmission 16 to the propeller shaft 18, the differential gear device 20, and the pair of axles. 22 _L and 22 _R and a pair of left and right drive wheels 24 _L and 24 _R
To each of them.

The automatic transmission 16 is described, for example, on pages 3-1 to 3-15 of "Toyota Crown Majesta New Model Car Manual" (published by Toyota Motor Corporation Service Department on October 11, 1991). Which is similar to an automatic transmission, the torque converter 1
4, an input shaft 26 connected to 4 and an output shaft 28 connected to the propeller shaft 18, and a plurality of sets of planets (not shown) for achieving a plurality of forward gears, for example, first to fourth gears. A gear unit and a plurality of hydraulic friction engagement devices, and a clutch drum 30 that is connected to the input shaft 26 when at least the first speed gear stage is achieved.
It has and. The automatic transmission 16 includes a plurality of one-way clutches (not shown) for switching gears by engaging or releasing one friction engagement device.
When the engine is not switched to the engine braking mode, when the power transmission direction is a non-driving state in which the power transmission direction is from the driving wheels 24 to the engine 10 as in coasting, the one-way clutch slips to rotate the input shaft 26. There may be a case where a constant relationship (N _IN = i × N _OUT : where i is a gear ratio) is not established between the speed N _IN and the rotation speed N _OUT of the output shaft 28.

The engine 10 of the vehicle is provided with an engine rotation sensor 34 for detecting the engine rotation speed N _E. Further, the housing 36 of the automatic transmission 16 is provided with an input shaft rotation sensor 38 for detecting the rotation of the input shaft 26 and an output shaft rotation sensor 40 for detecting the rotation of the output shaft 28. A shift operation position detection switch 42 for detecting the shift operation position P _SH of the forward drive range, the neutral range, the reverse drive range and the like selected by operating the shift lever is provided. In addition, the vehicle body also has a pair of left and right drive wheels 24 _L and 24 _R rotating speeds N _WL and N _WR.
A pair of wheel rotation sensors 44 _L and 44 _R are provided for detecting respectively.

As shown in detail in FIG. 2, the input shaft rotation sensor 38 has a large number of outer peripheral teeth 52 formed at equal angular intervals on the outer peripheral portion of a magnetic rotor 50 fixedly mounted on the clutch drum 30. Housing 3 to detect passage of
It is an electromagnetic pickup type sensor fixed to No. 6. The input shaft rotation sensor 38 includes a core 54 made of a magnetic material whose front end surface is close to the outer peripheral teeth 52 of the rotor 50, a coil 56 provided on the outer periphery of the core 54, and a base end surface of the core 54. The core 54 includes a permanent magnet 58 arranged in contact with each other to generate a magnetic flux in the longitudinal direction, a sensor housing 60 for accommodating them, and a tip cover 62 fixed to the sensor housing 60. When the outer peripheral teeth 52 of the rotor 50 pass near the tip of the core 54 as the rotor 50 rotates, the number of magnetic fluxes in the core 54 periodically changes to generate an induced electromotive force in the coil 56, which causes a unit time. A signal having a voltage change corresponding to the number of passing outer peripheral teeth 52 is output from the coil 56 through the lead wire 64. The output signal of the coil 56 is amplified by an amplifier circuit and a waveform shaping circuit (not shown) and shaped into a rectangular pulse signal, and then the electronic control unit 8 to be described later.
4 is supplied.

The output shaft rotation sensor 40 is shown in FIG.
As shown in FIG. 6, the housing 36 is provided to detect the passage of a large number of outer peripheral teeth 68 formed at equal angular intervals on the outer peripheral portion of the magnetic rotor 66 fixed to the output shaft (output side rotating member) 28. It is an electromagnetic pickup type sensor fixed to. The rotor 66 has a diameter smaller than the rotor 50 by a factor of a few and has a smaller number of teeth G _OUT than the number of teeth G _IN . Also in the output shaft rotation sensor 40, a core 70 made of a magnetic material and having a tip end surface close to the outer peripheral teeth 68 of the rotor 66, and a coil 72 provided on the outer periphery of the core 70.
And a permanent magnet 74 arranged in contact with the base end surface of the core 70 to generate a longitudinal magnetic flux in the core 70,
A sensor housing 76 for accommodating them and a tip cover 78 fixed thereto are provided. When the outer peripheral teeth 68 of the rotor 66 pass near the tip of the core 70 as the rotor 66 rotates, the number of magnetic fluxes in the core 70 is periodically changed to generate an induced electromotive force in the coil 72, which causes a unit time. A signal having a voltage change corresponding to the number of passing outer peripheral teeth 68 is output from the coil 72 through the lead wire 80. The output signal of the coil 72 is also amplified by an amplifying circuit and a waveform shaping circuit (not shown) and shaped into a rectangular pulse signal before being supplied to an electronic control unit 84 described later.

Wheel rotation sensors 44 _L and 44
_R is fixed to the vehicle body to detect the passage of a large number of outer peripheral teeth formed at equal angular intervals on the outer peripheral portions of magnetic rotors 82 _L and 82 _R fixed to the axles 22 _L and 22 _R. An electromagnetic pickup type sensor having the same configurations as the input shaft rotation sensor 38 and the output shaft rotation sensor 40, and their output signals are amplified in an amplifier circuit and a waveform shaping circuit (not shown). The waveform is shaped into a rectangular pulse signal and then supplied to an electronic control unit 84 described later.

The electronic control unit 84 includes ROM, RAM, and C.
A so-called microcomputer including a PU, an input / output interface, etc., which processes an input signal according to a program stored in advance in a ROM while utilizing a temporary storage function of a RAM, and displays a signal representing a vehicle speed V and a traveling distance D in speed. Drive circuit 86 and trip meter drive circuit 8
8 and outputs the vehicle speed V to the speed display 90.
The travel distance D is displayed on the trip meter 92 as an analog display or a numerical display. The speed indicator 90 and the trip meter 92 are arranged, for example, in an instrument panel 94 located in front of the driver.

FIG. 4 is a functional block diagram showing a main part of the arithmetic control function of the electronic control unit 84. In the figure, a vehicle body speed detecting means 100 detects a vehicle body speed V based on an output side rotation signal output from an output shaft rotation sensor 40 which detects a rotation of an output shaft 28 of an automatic transmission 16. The low speed traveling state determination means 102 determines, based on the vehicle body speed V, whether the vehicle is in a low speed traveling state below a predetermined level. Further, the driving traveling state determination means 104 determines whether or not the vehicle is in a driving traveling state (so-called power-on traveling) in which the power transmission direction of the automatic transmission 16 is from the input shaft 26 to the output shaft 28. judge. The temporary vehicle body speed detecting means 106 rotates the output side when the low speed traveling state determining means 102 determines the low speed traveling state of the vehicle and the driving traveling state determining means 104 determines the vehicle driving traveling state. Instead of the vehicle body speed V detected based on the signal, the temporary vehicle body speed V _k is detected based on the input side signal output from the input shaft rotation sensor 38.

FIG. 5 is a flow chart for explaining a vehicle body speed calculation routine which is a main part of the arithmetic control operation of the electronic control unit 84. In the figure, in step SA1 (hereinafter, step is omitted) corresponding to the low speed traveling state determination means 102, the output shaft rotation speed N _OUT detected based on the output side rotation signal from the output shaft rotation sensor 40 is set in advance. Whether it is lower than the set reference value N _AO , that is, the vehicle speed V (= N _OUT × _id × 60 × 2π)
R _t × 10 ⁻³ km / h: where i _d is the gear ratio of the differential gear device 20, and R _t is the diameter of the drive wheels 24 _L and 24 _R ) is the reference value V _AO (= N _AO ×) i _d × 60 × 2πR _t / 10 ³ km
/ h). This judgment reference value V
_AO is set to a value such that the vehicle reliably travels to the first gear and the vehicle speed V based on the output shaft rotation speed N _OUT does not provide sufficient accuracy, for example, a value of about 4 to 5 km / h. To be done.

If the determination at SA1 is negative,
In SA5 corresponding to the vehicle body speed detecting means 100, a calculation formula (= N _OUT × _id × 60 × 2) stored in advance is stored.
πR _t / 10 ³ km / h) to actual output shaft rotation speed N _OUT
The vehicle body speed V is calculated based on the above, and a signal representing it is output. The output shaft rotation speed N _OUT (min
^-1 ) is the rotor 6 used for the output shaft rotation sensor 40
6 the number of teeth of the G _OUT, the number of pulses per unit time of the output-side signals output from the output shaft rotation sensor 40 n _{OU T}
If (1 / min), it is calculated by n _OUT / G _OUT . At the same time, in SA5, the current traveling distance D is calculated by adding the traveling distance per unit time calculated from the vehicle body speed V to the previous traveling distance, and this is output.

However, if the determination at SA1 is affirmative, it is determined at SA2 whether or not the engine 10 is operating based on the engine speed N _E. If the determination at SA2 is negative, the SA5 is executed, but if the determination is affirmative, at SA3, it is determined whether or not the shift lever is operated to the traveling (R, D, 2, L) range. To be judged.

If the determination at SA3 is negative,
Since SA5 is executed because it is in the N or P range, in the affirmative case, in SA4, the shift lever moves from the neutral (P, N) range (R, D, 2,
L) It is determined whether or not the elapsed time T counted after being operated to the range exceeds a preset determination reference value t _O. This judgment reference value t _O is the shift lever neutral (P,
The response time until the gear stage of the automatic transmission 16 is achieved and power can be transmitted when operating from the N) range to the traveling (R, D, 2, L) range or a slight margin value thereof The added time is set to, for example, about 1 second. In the present embodiment, SA2, SA3, and SA4 correspond to the driving traveling state determination means 104.

When the determination at SA4 is negative, SA5 is executed, but when the determination at SA4 is affirmative, the vehicle is running at a low speed, and the automatic transmission 16 is operated by the input shaft 2 thereof.
Since the direction from 6 to the output shaft 28 is a power transmission state of transmitting power, at SA6, the previously stored calculation formula _{(= N IN × i 1ST ×} i d × 60 × 2πR t / 10 3 km /
h: However, i _1ST is the gear ratio of the first gear of the automatic transmission 16. ), The temporary vehicle body speed V _k is calculated and output based on the actual input shaft rotation speed N _IN . Note that the input shaft rotation speed N _IN (min ⁻¹ ) is obtained by setting the number of teeth of the rotor 50 used for the input shaft rotation sensor 38 to G _IN ,
If the number of pulses per unit time of the input side signal output from the input shaft rotation sensor 38 is n _IN (1 / min), then n
Calculated by _IN / G _IN . At the same time, in SA6,
The current traveling distance D is calculated by adding the traveling distance per unit time calculated from the provisional vehicle body speed V _k to the previous traveling distance, and this is output.

As described above, according to this embodiment, the fact that the vehicle is in the low speed traveling state means that the vehicle is in the low speed traveling state.
When the determination is made by SA1 corresponding to the above, and when it is determined by SA2 through SA4 corresponding to the drive traveling state determination means 104 that the vehicle is in the drive traveling state, the output side signal output from the output shaft rotation sensor 40. Instead of the vehicle body speed V detected based on the (output shaft rotation speed N _OUT ), the input side signal (input shaft rotation speed) output from the input shaft rotation sensor 38 is output by SA6 corresponding to the temporary vehicle body speed detection means 106. The temporary vehicle body speed V _k is detected based on N _IN ). Generally, in a vehicle, the input shaft 26 of the automatic transmission 16 has a rotation speed higher than the output shaft rotation speed N _OUT by being switched to a lower gear as the vehicle body speed V becomes lower. Even when the traveling speed of the vehicle is extremely low, the number of pulses per unit time of the input side signal output from the input shaft rotation sensor 38 is significantly increased, so the vehicle body detected based on the output side rotation signal. Instead of the speed V, the temporary vehicle body speed V _k is detected based on the input side signal output from the input shaft rotation sensor 38, whereby sufficient detection accuracy of the vehicle body speed can be obtained. That is, when the temporary vehicle body speed V _k is detected based on the input side signal output from the input shaft rotation sensor 38, the speed indicator 90, the trip meter 92,
Alternatively, it becomes possible to sufficiently obtain the detection accuracy of the vehicle speed and the traveling distance in the GPS navigation device (not shown).

Further, in this embodiment, the input shaft rotation sensor 3
The rotor 50 used in No. 8 has a diameter several times larger than that of the rotor 66 used in the output shaft rotation sensor 40, and the number of teeth G _IN of the rotor 50 is significantly larger than the number of teeth G _OUT of the rotor 66. The advantage is that the accuracy of the temporary vehicle body speed V _k calculated from the input side signal (input shaft rotation speed N _IN ) output from the input shaft rotation sensor 38 can be further enhanced.

Further, in this embodiment, the output from the input shaft rotation sensor 38 is output only when the power transmission state in which the automatic transmission 16 transmits power from the input shaft 26 to the output shaft 28 is determined. Since the temporary vehicle body speed V _k is detected based on the input side signal (input shaft rotation speed N _IN ), the accuracy is further enhanced. Even when the vehicle is running at a low vehicle speed, when the engine 10 is driven by the drive wheels 24 _L and 24 _R , the input shaft is slipped due to the slip of the one-way clutch in the automatic transmission 16. Rotation sensor 3
Therefore, the accuracy of the temporary vehicle body speed V _k calculated from the input side signal (input shaft rotation speed N _IN ) output from 8 may decrease.

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment will be designated by the same reference numerals and the description thereof will be omitted.

FIGS. 6 and 7 are views corresponding to FIGS. 1 and 5, respectively, in another embodiment of the present invention. In FIG. 6, the electronic control unit 84 supplies a pulse-shaped vehicle speed signal to the speed meter PLA (blog programmable logic array) 110 and the trip meter PLA 112. The PLAs 110 and 112 are logic circuits that convert the period of the pulse-shaped vehicle speed signal into a numerical value indicating the vehicle speed or the traveled distance. The PLA 110, 112 outputs a drive signal for displaying the speed and the traveled distance to the speed indicator 90 and the trip meter 92. Supply to.

In FIG. 7, SB1 to SB4 are the same as SA1 to SA4 in FIG. When the vehicle is traveling at a relatively high vehicle speed in a gear higher than the first gear or at a relatively low vehicle speed in the first gear, the vehicle is driven (so-called power-off traveling). In SB5 (corresponding to the vehicle body speed detecting means 100) executed when the vehicle is in the state, the vehicle body speed V is obtained by a pulsed vehicle speed signal having the same cycle as the output side signal output from the output shaft rotation sensor 40, that is, the pulse cycle. Is output. But first
In SB6 (corresponding to the temporary vehicle body speed detecting means 106) which is executed when the vehicle is traveling at a relatively low vehicle speed in the high speed gear stage and is in the driving traveling state of the vehicle, the input shaft rotation sensor 38 outputs. A vehicle speed signal is generated and output based on the input side signal. For example, when the number of pulses of the input side signal output from the input shaft rotation sensor 38 is n _IN (1 / min), the number of teeth G of the rotor 66 is G.
The gear ratio between the teeth number G _IN of _{OU T} and rotor 50 (G _OUT /
G _IN ) is the number of pulses n of the input side signal per unit time
It is converted into the vehicle speed signal or signal representative of the provisional vehicle speed V _k by the pulse period in the same prerequisites and the output-side signal with _IN pulse number obtained by multiplying the a _{(n IN · G OUT / G} IN), is and output . That is, the input shaft rotation sensor 3
The temporary vehicle body speed V _k based on the input side signal output from
Is detected.

In this embodiment as well, the fact that the vehicle is in the low speed traveling state corresponds to the low speed traveling state determining means 102.
When it is determined by B1 and also by SB2 to SB4 corresponding to the drive traveling state determination means 104 that the vehicle is in the drive traveling state, the output shaft rotation sensor 4
In place of the vehicle speed signal (output side signal) output from 0 indicating the vehicle speed V, S corresponding to the temporary vehicle speed detecting means 106.
Since B6 outputs the vehicle speed signal indicating the temporary vehicle body speed V _k based on the input side signal output from the input shaft rotation sensor 38, the same effect as the above-described embodiment can be obtained.

While one embodiment of the present invention has been described with reference to the drawings, the present invention can be applied to other embodiments.

For example, the input shaft rotation sensor 38 of the above-described embodiment detects the rotation of the clutch drum 30 which rotates integrally with the input shaft 26 via the clutch when at least the first speed gear is achieved. However, the rotational speed of the turbine shaft of the input shaft 26 or the torque converter 14 integrally connected to the input shaft 26 may be detected. In addition, the output shaft rotation sensor 4 of the above-described embodiment
0 uses the rotor 66 fixed to the output shaft (output side rotating member) 28 to directly detect its rotation, but it detects it via a cable operatively connected to the output shaft 28. It may be one that does.

Although the output shaft rotation sensor 40 is used to detect the rotation of the output shaft 28 in the above-described embodiment, the wheel rotation sensors 44 _L and 44 _R may be used. In this case, the rotation speed of the drive wheel 24 _L detected based on the wheel rotation sensor 44 _L is N _WL, and the rotation speed of the drive wheel 24 _R detected based on the wheel rotation sensor 44 _R is N _WR . Then, the output shaft speed N _OUT is calculated by _{(N WL + N WR) /} 2i d, the vehicle speed V _{[(N WL + N WR) /} 2 ] × 60 × 2 [pi
Calculated as R _t × 10 ⁻³ km / h.

Further, in the above-described embodiment, the low speed running state judgment is performed.
The fixing means 102 determines the output shaft rotation speed N. _OUTIs the criterion value N
_AOWhen the vehicle is running at a lower speed
However, the actual gear stage of the automatic transmission 16 is the first gear stage.
It is possible to judge the low vehicle speed running state based on the fact that
Yes. Even in this way, the object of the present invention can be achieved.

Further, in the above-described embodiment, the drive / running state determination means 104 is such that the engine 10 is operating, the shift lever is operated to the travel range, and further, the shift lever is operated to the travel range. When the time T exceeds the judgment reference value t _O , the drive running state of the vehicle is determined. However, for example, the drive running state of the vehicle is determined based on the positive / negative of the signal from the torque sensor, or the throttle opening degree is determined. It is also possible to detect a state in which the vehicle body speed V is equal to or higher than a predetermined determination reference value, but is not in the non-driving traveling state, even though is zero. Also, in FIG. 5, SA4
Even if it is not necessarily provided, you can enjoy a temporary effect.

Further, the electronic control unit 84 of the above-mentioned embodiment is used.
May be shared with other electronic control devices such as an engine control electronic control device and a shift control electronic control device.

Although not illustrated one by one, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a vehicle power transmission device including a vehicle body speed detection device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating in detail the configuration of the input shaft rotation sensor of the embodiment of FIG.

FIG. 3 is a cross-sectional view illustrating in detail the configuration of the output shaft rotation sensor of the embodiment of FIG.

FIG. 4 is a functional block diagram illustrating a main part of an arithmetic control function of the electronic control device according to the embodiment of FIG.

5 is a flowchart illustrating a main part of a control operation of the electronic control device according to the embodiment of FIG.

FIG. 6 is a view corresponding to FIG. 1 of another embodiment of the present invention.

7 is a flowchart illustrating a main part of a control operation of the electronic control unit according to the embodiment of FIG. 6, and is a diagram corresponding to FIG.

[Explanation of symbols]

 16: Automatic transmission 26: Input shaft 28: Output shaft 38: Input shaft rotation sensor (input side rotation sensor) 40: Output shaft rotation sensor (output side rotation sensor) 100: Vehicle speed detection means 102: Low speed running state determination means 104: driving traveling state determination means 106: temporary vehicle body speed detection means

Claims (1)

[Claims] 1. A vehicle body speed detecting device of a type that detects a vehicle body speed based on an output side rotation signal output from an output side rotation sensor that detects rotation of an output side rotating member of an automatic transmission, wherein the automatic transmission An input side rotation sensor for detecting the rotation of the input shaft, a low speed running state determining means for determining whether the vehicle is in a low speed running state below a predetermined vehicle speed, and a power transmission direction of the automatic transmission Driving direction determination means for determining whether or not the vehicle is in the driving traveling state in the direction from the output side rotating member to the output side rotating member; and when the vehicle is in the low speed traveling state and the vehicle is in the driving traveling state, In addition to the vehicle body speed detected based on the output side rotation signal, temporary vehicle body speed detecting means for detecting the temporary vehicle body speed based on the input side signal output from the input side rotation sensor is included. Vehicle speed detecting device according to.