JP2000088088A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To properly control a vehicle using a magnetic type revolving speed sensor even in an environment involving noise resulting from a road surface heater. SOLUTION: A magnetic type revolving speed sensor senses the revolving speed NIP input from a clutch to a transmission. An automatic clutch device uses this revolving speed NIP for controlling the clutch. The input revolving speed NIP remains zero as long as the ignition switch is turned off (S10), and therefore, it is judged that noises resulting from the AC current of a road surface heater are superposed on the sensing signals unless the sensing value of NIP is zero (S14). The failsafe process (S16) includes prohibition of the control based upon the revolving speed signal exhibiting under the revolving speed level corresponding to the frequency (60 Hz) of the road surface heater, when the control takes place with a greater revolving speed sensing signal. Accordingly the vehicle can be run while a clutch control is performed in such a way that ill influence of noises is precluded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle control device for controlling a vehicle based on a rotational speed signal output from a magnetic rotational speed sensor, and more particularly to an appropriate control in a noisy environment.

[0002]

2. Description of the Related Art Conventionally, vehicles have been equipped with various control devices utilizing detection signals of a magnetic rotational speed sensor. Here, an automatic clutch device will be described as an example of such a control device.

[0003] A conventional general automobile is provided with a friction clutch device between an engine and a manual transmission. When the driver operates the clutch pedal with his / her foot, the friction clutch is disconnected according to the pedal operation. An automatic clutch device eliminates the need for a driver to operate a pedal and controls the clutch using a hydraulic actuator. The automatic clutch device
This can be realized by adding a hydraulic pump, a hydraulic cylinder, a valve mechanism for controlling the flow of oil, and the like to the conventional manual transmission.

In an automatic clutch device, the output rotation speed of a clutch, that is, the input rotation speed of a transmission is detected by using a rotation speed sensor, and control is performed based on a detection signal. The detection signal is used, for example, to determine whether the clutch has been engaged. It is preferable to use an inexpensive and easily available magnetic sensor (such as an MPU type) as the rotation sensor.

[0005]

By the way, in a cold region, a road heater for melting snow is embedded in a road surface such as a sloping road to prevent wheel slip. FIG.
As shown in the figure, the uphill road surface 100 and the downhill road surface 10
A road heater 104 for snow melting is installed under the second road surface. The heat generated by the road surface heater 104 melts snow on the road surface and prevents freezing of the road surface, thereby preventing wheel slip.

The heater current (60
Hz AC current) and an AC magnetic field is generated on the heater. If the vehicle is located in such a place, noise due to the AC magnetic field is mixed with and superimposed on the detection signal of the rotational speed sensor, and thus the rotational speed may be erroneously detected. It is desired not to perform inappropriate vehicle control due to such erroneous detection.

In Japanese Patent Application Laid-Open No. 9-226548, control is performed in consideration of heater noise. This publication exemplifies a traction control device and an antilock brake device as control objects. It is determined whether the noise of the road surface heater is superimposed on the detection signal of the rotation speed sensor. As the fail-safe control when the noise is superimposed, the control is mainly prohibited, that is, the traction control control or the antilock brake control is prohibited.

However, in the case of an automatic clutch device,
It is not preferable to prohibit the clutch control just because the occurrence of the noise and the erroneous detection is found. If the clutch control is prohibited, the clutch is maintained in the engaged state or the disengaged state, so that the engine cannot be started and the vehicle cannot move forward. Therefore, it is desired that control can be continued even when external noise is found.

In the above description, the automatic clutch device has been described, but a similar problem may occur in other vehicle control devices.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a vehicle control device capable of appropriately controlling a vehicle even in an environment where noise is mixed in a detection signal of a rotation speed sensor. .

[0011]

A vehicle control device according to the present invention includes a noise determination unit. The noise determination unit determines whether a rotation speed signal output from a magnetic rotation speed sensor includes external noise due to a magnetic field. Is determined. When the noise is superimposed, control of the vehicle based on a rotation speed signal equal to or lower than a predetermined rotation speed corresponding to the frequency of the external noise is prohibited. However, a rotation speed signal higher than the predetermined rotation speed is allowed, and the vehicle is controlled using such a rotation speed signal.

As described above, according to the present invention, vehicle control based on the rotational speed signal affected by noise is prohibited, so that vehicle control based on an erroneous signal can be prevented. On the other hand, since the vehicle control is performed by allowing the rotation speed signal not affected by the noise, the control prohibition can be minimized. Therefore, even in an environment where external noise exists, it is possible to control the vehicle using the rotation speed signal while preventing the noise from being adversely affected.

The predetermined rotation speed is determined, for example, in accordance with the frequency of the AC current for the heater of the road surface heater.
When the frequency is 60 Hz, the predetermined rotation speed is 60H
It is set equal to z or a frequency with a margin slightly larger than z.

For example, the control target of the vehicle control device is an automatic clutch device that automatically controls a clutch connecting the engine and the transmission, and the magnetic rotational speed sensor detects an input rotational speed from the clutch to the transmission. It is a sensor to detect. If a rotation sensor is mounted on the lower surface of the transmission or the like, it is susceptible to external noise, but even in this case, the present invention provides suitable control.

Here, the frequency of the road heater noise usually corresponds to about several tens of revolutions (per minute) of the input portion of the transmission.
Even if a detection signal at a rotational speed lower than this level is not used, the influence on the clutch control is small. Therefore, according to the present invention, control is performed based on the detected values in the entire rotational speed range in an environment without noise, and even in a noise environment, control is performed as appropriate as possible by ignoring only detected values in a narrow speed range. It can be planned as follows.

[0016]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. In the present embodiment, the vehicle control device is an automatic clutch device, and the magnetic rotation speed sensor detects the output rotation speed of the clutch, that is, the input rotation speed of the transmission.

FIG. 1 is a schematic configuration diagram of a power plant including an automatic clutch device. The power plant 10 includes an engine 12, a clutch 14, and a transmission 16. The engine 12 is controlled in the same manner as a currently used engine, by determining a fuel injection amount and the like based on information from various sensors for detecting the operating state of the engine. An engine ECU (engine electronic control unit) 18 controls the engine, and includes, for example, a water temperature sensor 20 for detecting a cooling water temperature, a throttle sensor 22 for detecting an opening of a throttle valve, and a rotational speed of the engine. And a signal from an intake pipe pressure sensor 25 for detecting the pressure in the intake pipe. The engine rotation speed sensor 24 includes a gear fixed to the crankshaft and an electromagnetic pickup for detecting the teeth, and outputs a high signal when the gear teeth face the sensor and a low signal when the gear valley faces the sensor. . Therefore, the engine speed sensor 2
4 outputs a square wave having a frequency corresponding to the engine rotation speed. The engine ECU 18 calculates the rotational speed of the engine from the frequency of the square wave, and performs control according to the calculated rotational speed.

The transmission 16 is a synchronous mesh type manual transmission, and a gear is selected by a driver's operation of a shift lever 26 similarly to a normal manual transmission. That is, the operation of the shift lever 26 is transmitted to the shift arm 30 via the shift wire 28, and the shift fork and sleeve in the transmission 16 are moved to select a gear.

FIG. 2 schematically shows the structure of the clutch 14. The basic configuration is the same as that of the conventional clutch. Engine 12 crankshaft 32
Is connected to a flywheel 34, and a friction surface that contacts the friction disk 36 is formed on the right surface in the figure. The friction disk 36 is disposed at the tip of an input shaft 38 that is an output shaft of the clutch 14 and an input shaft of the transmission 16. A spline 40 is formed at the tip of the input shaft 38, and the friction disk 36 is also provided with a spline that meshes with the spline 40. Therefore, the movement of the friction disk 36 is restricted in the rotation direction of the input shaft 38, and the friction disk 36 rotates with the shaft while being slidable in the axial direction. At a position facing the friction disk 36, a pressure plate 42 is disposed.
A diaphragm spring 44 is disposed on the back surface of the. When the clutch is connected, the diaphragm spring 44
The urging force causes the pressure plate 42 to press the friction disk 36 against the flywheel 34.
Thus, the output of the engine 12 is transmitted to the input shaft 38.

A release bearing 46 is arranged on the input shaft 38 at a position in contact with the inner peripheral portion of the diaphragm spring 44. The release bearing 46 slides on the input shaft 38 by the swing of the release fork 48. Release fork 48
Is in contact with the rod 52 of the release cylinder 50 at the end opposite to the end in contact with the release bearing 44. Fluid is supplied to the release cylinder 50 from a fluid pressure pump 54 (see FIG. 1) via a fluid pressure line, and the rod 52 moves forward and backward. Details of the fluid pressure system will be described later. The amount of advance and retreat of the rod 52, that is, the amount of stroke of the clutch 14 is determined by the release cylinder 50.
Is detected by a stroke sensor 56 fixed at
The stroke sensor 56 is a sliding resistor type sensor in the present embodiment, and outputs a voltage according to the movement of the rod 52.

An input shaft rotation speed sensor 58 for detecting the rotation speed of the input shaft 38 is provided.
Is provided. This rotation speed sensor 58
It has a gear 60 fixed on the input shaft 38 and an electromagnetic pickup 62 for detecting the teeth. The input shaft rotation speed sensor 58 outputs a square wave having a frequency corresponding to the rotation speed, similarly to the engine rotation speed sensor 24. Although the sensor 58 is shown on the side of the transmission 16 in FIG. 1 for convenience, it is actually provided below the transmission 16 and is located close to the road surface. This position setting complies with the space restriction of avoiding a shift cable or the like.

FIG. 3 shows a hydraulic circuit for operating the clutch 14. The working fluid of the fluid pressure system is preferably a relatively high viscosity and incompressible liquid. In this embodiment, a general brake fluid is used.
The fluid pressure pump 54 sends the fluid stored in the reservoir 64 to the accumulator 68 via the check valve 66. Thereby, the high-pressure fluid is stored in the accumulator 68. The pressure in the accumulator 68 is detected by the pressure switch 70. If the pressure does not reach the specified value, the hydraulic pump 54 is activated to increase the pressure, and when the pressure reaches the specified value, the hydraulic pump 54 is stopped. . The fluid stored in the accumulator 68 is sent to the release cylinder 50 by controlling the solenoid valve 72. As a result, the rod 52 of the release cylinder 50 advances, and pushes the release fork 48. Also,
When retracting the rod 52, the release cylinder 5
The fluid in 0 is withdrawn by controlling the solenoid valve 72 and sent to the reservoir 64.

Returning to FIG. 1, it is the automatic clutch ECU (automatic clutch electronic control unit) 74 that controls the solenoid valve 72. The automatic clutch ECU 74 receives an engine rotation pulse NEP and an engine rotation speed NED from the engine ECU 18. The stroke amount VCRC of the release fork 48 from the stroke sensor 56, the pulse output NIP of the input shaft rotation speed sensor 58, the output P of the pressure switch 70, and the output CN of the neutral switch 75 for detecting that the transmission is in the neutral state. , The output SS of the shift lever switch 78 for detecting that the shift lever has been operated and the output V (SP) of the vehicle speed sensor 76 for detecting the speed of the vehicle.
D) is also input. Further, the output of the brake switch 80 for detecting whether the brake is being operated and the output of the door courtesy switch 82 are also input.

On the basis of these input signals, the automatic clutch ECU 74 controls the solenoid valve 72 and the fluid pressure pump 54 to control the automatic clutch. When an abnormality occurs in the system, the warning light 84 is turned on to call the driver's attention.

Next, an outline of the operation of the automatic clutch will be described. At the time of starting the engine, before the ignition switch is turned to the engine start position, the fluid is sent to the release cylinder 50 at the ON position before the clutch is disengaged. After the engine is started, the vehicle is stopped, and after it is confirmed that the transmission 16 is in neutral, the clutch is controlled to the connected side. When the clutch is gradually engaged and the input shaft 38 starts rotating, this is the clutch engagement position, and the output value of the stroke sensor 56 at this time is stored. Thereby, the stroke amount at the touch point of the clutch is learned. And
The clutch is again disengaged. When the gear is selected by the shift lever 26 and the rotation of the engine increases, the clutch is controlled to the connected side accordingly. At this time, since the clutch connection position is determined at the time of engine start, the clutch is quickly returned to this position, and thereafter, the solenoid valve 72 is controlled by referring to the rotational speeds of the engine 12 and the input shaft 38, and the release cylinder is controlled. The amount of working fluid sent to 50 is controlled. Thereby, the operation of the clutch is performed.

At the time of a shift change operation, when the shift lever 26 is operated while the vehicle is running, the solenoid valve 7 is operated so that fluid is sent to the release cylinder 50.
2 is controlled. As a result, the clutch enters a disconnected state. Further, when the gear is selected by operating the shift lever 26, the solenoid valve 72 is controlled so as to remove the fluid from the release cylinder 50, and the clutch is engaged.

"Countermeasure for extraneous noise" As described above, in the automatic clutch system, the input rotation speed NIP (pulse signal) of the transmission is used for clutch control. If the number of revolutions per minute NIP matches the engine speed,
It can be seen that the clutch is in the engaged state.

However, on a road provided with a road heater, an AC magnetic field of a heater current acts on the input shaft rotation speed sensor 58. A relatively inexpensive magnetic pickup type sensor is employed as the rotation speed sensor 58, and the sensor 58 is provided below the transmission 16 due to space restrictions. Therefore, the sensor 58 is easily affected by the AC magnetic field of the heater current. Then, as a result of the noise caused by the AC magnetic field being superimposed on the detection signal, the input rotation speed NIP is erroneously detected.

For example, when shifting from the clutch disengagement mode to the connection mode, the rotation of the input shaft 38 is detected even though the clutch is not yet connected, and it is erroneously determined that the clutch is engaged. This is a problem particularly in the operation of detecting the touch point of the clutch at the time of starting the system. Since the clutch wears with use, the stroke amount at the time of the clutch meet also changes.
Therefore, as described above, at the time of starting the system, the clutch is gradually connected, and the stroke amount when the input shaft 38 starts rotating (that is, when the rotational speed NIP is not 0) is obtained. However, if the vehicle is parked on the road heater, the clutch touch point cannot be obtained. This is because even when the clutch is not connected, the rotation speed NIP is not zero due to the heater noise. If a touch point is not required, subsequent control operations may not be able to be performed.

Therefore, in the present embodiment, the occurrence of erroneous detection of the rotational speed sensor 58 is determined as follows, and fail-sale control is performed based on the determination result.

[Noise Detection] FIG. 4 is a flowchart showing the noise determination processing of the present embodiment. The noise determination process is performed by the automatic clutch ECU 74 functioning as the noise determination unit of the present invention based on the input information. When the user opens the door of the vehicle, a signal indicating that the door has been opened is input from the door courtesy switch 82 to the automatic clutch ECU 74. After receiving this signal, the automatic clutch EC
The power supply of U74 is turned on, and the processing of the flowchart of FIG. 4 is started.

First, in S10 and S12, it is determined whether or not the input rotational speed NIP is in a state "should be zero". In S10, it is determined whether or not the ignition switch is off. If the ignition switch is off, the engine has stopped and the rotational speed NIP should be zero. If S10 is NO, the same judgment is repeated.

If S10 is YES, the vehicle speed S is determined at S12.
PD is 0 (including values below a predetermined speed close to 0)
Is determined (S12). The vehicle speed SPD is obtained from a detection signal of the vehicle speed sensor 76. Vehicle speed sensor 7
6 (MRE) is provided in a place that is hardly affected by the AC magnetic field by the road surface heater, and a relatively reliable detection result can be obtained. If the vehicle speed SPD is not 0, S10
Return to the judgment. On the other hand, if the vehicle speed SPD is 0, the input rotation speed NIP should also be 0, and the process proceeds to S14.

The judgment step of S12 is provided for confirmation. Since the input shaft 38 can be found to be in the stopped state only by determining whether the ignition switch is turned off in S10, the step of S12 may be omitted as appropriate.

Next, at S14, the input rotation speed N actually detected by the input shaft rotation speed sensor 58
The IP is referred to, and it is determined whether or not NIP = 0 (however, includes a predetermined number of revolutions less than or equal to 0). initially,
From the determination results in S10 and S12, the rotation speed NIP is "should be zero". Therefore, if S14 is YES, it is determined that it is not affected by the road heater, and S10 is determined.
Return to

On the other hand, if NIP is not 0 in S14, it is considered that the detection signal of the input shaft rotation speed sensor 58 contains noise due to the influence of the magnetic field of the road surface heater. Therefore, the process proceeds to S16 to execute the fail-safe process.

"Fail-safe processing" In normal control without fail-safe processing, the entire input rotational speed NIP is used for clutch control. However, in the fail-safe process, clutch control is performed based on a detection signal indicating a rotation speed greater than the frequency (60 Hz) of the heater current.

More specifically, a reference rotation speed (a threshold rotation speed) that is somewhat higher than a rotation speed corresponding to a frequency of 60 Hz is set in advance. Automatic clutch ECU
The reference numeral 74 ignores a detection signal even when a rotation speed lower than the reference rotation speed is detected by the rotation speed sensor 58, that is, prohibits control based on the detection signal. On the other hand, if a rotation speed greater than the reference rotation speed is detected, the clutch is controlled based on the rotation speed.

As described above, according to the present embodiment, the control based on the detection value included in the rotational speed range affected by the noise is prohibited as the fail-safe processing, so that the control based on the erroneous detection signal is disabled. Appropriate control can be prevented. On the other hand, clutch control is performed using a detection signal in the rotation speed range where there is no problem of the influence of noise. Therefore, it is possible to drive the vehicle by controlling the clutch while preventing the noise from being adversely affected.

If a normal magnet pickup type rotation speed sensor is used, the input rotation speed NIP corresponding to a frequency of 60 Hz is several tens of rotations per minute (for example, about 50 rpm).
m). On the other hand, the entire speed range of the input shaft is equal to the engine speed range and is considerably wide. According to the present embodiment, only the use of the detection signal in the extremely low rotation region of several tens of revolutions per minute or less (or a slightly wider range) is prohibited. However, since the detection signals in other wide areas are used for the control, the clutch control can be performed almost in the same manner as usual, though somewhat rough. The user hardly feels a sense of discomfort such as a shock when the clutch is engaged. As described above, according to the present embodiment, control is performed based on the detection values in the entire rotation speed range under an environment without noise, and even under a noise environment, only the detection values in a narrow rotation speed range are excluded, and the control is almost normal. It is possible to perform appropriate control as much as possible.

Note that the present invention is not limited to the above embodiment. The present invention is applicable to vehicles other than the engine-equipped vehicle, for example, electric vehicles or hybrid vehicles. The present invention is also applicable to a vehicle control device other than the automatic clutch control device.

[0042]

According to the present invention, even when noise is superimposed on the detection signal of the rotational speed sensor, vehicle control using the detected value affected by the noise is prohibited, but the influence of the noise is suppressed. The vehicle control is allowed by using the detection signal in the rotation speed range that is not available. Therefore, it is possible to control the vehicle while suppressing the control prohibition to the minimum necessary while preventing the adverse effect of the noise.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a power plant having an automatic clutch according to an embodiment.

FIG. 2 is a diagram schematically showing a configuration of a clutch.

FIG. 3 is a diagram showing a fluid pressure circuit of the automatic clutch.

FIG. 4 is a flowchart for determining the generation of noise due to the alternating current of the road heater.

FIG. 5 is a diagram showing a road heater installed on a road.

[Explanation of symbols]

Reference Signs List 10 power plant, 12 engine, 14 clutch, 16 transmission, 18 engine ECU, 34 flywheel, 36 friction disk, 38 input shaft, 58 input shaft rotation speed sensor, 72 solenoid valve, 74 automatic clutch E
CU, 76 Vehicle speed sensor.

Claims (4)

[Claims] 1. A vehicle control device for controlling a vehicle based on a rotation speed signal output from a magnetic rotation speed sensor, wherein a noise determination for determining whether the rotation speed signal includes external noise due to a magnetic field. Means, when external noise is included, prohibits control of the vehicle based on a rotation speed signal equal to or lower than a predetermined rotation speed corresponding to the frequency of the external noise, and uses a rotation speed signal higher than the predetermined rotation speed. A vehicle control device for controlling a vehicle. 2. The vehicle control device according to claim 1, wherein the predetermined rotation speed is determined according to a frequency of a heater AC current of a road surface heater. 3. The vehicle control device according to claim 1, wherein the control target is an automatic clutch device that automatically controls a clutch that connects an engine and a transmission, and the magnetic rotational speed sensor includes: A vehicle control device, which is a sensor that detects an input rotation speed from a clutch to a transmission. 4. The vehicle control device according to claim 1, wherein the noise determination unit determines that the detection target of the magnetic rotational speed sensor is not rotating when the detection target is not rotating. A vehicle control device, wherein when a magnetic rotation speed sensor detects a rotation speed signal indicating that the vehicle is rotating, it is determined that external noise is included in the rotation speed signal.