JP2003226149A - Drive control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely judge the gear range of a transfer device even in the failure of a sensor for detecting the gear position at a drop of vehicle speed. <P>SOLUTION: This control device 700 comprises a circuit for judging the gear position of the transfer device 400 on the basis of a signal received from the Lo range switch 500 of the transfer device 400; a circuit for judging the gear state of the transfer device 400 on the basis of the ratio of input and output rotating speeds calculated from the rotating speeds detected by a first rotating speed sensor 600 and a second rotating speed sensor 650; a circuit for storing the gear position and gear state at a predetermined sampling time; and a circuit for judging the present gear range on the basis of either one of the gear state and gear position stored one sampling time before when a four-wheel drive vehicle is changed from a general traveling state to a predetermined vehicle speed or less, and the gear state and gear position are not mutually matched. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive control device for a vehicle, and more particularly to a drive control device for a vehicle provided with an auxiliary transmission device called a transfer device.

[0002]

2. Description of the Related Art In order to improve stability when driving on rough roads,
There are vehicles equipped with a transfer device that travels by changing the driving state and driving force of the vehicle by manual switching as necessary, for example, a part-time 4WD type vehicle and a full-time 4WD type vehicle.

The traveling control of the vehicle is performed depending on whether the transmission gear of such a transfer device is a Hi gear or a Lo gear. The transfer device is provided with a sensor for detecting that the transmission gear of the transfer device is a Lo gear. Various vehicle controls are executed based on the detection result of this sensor.

For example, when this sensor is disconnected, it is determined that the Lo gear is not actually the Lo gear (that is, the Hi gear) although it is actually the Lo gear. As described above, when the control is performed as the Hi gear when the Lo gear is actually in the state, the following problems occur.

In the low speed running mode using the Lo gear, the rate of change in rotation of the automatic transmission is large, so the rate of change in rotation generated in the drive system after the automatic transmission is large. On the other hand, based on the determination that it is a Hi gear, the vehicle
The control adapted to the high speed driving mode by the Hi gear is performed. Therefore, the high-speed traveling mode may not be able to cope with a large rotation change rate. Furthermore, the input torque to the power transmission mechanism after the transfer device increases,
Especially in a stall state where the torque amplifying effect of the torque converter is large, the strength of the power transmission mechanism is exceeded, and there is a possibility of damage.

Further, when this sensor is short-circuited, it is judged to be the Lo gear although it is actually the Hi gear. As described above, when the control is performed as the Lo gear when the gear is actually in the Hi gear, the following problems occur.

On the basis of the determination that the vehicle is in the Lo gear, the control adapted to the low speed traveling mode by the Lo gear is performed. In the low speed traveling mode, control such as restriction of shifting of the automatic transmission (for example, OD (Over Drive) not entered) is performed. In this case, actually H
Since the i-gear is used, there is a problem in running that the shift stage of the automatic transmission does not reach OD even if the vehicle speed increases.

Japanese Unexamined Patent Publication No. 8-91076 discloses a device for diagnosing an abnormality of a sensor for detecting the gear position of such a transfer device. The transfer device disclosed in this publication has a rotation speed sensor for detecting the input side rotation speed of the transfer device, a rotation speed sensor for detecting the output side rotation speed of the transfer device, and a Lo gear of the transfer device as the output side rotation speed. A calculation circuit for calculating the input side estimated rotation speed from the value multiplied by the ratio, a judgment circuit for judging the gear state of the transfer device by comparing the input side estimated rotation speed and the input side rotation speed, and the result of this judgment. And a diagnostic circuit for diagnosing an abnormality of each sensor by determining the coincidence with the detection signals of the Hi gear position sensor and the Lo gear position sensor.

According to the device disclosed in this publication, when the vehicle is running, the calculating circuit calculates the input side estimated rotation speed, and the judging circuit judges the gear state (Hi gear, Lo gear) of the transfer device. . The diagnostic circuit is
Based on the determination result and the detection signal of the gear position sensor, the abnormality of the sensor is diagnosed. As a result, the abnormality of the gear position sensor can be easily detected.

[0010]

However, in the transfer device disclosed in the above-mentioned publication, the gear state of the transfer device is determined based on the input speed to the transfer device and the output speed from the transfer device. . For this reason, when the vehicle is in a state close to a stop or in a stopped state, the rotation speed cannot be detected, so that the state of the transfer device cannot be determined and the abnormality of the gear position sensor cannot be detected. Further, if the sensor for detecting that the transmission gear is the Lo gear and the sensor for detecting that the transmission gear is the Hi gear are attached to the transfer device, the cost increases. Further, even if the two sensors are attached in this way, if the two sensors simultaneously become abnormal (disconnection or short circuit), the above-mentioned problems occur.

The present invention has been made to solve the above-mentioned problems, and it is possible to accurately grasp the gear state of the transfer device even when the vehicle is traveling at a low speed or is stopped. A drive control device for a vehicle is provided. Further, the present invention is to provide a drive control device for a vehicle, which can accurately grasp the gear state of the transfer device even if the sensor for detecting the gear position is out of order.

[0012]

A drive control device for a vehicle according to a first aspect of the invention is based on a rotation speed input to a transfer device and a rotation speed output from the transfer device at a predetermined sampling time. A determination means for determining the gear state of the transfer device, a switching means for manually switching the gear, a detection means for detecting the gear position of the transfer device at a predetermined sampling time, and a determination means. Based on the detected gear state and the detected gear position, abnormality detection means for detecting abnormality of the detection means, the determined gear state, the detected gear position, and information indicating the abnormality of the detection means are displayed. When the storage unit for storing and the determination unit can determine the gear state, the determination unit cannot determine the gear state based on the stored gear state. If the determination means cannot determine the gear state based on the stored gear position, the information indicating the abnormality of the detection means is stored if the information indicating the abnormality of the detection means is not stored. In this case, the processing means for judging the gear of the transfer device based on either the gear position or the gear state stored in the storage means one sampling time before and storing it in the storage means. Including.

According to the first aspect of the invention, the gear state based on the input / output speed of the transfer device determined by the determination means and the gear position detected by the detection means are stored at a predetermined sampling time. Stored in the means. Further, the storage means stores information indicating an abnormality of the detection means when the gear state and the gear position do not match. If the gear state of the transfer device can be determined by the determining means such as the ratio of the input / output rotation speed when the vehicle is traveling normally, the gear of the transfer device is determined based on the determined gear state and stored in the storage means. Remembered. The gear position detected when the gear state of the transfer device cannot be determined by the determination means such as the ratio of the input / output rotation speed when the vehicle is traveling at low speed and the information indicating the abnormality of the detection means is not stored. Based on the above, the gear of the transfer device is determined and stored in the storage means. If the information indicating the abnormality of the detecting means is stored when the vehicle is shifted from the normal traveling to the low speed traveling, the gear state and the detecting means determined by the determining means during the normal traveling stored in the storing means are abnormal. The gear of the transfer device is determined based on any one of the gear positions detected before becoming, and is stored in the storage means. As a result, even when the gear state of the transfer device cannot be determined by the ratio of the input / output speed of the transfer device, and the gear position of the transfer device cannot be detected normally due to an abnormality in the sensor that detects the gear position of the transfer device, The gear of the transfer device that is correctly grasped before the sampling time is determined to be the current gear of the transfer device. As a result, a drive control device for a vehicle that can accurately grasp the gear state of the transfer device even when the vehicle is running at low speed or is stopped and the sensor that detects the gear position is out of order can do.

A drive control device for a vehicle according to a second aspect of the present invention,
In addition to the configuration of the first invention, a vehicle speed detecting means for detecting the vehicle speed of the vehicle is further included. The processing means includes means for determining that the determination means cannot determine the gear state when the vehicle speed is equal to or lower than a predetermined value.

According to the second aspect of the invention, when the vehicle is running at a low speed or is stopped, it is judged that the gear state of the transfer device cannot be judged by the ratio of the input / output speed of the transfer device. The current gear can be determined based on either the gear state or the gear position stored in the storage means before the sampling time.

A drive control device for a vehicle according to a third aspect of the present invention,
In addition to the configuration of the first or second aspect of the invention, it further includes detection means for detecting an abnormality in the rotation speed sensor that detects the rotation speed input to the transfer device and the rotation speed output from the transfer device. The processing means includes means for determining that the determination means cannot determine the gear state when the detection means detects an abnormality of the rotation speed sensor.

According to the third aspect of the invention, when it is detected that the rotation speed sensor for detecting the rotation speed input to the transfer device and the rotation speed output from the transfer device is abnormal, the input / output rotation of the transfer device is detected. It is determined that the gear state of the transfer device cannot be determined by the ratio of the numbers, and the current gear can be determined based on either the gear state or the gear position stored in the storage unit one sampling time before.

A drive control device for a vehicle according to a fourth invention is
In addition to the configuration of the third aspect of the invention, if the detecting means does not detect either the rotation speed input to the transfer device or the rotation speed output from the transfer device when the transfer device is not in the neutral position, the rotation speed is detected. It includes means for detecting sensor malfunctions.

According to the fourth aspect of the invention, when the transfer device is not in the neutral position, the rotation speed sensor must detect either the rotation speed input to the transfer device or the rotation speed output from the transfer device. The abnormality of the sensor can be detected, and it is determined that the gear state of the transfer device cannot be determined based on the ratio of the input / output speed of the transfer device, and based on either the gear state or the gear position stored in the storage means one sampling time ago. You can judge the current gear.

A drive control system for a vehicle according to a fifth aspect of the invention is
In addition to the configuration of any one of the first to fourth aspects of the invention, it is a device for switching between a low speed gear and a high speed gear. The determining means is means for determining whether the gear state of the transfer device is a low speed gear or a high speed gear, based on the ratio of the rotational speed input to the transfer device and the rotational speed output from the transfer device. including. The detection means includes means for detecting whether the gear position of the transfer device is a low speed gear or a high speed gear. The abnormality detecting means includes means for detecting an abnormality of the detecting means when the determined gear state and the detected gear position do not match.

According to the fifth aspect of the invention, in the transfer device for switching between the high speed gear and the low speed gear, it is determined whether the gear state is the low speed gear or the high speed gear based on the ratio of the input / output speed of the transfer device. Then, it is detected whether the gear position of the transfer device is the low speed gear or the high speed gear. If the gear position is detected as a high speed gear regardless of whether the gear state is determined as a low speed gear, the gear position is a low speed gear regardless of whether the gear state is determined as a high speed gear. When it is detected that the abnormality of the detection means is detected.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

A driving force transmission device including a transfer device according to an embodiment of the present invention will be described below. In the following description, it is assumed that the driving force transmission device is mounted on a four-wheel drive vehicle.

Referring to FIG. 1, this driving force transmitting device is
Engine 100, torque converter 200, automatic transmission 300, transfer device 400 provided on the output side of automatic transmission 300, and transfer device 40
The Lo range switch 500 that detects that 0 is the Lo gear position, the first rotation speed sensor 600 that detects the input rotation speed to the transfer device 400, and the second rotation speed sensor that detects the output rotation speed from the transfer device 400. Rotation speed sensor 650 and a control device 700 for controlling the transfer device 400 and the like. The driving force output from the transfer device 400 is transmitted to the front wheels and the rear wheels via the front propeller shaft and the rear propeller shaft, respectively.

The transfer device 400 is also called an auxiliary transmission, and has a Lo gear that further reduces the driving force output from the automatic transmission 300. The Lo range switch 500 transmits to the control device 700 a signal indicating that the gear position is on the Lo side. First rotation speed sensor 6
00 is the input speed SP to the transfer device 400
(1) is transmitted to the control device 700. The second rotation speed sensor 650 transmits the output rotation speed SP (2) from the transfer device 400 to the control device 700. Further, the vehicle speed of the four-wheel drive vehicle is input to the control device 700 from the vehicle speed sensor.

The control device 700 has a memory inside. When the control device 700 receives the Lo range signal from the Lo range switch 500 at a predetermined sampling time, the control device 700 determines that the gear position is in the Lo state and stores it in the memory inside the control device 700. When the Lo range signal is not received from the Lo range switch 500, the gear position is determined to be in the Hi state and stored in the memory inside the control device 700. The gear position determined based on the signal received from the Lo range switch is stored in the memory at each sampling time.

The control device 700 includes the first rotation speed sensor 6
The ratio η = [SP (1) / SP (2)] between the input rotation speed SP (1) received from 00 and the output rotation speed SP (2) received from the second rotation speed sensor 650 is calculated. At this time, it is necessary that the vehicle speed is equal to or higher than a predetermined speed, and that both rotation speed sensors 600 and 650 are not abnormal. This ratio η is a predetermined L
If it is in the o gear range, the actual gear state is determined to be the Lo state and stored in the memory inside the control device. This ratio η
Is within a predetermined Hi gear range, the actual gear state is determined to be the Hi state and stored in the memory inside the control device. The actual gear state determined based on such a rotation speed ratio is stored in the memory at each sampling time.

The control device 700 includes a transfer device 40.
Judge the 0 gear. At this time, if the vehicle speed is equal to or higher than the predetermined speed and the rotation speed sensors 600 and 650 are not abnormal, based on the gear state stored in the memory,
The current gear of transfer device 400 is determined. If the vehicle speed is equal to or lower than a predetermined speed, or if one of the first rotation speed sensor 600 and the second rotation speed sensor 650 is abnormal and the Lo range switch is not abnormal, it is stored in the memory. The current gear of the transfer device 400 is determined based on the gear position. If the vehicle speed is equal to or lower than a predetermined speed, or if one of the first rotation speed sensor 600 and the second rotation speed sensor 650 is abnormal and the Lo range switch is abnormal,
The current gear of the transfer device 400 is determined based on either the gear state or the gear position stored in the memory one sampling time ago.

On the basis of the gears of the transfer device 400 thus determined, the traveling control of the four-wheel drive vehicle is performed.

Referring to FIG. 2, the program executed by control device 700 of the driving force transmission device according to the present embodiment has the following control structure regarding the transfer state determination process.

Step (hereinafter, step is abbreviated as S)
At 100, control device 700 determines whether the sampling time has been reached. When the sampling time has come (YES in S100), the process proceeds to S110. If not (NO in S100), the process proceeds to S
It is returned to 100 and waits until the sampling time is reached.

At S110, control device 700 determines whether first rotation speed sensor 600 and second rotation speed sensor 650 are normal. When the transfer device 400 is not in the N range, this determination is made because the first rotation speed sensor 600 and the second rotation speed sensor 650 both detect the rotation speed. When the transfer device 400 is not in the N range and either the first rotation speed sensor 600 or the second rotation speed sensor 650 detects the rotation speed as 0, it is determined that the rotation speed sensor is abnormal. If the rotation speed sensor is normal (YES in S110), the process proceeds to S120. If not (NO in S110), the process is S
Moved to 170.

At S120, control device 700 determines, based on the vehicle speed received from the vehicle speed sensor, whether or not the current vehicle speed is equal to or higher than a predetermined speed. If the vehicle speed is equal to or higher than the predetermined speed (YES in S120)
S), the process proceeds to S130. If not (NO in S120), the process proceeds to S170.

At S130, control device 700 causes αL <
It is determined whether SP (1) / SP (2) <βL. Here, α and β are coefficients. L is the gear ratio of the Lo gear. That is, in the processing in S130, the ratio η between the rotation speed input to the transfer device 400 and the rotation speed output from the transfer device 400 is between the lower limit value and the upper limit value for determining the transfer state as the Lo state. Or not. αL <S
If P (1) / SP (2) <βL (Y at S130
ES), and the process proceeds to S150. If not (NO in S130), the process proceeds to S140.

At S140, control device 700 causes γH <
It is determined whether SP (1) / SP (2) <δH. The determination in S140 is similar to the determination in S130 described above, the ratio η between the input rotation speed to the transfer device 400 and the output rotation speed from the transfer device 400.
, It is determined whether the transfer state is between the lower limit value and the upper limit value for determining the Hi state. γH <S
If P (1) / SP (2) <δH (YES in S140), the process proceeds to S160. If not (NO in S140), the process proceeds to S170.

At S150, control device 700 stores in its internal memory that the actual state of the transfer device is the Lo state. At S160, control device 700
In its internal memory, the actual state of the transfer device is H
Memorize that it is in the i state. At S170, the control device 70
0 stores in its internal memory that the actual state of the transfer device is indefinite.

In the flowchart shown in FIG. 2, these processes are executed at each predetermined sampling time, and the executed results are stored in the internal memory of the control device 700. At this time, the data stored in the memory one sampling time before is overwritten and stored.

Referring to FIG. 3, the program executed by control device 700 of the driving force transmission device according to the present embodiment has the following control structure regarding the Lo range switch failure detection process.

At S200, control device 700 determines whether or not the sampling time has been reached. When the sampling time is reached (YES in S200), the process proceeds to S210. If not (NO in S200), the process returns to S200 and waits for the sampling time.

At S210, control device 700 reads the actual state of the transfer device stored in the internal memory of storage device 700. The actual state of the transfer device is the state determined by the transfer state determination process of FIG.

At S220, control device 700 determines whether or not the actual state of the transfer device is indefinite. If the actual state of the transfer device is indeterminate (YES in S220), this Lo range switch failure detection process is terminated and the process returns to S200. If not (NO in S220), the process proceeds to S230.

At S230, control device 700 determines whether the actual state of transfer device 400 is the Lo state. The actual state of the transfer device 400 is L
If it is in the o state (YES in S230), the process proceeds to S24.
Moved to 0. If not (N in S230, N
O), the process proceeds to S250.

At S240, control device 700 determines whether or not the Lo range switch is in the on state. This determination is made based on whether or not a signal is received from the Lo range switch 500. If the Lo range switch is on (YES in S240), the process proceeds to S26.
Moved to 0. If not (N in S240, N
O), the process proceeds to S270.

At S250, control device 700 determines whether the Lo range switch is off. Lo
If the range switch is off (YES in S250)
S), the process proceeds to S260. If not (NO in S250), the process proceeds to S270.

At S260, control device 700 stores in the internal memory of control device 700 that the state of the Lo range switch is normal. At S270, control device 700
Stores in the internal memory of the control device 700 that the state of the Lo range switch is a failure state.

In the flow chart shown in FIG. 3, these processes are executed at predetermined sampling times, and the execution results are stored in the internal memory of the control device 700. At this time, the data stored in the memory one sampling time before is overwritten and stored.

Referring to FIG. 4, the program executed by control device 700 of the driving force transmission device according to the present embodiment has the following control structure regarding the transfer Hi / Lo determination process.

At S300, control device 700 determines whether or not the sampling time has been reached. When the sampling time is reached (YES in S300), the process proceeds to S310. If not (NO in S300), the process returns to S300 and waits until the sampling time is reached.

At S310, control device 700 reads the actual state of the transfer device stored in the internal memory of control device 700.

At S320, control device 700 determines whether the actual state of the transfer device is an undefined state. If the actual state of the transfer device is indeterminate (YES in S320), the process proceeds to S340. If not (NO in S320), the process proceeds to S
Moved to 330.

At S330, control device 700 determines whether or not the actual state of the transfer device is the Lo state. If the actual state of the transfer device is the Lo state (YES in S330), the process proceeds to S370. If not (NO in S330), the process is S
Moved to 380.

At S340, control device 700 reads the state of the Lo range switch stored in the internal memory of control device 700.

At S350, control device 700 determines whether the Lo range switch is in a normal state. This determination is made based on the state of the Lo range switch read in S340. If the Lo range switch is normal (YES in S350), the process proceeds to S360.
Is moved to. If not (NO in S350),
The transfer device Hi / Lo determination process is completed, and the process returns to S300.

At S360, control device 700 determines whether the Lo range switch is in the on state. Lo
If the range switch is on (YES in S360), the process proceeds to S370. If not (NO at S360), the process proceeds to S380.

At S370, control device 700 determines that the transfer device is in the Lo range and stores it in the internal memory of control device 700. At S380, control device 700
, The transfer device determines that it is in the Hi range and stores it in the internal memory of the control device 700. After that, the process is S3.
When it is returned to 00 and the next sampling time comes, the above-described processing of S310 to S380 is repeated.

The operation of the driving force transmission device including the transfer device according to the present embodiment based on the control structure and the flowchart as described above will be described.

<During Normal Running and Normal Rotational Speed Sensor> When the four-wheel drive vehicle is traveling at a speed equal to or higher than a predetermined speed, the first rotational speed sensor 600 and the second rotational speed sensor 650 are used. The case where is normal will be described. When the sampling time for transfer status judgment comes (S
If YES at 100, the first rotation speed sensor 600 and the second rotation speed sensor 650 are normal (S110).
YES), the vehicle speed is determined. Since the vehicle speed is equal to or higher than the predetermined speed (YES in S120), the ratio (η = SP) between the input rotation speed SP (1) to the transfer device 400 and the output rotation speed SP (2) to the transfer device 400. It is determined whether (1) / SP (2)) is between the lower limit value and the upper limit value of the rotation speed determined as the Lo gear (S130). When the rotation speed ratio is between the lower limit value and the upper limit value of the Lo range (YES in S130), the actual state of the transfer device is stored in the memory as the Lo state (S150). When the rotation speed ratio η is between the lower limit value and the upper limit value at which the gear state is determined to be the Hi state (YES in S140), the actual state of the transfer device is stored in the memory as the Hi state. Remembered.

When the sampling time for the transfer Hi / Lo determination process comes (YES in S300), the actual state of the transfer device stored in the memory is read (S310). Since the actual state of the transfer device is not an indefinite state (NO in S320), it is determined whether the actual state of the transfer device is the Lo state (S330). The actual state of the transfer device is Lo
If it is in the state (YES in S330), the transfer device is stored in the memory as the Lo range (S37).
0). If the actual state of the transfer device is not the Lo state (NO in S330), the transfer device is in the H state.
The i-range is stored in the memory (S380).

<When the four-wheel drive vehicle is running at a low speed and the Lo range switch is normal> Below, when the four-wheel drive vehicle is running at a vehicle speed slower than a predetermined speed (including a case where the vehicle is stopped). ), And the operation when the Lo range switch 500 is normal will be described.

When the sampling time for the Lo range switch failure detection processing comes (YES in S200), the actual state of the transfer device stored in the memory is read (S210). Since the actual state of the transfer device is not an indefinite state (NO in S220), it is determined whether the actual state of the transfer device is the Lo state (S230). The actual state of the transfer device is Lo
If it is in the state (YES in S230) and the Lo range switch is not in the on state (NO in S240), the state of the Lo range switch 500 is stored in the memory as a failure (S270). Also, if the actual state of the transfer device is not the Lo state (NO in S230) and the Lo range switch is not in the OFF state (N in S250).
O), similarly, the state of the Lo range switch 500 is stored in the memory as a failure (S270). Furthermore, if the actual state of the transfer device is the Lo state (S2
If the Lo range switch is in the on state (YES in S240), the Lo range switch 50
The state of 0 is stored in the memory as normal (S26
0). Further, if the actual state of the transfer device is not the Lo state (NO in S230) and the Lo range switch is in the OFF state (YES in S250), the state of the Lo range switch is stored in the memory as normal. (S260).

When the sampling time of the transfer Hi / Lo determination processing comes (YES in S300), the stored actual state of the transfer device is read.
The actual state of the transfer device is that the vehicle speed of the four-wheel drive vehicle is not equal to or higher than a predetermined speed (N in S120
O), it is determined that the state is indefinite (Y in S320).
S). The state of the Lo range switch stored in the memory is read to determine whether the Lo range switch is in the normal state. Since the Lo range switch is in the normal state (YES in S350), it is determined whether or not the Lo range switch is in the on state. If the Lo range switch is on (YES in S360), the transfer device is stored in the memory even if it is determined to be in the Lo range (S370). If the Lo range switch is not on (NO in S370), the transfer device is set to H
The i-range is determined and stored in the memory (S38
0).

<When the four-wheel drive vehicle is traveling at a low speed and the Lo range switch is abnormal> Below, the four-wheel drive vehicle is traveling at a vehicle speed lower than the predetermined speed from the state of traveling at a predetermined speed. An operation when the Lo range switch 500 is in a normal state (including a case of stopping) and the Lo range switch 500 is not normal will be described.

When the sampling time for the transfer Hi / Lo determination processing comes (YES in S300), the stored actual state of the transfer device is read (S310). Since the actual state of the transfer device is indefinite (YES in S320), the state of the Lo range switch stored in the memory is read (S3).
40). The Lo range switch is not normal (S35
(NO at 0), the transfer Hi / Lo determination process ends this operation without rewriting the range of the transfer device 400 stored in the internal memory of the control device 700. That is, the state in which the range of the transfer device 400 determined at the previous sampling time is stored in the internal memory of the control device 700 is held.

As described above, according to the transfer device of the present embodiment, the gear state of the transfer device can be determined by the ratio of the input / output speed to / from the transfer device while the four-wheel drive vehicle is traveling normally. Determines the gear of the transfer device based on the determined gear state. If the gear state of the transfer device cannot be determined based on the ratio of the input / output speeds when the four-wheel drive vehicle is running at low speed, and the Lo range switch is normal, the gear position detected by the Lo range switch is detected. Based on, the gear of the transfer device is determined. When the four-wheel drive vehicle shifts from the normal running to the low speed running, if the Lo range switch is abnormal, the determination of the gear state based on the ratio of the number of rotations and the determination of the gear position by the Lo range switch are not accurate. The gear position of the transfer device is determined based on either the gear state or the gear position stored during traveling.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[Brief description of drawings]

FIG. 1 is a control block diagram of a driving force transmission device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a control structure of transfer state determination processing executed in the embodiment of the present invention.

FIG. 3 is Lo implemented in an embodiment of the present invention.
It is a flow chart which shows the control structure of range switch failure detection processing.

FIG. 4 is a flowchart showing a control structure of transfer Hi / Lo determination processing executed in the embodiment of the present invention.

[Explanation of symbols]

100 engine, 200 torque converter, 300
Automatic transmission, 400 Transfer device, 500
Input side rotation speed detection sensor, 600 output side rotation speed detection sensor, 700 control device.

Claims (5)

[Claims] 1. At a predetermined sampling time,
Determination means for determining the gear state of the transfer device based on the number of revolutions input to the transfer device and the number of revolutions output from the transfer device; switching means for manually changing the gear; A detection unit for detecting the gear position of the transfer device at a predetermined sampling time, and an abnormality for detecting an abnormality of the detection unit based on the determined gear state and the detected gear position. A detection unit, the determined gear state, the detected gear position,
When the storage unit for storing the information indicating the abnormality of the detection unit and the determination unit can determine the gear state, the determination unit cannot determine the gear state based on the stored gear state. In this case, if the information indicating the abnormality of the detection means is not stored, the abnormality of the detection means is detected even if the determination means cannot determine the gear state based on the stored gear position. If the information to be stored is stored, the gear of the transfer device is determined based on either the gear position or the gear state stored in the storage means one sampling time before and stored in the storage means. A drive control device for a vehicle, comprising: 2. The drive control device for the vehicle further includes a vehicle speed detecting means for detecting a vehicle speed of the vehicle, and the processing means is characterized in that the determining means determines that the vehicle speed is equal to or less than a predetermined value. The drive control device for a vehicle according to claim 1, further comprising means for determining that the gear state cannot be determined. 3. The drive control device for the vehicle further includes a detection unit for detecting an abnormality of a rotation speed sensor that detects a rotation speed input to the transfer device and a rotation speed output from the transfer device. 3. The method according to claim 1, wherein the processing means includes means for determining that the determination means cannot determine the gear state when the detection means detects an abnormality in the rotation speed sensor. Vehicle drive control device. 4. The number of revolutions if the detecting means does not detect either one of the number of revolutions input to the transfer device or the number of revolutions output from the transfer device when the transfer device is not in the neutral position. The vehicle drive control device according to claim 3, further comprising means for detecting an abnormality of the sensor. 5. The transfer device is a device for switching between a low speed gear and a high speed gear, and the determining means determines a ratio between a rotation speed input to the transfer device and a rotation speed output from the transfer device. The transfer device includes a means for determining whether the gear state of the transfer device is a low speed gear or a high speed gear, and the detection means is a low speed gear or a high speed gear. Including a means for detecting whether, the abnormality detection means, when the determined gear state and the detected gear position does not match, including a means for detecting an abnormality of the detection means, The drive control device for a vehicle according to claim 1.