JP2013221440A - Atmospheric pressure sensor failure detection device for control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an atmospheric pressure sensor failure detection device in which control support can be continued even under an atmospheric pressure sensor failure by highly accurately detecting the failure of an atmospheric pressure sensor at a low cost, in a control device for a vehicle which performs control support on a controlled part based on an atmospheric pressure detected by the atmospheric pressure sensor.SOLUTION: An atmospheric pressure sensor failure detection device includes: an atmospheric pressure sensor 51; an atmospheric pressure detection section 49; an altitude difference computation section 53, a mileage detection section 54; a first estimated road surface gradient computation section 55 which computes the first estimated road surface gradient θp of a road surface based on an altitude difference Δh and a mileage D between two points; an acceleration sensor 52; an acceleration detection section 56; a second estimated road surface gradient computation section 57 which computes a second estimated road surface gradient θg based on component force α of detected gravity acceleration; an atmospheric pressure sensor failure determination section 58 which determines whether the atmospheric pressure sensor 51 is failed or normal based on a gradient difference Δθ between the first estimated road surface gradient θp and the second estimated road surface gradient θg; and a road surface gradient selection section 59 which selects either the first estimated road surface gradient θp or the second estimated road surface gradient θg as a road surface gradient in controlling a controlled part 30.

Description

  The present invention relates to an atmospheric pressure sensor failure detection device for a vehicle control device that supports control of a brake device, a transmission device, an engine, and the like, which are controlled parts, based on an atmospheric pressure detected by an atmospheric pressure sensor mounted on the vehicle. About.

Conventionally, when a vehicle travels, an atmospheric pressure is detected by an atmospheric pressure sensor, and based on the detected atmospheric pressure, a control device provides control assistance for engine control, brake control, shift control, and the like. There is what is shown in Document 2. The one shown in Patent Document 1 has two atmospheric pressure sensors. One is a main sensor, and the other is a backup spare sensor. Then, the estimated atmospheric pressure PAcal is calculated from the pressure data acquired by the manifold pressure sensor, engine speed, throttle opening data, and the like. Thereafter, when the difference between the atmospheric pressure data PAa and PAb output from the main sensor and the spare sensor exceeds a predetermined value, the sensor having the larger difference from the estimated atmospheric pressure PAcal among the atmospheric pressure data PAa or PAb is selected. It is determined that there is a failure, and the subsequent control is continued based on the detected data of the sensor.
The one shown in Patent Document 2 has only one atmospheric pressure sensor. Then, the past data and the latest data of the atmospheric pressure sensor are continuously compared, and when the amount of change becomes a predetermined value or more, it is determined that an abnormality has occurred in the atmospheric pressure sensor. When it is determined that an abnormality has occurred, the atmospheric pressure data for control support is replaced with backup data and control is continued. The backup data may be the latest data or the average value among the data determined to be normal among the past data, or may be a preset fixed value.

JP 2006-226136 A JP-A-6-201496

  However, in the prior art disclosed in Patent Document 1, two atmospheric pressure sensors are required, and a manifold pressure sensor and a plurality of other data are necessary to calculate the estimated atmospheric pressure PAcal. The load on the system increases and the cost increases, and it is not versatile to be installed in an existing system. In the prior art disclosed in Patent Document 2, since there is only one atmospheric pressure sensor and the determination is based on the rate of change of the output value from the past data of the atmospheric pressure sensor, a certain abnormal value is output. It is difficult to detect an abnormality in a failure mode that continues.

  The present invention has been made in view of the above points. In a vehicle control apparatus that supports and controls a controlled portion based on atmospheric pressure detected by an atmospheric pressure sensor, a failure of the atmospheric pressure sensor can be detected with high accuracy at low cost. An object of the present invention is to provide an atmospheric pressure sensor failure detection device that detects and can continue control support even when an atmospheric pressure sensor failure occurs.

  In order to achieve the above object, the invention of the atmospheric pressure sensor failure detection device for a vehicle control device according to claim 1 includes a vehicle control unit for controlling the operation of the controlled portion of the vehicle based on the gradient of the road surface. An atmospheric pressure sensor failure detection device for a vehicle control device, comprising: an atmospheric pressure sensor mounted on the vehicle; an atmospheric pressure detection unit for detecting atmospheric pressure by the atmospheric pressure sensor; and a travel distance of the vehicle. A travel distance detection unit, an altitude difference calculation unit that calculates an altitude difference based on an atmospheric pressure difference between two points separated by a predetermined distance in a running vehicle detected by the atmospheric pressure detection unit, and an altitude between the two points A first estimated road surface gradient calculating unit that calculates a first estimated road surface gradient of the road surface based on the difference and the travel distance between the two points separated by the predetermined distance detected by the travel distance detecting unit, and mounted on the vehicle Acceleration sensor An acceleration detector that detects a gravitational acceleration component perpendicular to the road surface by the acceleration sensor; a second estimated road gradient calculator that calculates a second estimated road gradient based on the detected gravitational force component; In the atmospheric pressure sensor failure determination unit that compares the difference between the first estimated road surface gradient and the second estimated road surface gradient and a predetermined reference value to determine whether the failure is normal or not, When the atmospheric pressure sensor is determined to be normal, the vehicle control unit determines the first estimated road gradient, and when the atmospheric pressure sensor is determined to be malfunctioning, the second estimated road gradient. A road surface gradient selecting unit that sets a road surface gradient when controlling the controlled unit.

  In the invention of the atmospheric pressure sensor failure detection device of the vehicle control device according to claim 2, the atmospheric pressure at the time of stop immediately before the ignition of the vehicle detected by the atmospheric pressure detection unit is stored in claim 1. A stop-time atmospheric pressure storage unit, a startup-time atmospheric pressure acquisition unit that acquires a startup-time atmospheric pressure detected by the atmospheric pressure detection unit when the ignition is first turned on after the ignition is turned off; A reference value change control unit that compares the atmospheric pressure at stop and the atmospheric pressure at start-up and changes the predetermined reference value of the atmospheric pressure sensor failure determination unit according to a difference between the two.

  In the invention of the atmospheric pressure sensor failure detection device of the vehicle control device according to claim 3, in claim 2, the start-up atmospheric pressure is the stoppage of the predetermined reference value changed by the reference value change control unit. When the pressure is smaller than the atmospheric pressure, the direction is changed so that the failure is easily determined.

  According to the first aspect, the first estimated road surface gradient of the road surface calculated using the output value of the atmospheric pressure sensor and the second estimated road surface gradient calculated based on the output value of the acceleration sensor are compared. Then, the difference between the two and a predetermined reference value are compared to determine whether the atmospheric pressure sensor is normal or malfunctioning. When it is determined that the atmospheric pressure sensor is normal, the first estimated road surface gradient is obtained. When it is determined that the atmospheric pressure sensor is malfunctioning, the second estimated road surface gradient is obtained. The road surface gradient is a parameter for control. As a result, even if the atmospheric pressure sensor breaks down, the control support can be preferably continued using the detection data of the acceleration sensor. In addition, if only one atmospheric pressure sensor and acceleration sensor are provided, control support can be provided, so that it can be realized at low cost.

  According to claim 2, the stop atmospheric pressure immediately before the ignition is turned off is compared with the startup atmospheric pressure detected by the atmospheric pressure detection unit when the ignition is first turned on after the ignition is turned off. To do. Then, the reference value change control unit changes the predetermined reference value of the atmospheric pressure sensor failure determination unit according to the difference between the two. As a result, it is possible to satisfactorily cope with the movement of the atmospheric pressure due to changes in the weather, and it is possible to accurately determine the failure of the atmospheric pressure sensor.

  According to the third aspect, the predetermined reference value to be changed by the reference value change control unit is that when the starting atmospheric pressure is smaller than the stopping atmospheric pressure, that is, when the low pressure arrives at the vehicle stopping place, When it is predicted that the atmospheric pressure sensor has become stable, the atmospheric pressure sensor is changed in a direction in which a failure is easily determined according to the difference between the atmospheric pressure at startup and the atmospheric pressure at stop. Thereby, when the atmospheric pressure is unstable, the atmospheric pressure sensor is controlled not to be used actively, and the reliability of control support is improved.

It is the figure which showed typically the structure of the vehicle which concerns on embodiment of this invention. It is the block diagram which showed typically the structure of the control apparatus for vehicles which concerns on embodiment of this invention. It is the figure which showed the height difference (DELTA) h and road surface gradient (theta) estimated in the control apparatus for vehicles which concerns on embodiment of this invention. It is the flowchart 1 which concerns on 1st Embodiment. It is the flowchart 2 which concerns on 2nd Embodiment. 10 is a characteristic graph (map) of ΔPc−reference value Tv according to the second embodiment.

Hereinafter, a first embodiment of a vehicle M including a vehicle control device 1 having an atmospheric pressure sensor failure detection device 50 according to the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing an example of the configuration of the vehicle M. This vehicle M is a front-wheel drive (FF) vehicle, and is of a type in which the driving force of the engine 11 as a drive source mounted on the front of the vehicle body is transmitted to the front wheels Wfl and Wfr via the automatic transmission 12. The vehicle M is not limited to a front-wheel drive vehicle, but may be a vehicle of another drive system, for example, a rear-wheel drive (FR) vehicle, a four-wheel drive (4WD) vehicle, or an electric motor as a drive source. It may be a hybrid vehicle or an electric vehicle driven only by an electric motor. Further, the automatic transmission 12 is a general AT (automatic transmission), and a gear shift is performed according to a command from the transmission ECU 27, and detailed description thereof is omitted.

  The vehicle M includes a drive system 10 that drives the vehicle M and a braking system 40 that brakes the vehicle M. The drive system 10 includes an engine 11, an automatic transmission 12, a differential 13, left and right drive shafts 14a and 14b, an accelerator pedal 15, an engine control ECU 16, and a transmission ECU 27. The driving force of the engine 11 is changed by the automatic transmission 12 (corresponding to the controlled portion 30 of the present invention), and transmitted to the left and right front wheels Wfl and Wfr, which are driving wheels, through the differential 13 and the left and right drive shafts 14a and 14b. It has come to be. The engine 11 includes an intake pipe 17 through which air flows into the combustion chamber of the engine 11, and the amount of air passing through the intake pipe 17 is adjusted in the intake pipe 17 by adjusting the opening / closing amount of the intake pipe 17. A throttle valve 18 is provided.

  The throttle valve 18 is driven based on the depression amount (operation amount) of the accelerator pedal 15 according to the driving request of the driver. Specifically, the motor Mt (corresponding to the controlled portion 30 of the present invention) is controlled according to the operation amount of the accelerator pedal 15 to adjust the opening degree of the throttle valve 18. The opening degree of the throttle valve 18 is acquired by the throttle valve opening degree sensor 18a and transmitted to the engine control ECU 16. The injector 19 (corresponding to the controlled portion 30 of the present invention) is driven based on a control signal from the engine control ECU 16, and the injector 19 (according to the present invention) according to the depression amount (operation amount) of the accelerator pedal 15. The fuel injection amount (corresponding to the controlled unit 30) is controlled. In this way, the engine speed (engine torque) in the engine 11 is controlled.

  The braking system 40 includes a hydraulic brake device that applies a hydraulic braking force to the wheels Wfl, Wfr, Wrl, Wrr to brake the vehicle M. This hydraulic brake device causes each wheel cylinder WCfl, WCfr, WCrl, WCrr to regulate the rotation of each wheel Wfl, Wfr, Wrl, Wrr and the intake negative pressure of the engine 11 to act on the diaphragm to act on the diaphragm. And a negative pressure booster 22 that is a booster that boosts (increases) the brake operation force generated by the stepping operation.

  Further, the hydraulic brake device generates a brake fluid (oil) of a hydraulic pressure (hydraulic pressure) that is a basic hydraulic pressure corresponding to a brake operating force (that is, an operating state of the brake pedal 21) boosted by the negative pressure booster 22. A master cylinder 23 for supplying to each wheel cylinder WCfl, WCfr, WCrl, WCrr, a reservoir tank 24 for storing brake fluid and replenishing the brake fluid to the master cylinder 23, a master cylinder 23 and each wheel cylinder WCfl, WCfr. , WCrl, WCrr, and a brake hydraulic pressure control device 25 that can be applied to a wheel to be controlled by forming a control hydraulic pressure regardless of the depression state of the brake pedal 21 (in the controlled portion 30 of the present invention). And a brake control ECU 26 that controls the brake fluid pressure control device 25. The brake pedal 21 includes a brake switch 21a that detects that the brake pedal 21 has been depressed.

  Each wheel cylinder WCfl, WCfr, WCrl, WCrr is provided in each caliper CLfl, CLfr, CLrl, CLrr, and accommodates a fluid-tightly sliding piston (not shown). When basic hydraulic pressure or control hydraulic pressure is supplied to each wheel cylinder WCfl, WCfr, WCrl, WCrr, each piston presses a pair of brake pads BPfl, BPfr, BPrl, BPrr, which are friction members, and each wheel Wfl, The disc rotors DRfl, DRfr, DRrl, DRrr, which are rotating members that rotate integrally with Wfr, Wrl, Wrr, are sandwiched from both sides to restrict the rotation. A friction brake is constituted by the brake pads BPfl, BPfr, BPrl, BPrr and the disc rotors DRfl, DRfr, DRrl, DRrr.

  In this embodiment, the disc type brake is adopted, but a drum type brake may be adopted. In this case, when basic hydraulic pressure or control hydraulic pressure is supplied to each wheel cylinder WCfl, WCfr, WCrl, WCrr, each piston presses (expands) a pair of brake shoes, and each wheel Wfl, Wfr, Wrl, Wrr. The brake drum abuts on the inner peripheral surface of the brake drum, and the rotation of the brake drum is restricted. The brake fluid pressure control device 25 is composed of an ABS, a pressure regulating reservoir, a pump, a motor, and the like and is generally well known, and thus detailed description thereof is omitted.

  In order to control the controlled part 30 (the automatic transmission 12, the brake fluid pressure control device 25, the motor Mt, the injector 19 and the like), the atmospheric pressure sensor failure detection device 50 of the vehicle control device 1 includes a vehicle control unit 64 (a gear change). The machine ECU 27, the brake control ECU 26, and the engine control ECU 16) are communicably connected to each other and transmit a command value to control the controlled unit 30. In the present embodiment, the automatic transmission 12, the hydraulic brake device, the motor Mt, the injector 19, and the like are exemplified as the controlled unit 30, but not limited to this, only one of the controlled unit 30 is controlled. Alternatively, a plurality may be arbitrarily selected and set as the controlled unit 30.

  Next, the vehicle control apparatus 1 according to the first embodiment including the atmospheric pressure sensor failure detection apparatus 50 according to the present invention will be described with reference to FIGS. 1 and 2. FIG. 2 is a block diagram schematically showing the configuration of the vehicle control device 1. The vehicle control device 1 includes an atmospheric pressure sensor failure detection device 50 (computer unit 3), a vehicle speed sensor 62, a distance meter 61, and a vehicle control unit 64 that are communicably connected to the atmospheric pressure sensor failure detection device 50. And the to-be-controlled part 30 is connected so that communication with the vehicle control part 64 is possible. The atmospheric pressure sensor failure detection device 50 includes a computer unit 3, an atmospheric pressure sensor 51, and an acceleration sensor 52.

  The vehicle control unit 64 includes a motor Mt that operates the throttle valve 18 for controlling the output of the engine 11, the injector 19, the automatic transmission 12, the brake hydraulic pressure control device 25 of the hydraulic brake device, and the like of the controlled unit 30. Control the behavior. In practice, as shown in FIG. 1, the vehicle control unit 64 controls the operation of each part of the controlled unit 30 based on the information related to the road surface gradient θ transmitted from the atmospheric pressure sensor failure detection device 50. An ECU 27, a brake control ECU 26, and an engine control ECU 16. In FIG. 1, the vehicle control unit 64 exists in the vehicle control device 1 including the atmospheric pressure sensor failure detection device 50, but may exist in a computer unit separate from the vehicle control device 1. Good.

  The computer unit 3 of the atmospheric pressure sensor failure detection device 50 includes an atmospheric pressure detection unit 49, an altitude difference calculation unit 53, a travel distance detection unit 54, and a first estimated road surface gradient calculation as main components realized by executing the program. Unit 55, acceleration detection unit 56, second estimated road surface gradient calculation unit 57, atmospheric pressure sensor failure determination unit 58, and road surface gradient selection unit 59. Further, the atmospheric pressure sensor 51 and the acceleration sensor 52 included in the atmospheric pressure sensor failure detection device 50 are connected to the computer unit 3 so as to be communicable.

  The atmospheric pressure sensor 51 is a sensor for detecting the atmospheric pressure P, and is attached to a predetermined position of the vehicle M, for example, in the vicinity of an air filter in an engine room. The signal acquired by the atmospheric pressure sensor 51 is transmitted to the atmospheric pressure detection unit 49. The atmospheric pressure detection unit 49 calculates the atmospheric pressure P based on the signal from the atmospheric pressure sensor 51 and transmits the calculation data to the altitude difference calculation unit 53.

The acceleration sensor 52 is a sensor capable of detecting the gravitational acceleration g as well as the front-rear direction, and is attached to a predetermined position of the vehicle M. The signal acquired by the acceleration sensor 52 is transmitted to the acceleration detection unit 56. Specifically, the acceleration sensor 52 is disposed in the vicinity of the floor surface of the substantially central portion of the vehicle M, and when the vehicle M is placed on a horizontal road surface, a gravitational acceleration g of 9.8 m / s ² is generated. It is a detectable sensor. If the road surface has an inclination of the road surface gradient θ, the value detected by the acceleration sensor 52 is a component force α of the gravitational acceleration g corresponding to the road surface gradient θ as shown in FIG. It can be expressed as g × cos θ. The acceleration sensor 52 can measure various behaviors of the vehicle M in the front-rear, left-right, up-down directions, and the detection data is used for braking control, engine output control, and the like.

  The altitude difference calculation unit 53 calculates the altitude difference Δh [m] between the two points based on the atmospheric pressure difference ΔP between the two points separated by a predetermined distance in the running vehicle M detected by the atmospheric pressure detection unit 49. Part. The predetermined distance is a distance at which the altitude difference Δh can be suitably detected from the atmospheric pressure difference ΔP, and is 100 m in this embodiment. However, 100 m is an example, and any value may be set as long as the altitude difference Δh can be suitably acquired. At this time, the predetermined distance from the first point A is detected by a travel distance detection unit 54 described below.

In the altitude difference calculation unit 53, the above-mentioned 2 is usually based on the relationship (map) between the atmospheric pressure P and the altitude H, which is generally known to be linearly approximated within the altitude range where the vehicle can travel. An altitude difference Δh [m] between points is calculated. Therefore, temperature is not considered here. That is, the altitude difference calculation unit 53 obtains information related to the atmospheric pressure P ₀ from the atmospheric pressure sensor 51 (atmospheric pressure detection unit 49) at the first point A, and is separated from the first point A by a predetermined distance (for example, 100 m). obtaining a signal related to the atmospheric pressure P ₁ from the atmospheric pressure sensor 51 (atmospheric pressure detecting unit 49) in the second points B.

Then, the atmospheric pressure difference ΔP obtained from the atmospheric pressure P ₀ [Pa] and the atmospheric pressure P ₁ [Pa] is applied to a straight line having a predetermined slope indicating the relationship (map) between the atmospheric pressure P and the altitude H. The altitude difference Δh [m] is calculated. The altitude difference calculation unit 53 outputs information related to the calculated altitude difference Δh to the first estimated road surface gradient calculation unit 55. As for the relationship (map) between the atmospheric pressure P and the altitude H, reliable data is acquired in advance and stored in a storage unit (not shown).

In the above description, the altitude difference calculation unit 53 calculates the altitude difference Δh based only on the atmospheric pressure difference ΔP between two points separated by a predetermined distance. However, the present invention is not limited to this, and a temperature sensor (not shown) is provided separately, the outside air temperature t [° C.] is acquired by the temperature sensor, and the altitude difference Δh [from the actual altitude is calculated based on the following [Equation 1]. m] may be obtained. At this time, in the formula [1], P represents the atmospheric pressure at the second point B, and P ₀ represents the atmospheric pressure at the first point A.

The travel distance detection unit 54 detects the travel distance D of the vehicle M. The travel distance D may be obtained in any way, but is detected based on the measurement result of the distance meter 61 in this embodiment. The distance meter 61 is a measuring instrument that detects the travel distance of the vehicle M, and is connected to the computer unit 3 so as to be communicable. The distance meter 61 is connected to a rotational speed sensor attached to the vehicle M, for example, in the vicinity of the output shaft of the automatic transmission 12, and calculates the distance by multiplying the rotational speed output from the rotational speed sensor by the outer peripheral length of the tire. . Specifically, the travel distance detection unit 54 acquires the distance data D ₀ and D ₁ calculated by the distance meter 61 at the first point A and the second point B, respectively, and derives the travel distance D therebetween.

However, the travel distance D may be obtained from the vehicle speed sensor 62 instead of the distance meter 61. That is, the travel distance D is obtained by multiplying the elapsed time from time T ₀ (first point A) to time T ₁ (second point B) by the average vehicle speed Vave between the two points detected and calculated by the vehicle speed sensor 62. You may ask for it. The vehicle speed sensor 62 is attached in the vicinity of the left and right drive shafts 14a and 14b of the vehicle M or in the vicinity of the output shaft of the automatic transmission 12, and is connected to the computer unit 3 so as to be communicable. The vehicle speed sensor 62 detects the rotational angular velocity of the left and right drive shafts 14a, 14b or the output shaft of the automatic transmission 12, and thereby calculates the vehicle speed V.

The travel distance detection unit 54 outputs information related to the calculated travel distance D [m] toward the first estimated road surface gradient calculation unit 55. In the present embodiment, the travel distance D [m] is measured simultaneously when the altitude difference calculation unit 53 measures the atmospheric pressure P ₀ [Pa] and the atmospheric pressure P ₁ [Pa] as described above.

  The first estimated road surface gradient calculation unit 55 calculates the altitude difference Δh [m] between the two acquired points (first point A and second point B) and the travel distance D [m] between the two points (Equation 2 The first estimated road gradient θp [deg], which is the gradient of the road surface on which the vehicle M is traveling, is calculated by substituting it into the equation (1). The first estimated road surface gradient calculation unit 55 outputs information related to the calculated first estimated road surface gradient θp to the atmospheric pressure sensor failure determination unit 58.

(Equation 2)
θp [deg] = sin ⁻¹ (h / D)

  The second estimated road surface gradient calculating unit 57 calculates the second estimated road surface gradient θg based on the component force α of the gravitational acceleration g detected by the acceleration sensor 52 (see the following (Equation 3)). Then, the second estimated road surface gradient calculation unit 57 outputs information related to the calculated second estimated road surface gradient θg to the atmospheric pressure sensor failure determination unit 58.

(Equation 3)
θg [deg] = cos ⁻¹ (α / g)

  The atmospheric pressure sensor failure determination unit 58 calculates a difference by comparing the first estimated road surface gradient θp and the second estimated road surface gradient θg, and is large when the gradient difference Δθ between the two exceeds a predetermined reference value Tr. It is determined that the atmospheric pressure sensor 51 is malfunctioning, and is determined to be normal when the gradient difference Δθ is equal to or less than the reference value Tr. Here, the predetermined reference value Tr is such that when the second estimated road surface gradient θg is assumed to be normal, the second estimated road surface gradient θg and the first estimated road surface gradient θp can be regarded as having the same angle. It is an acceptable value. The predetermined reference value Tr may be derived by experiment or may be derived by calculation, and is a fixed value that is set in advance and stored in the nonvolatile storage unit.

  Since the failure determination of the acceleration sensor 52 is performed by another determination circuit that will not be described, the second estimated road surface gradient θg is determined until the determination result that the acceleration sensor 52 has failed is detected. Suppose that the process is executed under the assumption that it is normal.

  When the atmospheric pressure sensor failure determination unit 58 determines that the atmospheric pressure sensor 51 is normal, the road surface gradient selection unit 59 uses the first estimated road surface gradient θp calculated by the first estimated road surface gradient calculation unit 55 as the vehicle. The control unit 64 selects the road surface gradient θ that is a parameter when the controlled unit 30 is controlled, and transmits it to the vehicle control unit 64. When it is determined that the atmospheric pressure sensor 51 is out of order, when the vehicle control unit 64 controls the controlled unit 30 using the second estimated road surface gradient θg calculated by the second estimated road surface gradient calculating unit 57. And is transmitted to the vehicle control unit 64.

  Then, the vehicle control unit 64 controls each part of the controlled unit 30 based on the selected and transmitted first estimated road surface gradient θp or second estimated road surface gradient θg. By controlling in this way, even when the atmospheric pressure sensor 51 is determined to be abnormal, the control of the controlled unit 30 by the vehicle control unit 64 is performed using the second estimated road surface gradient θg calculated by the acceleration sensor 52 as the road surface gradient. This can be done by setting θ. Therefore, the control can be continued without interruption, and the driver is prevented from feeling uncomfortable.

  At this time, in the control of the engine 11 performed by the engine control ECU 16 in the vehicle control unit 64, for example, according to the road surface gradient θ data transmitted from the road surface gradient selection unit 59 of the atmospheric pressure sensor failure detection device 50, for example, the road surface gradient A control mode in which the fuel supply amount is increased as θ increases and the angle increases, and a control mode in which the fuel supply amount decreases as the road gradient θ decreases and the angle increases may be employed.

  In the control of the automatic transmission 12 performed by the transmission ECU 27, for example, according to the road surface gradient θ data transmitted from the road surface gradient selecting unit 59, for example, the road surface gradient θ increases, and the lower the speed becomes as the angle increases. A control mode that uses a large number of gears may be used, and a control mode that uses many gears on the high speed side as the road surface gradient θ decreases and the angle increases.

  Further, in the control of the hydraulic brake device performed by the brake control ECU 26, for example, according to the road surface gradient θ data transmitted from the road surface gradient selecting unit 59, the braking amount is increased as the road surface gradient θ increases and the angle increases. The control mode may be reduced, and the control mode may be such that the braking amount increases as the road surface gradient θ decreases and the angle increases.

  Further, although not shown in FIG. 1, the vehicle control unit 64 is a hybrid vehicle or an electric vehicle, for example, and has a drive motor, the control for the drive motor transmits from the road surface gradient selection unit 59. Depending on the road surface gradient θ data, for example, the control mode increases the power supply amount as the road surface gradient θ increases and the angle increases, and the power supply increases as the road surface gradient θ decreases and the angle increases. It is good also as a control mode which reduces quantity or regenerates. Each control mode described above is an example, and the control mode may be arbitrarily set.

  Next, the operation of the atmospheric pressure sensor failure detection device 50 will be described based on the flowchart 1 of FIG. First, when the driver turns on the ignition of the vehicle M in order to start driving, the program of the flowchart 1 is started.

In step S10 (atmospheric pressure detection unit 49 and travel distance detection unit 54), the atmospheric pressure detection unit 49 acquires the atmospheric pressure P _{0 of} the first point A (distance data D ₀ ) that is the starting point of distance measurement. . Then, when the travel distance detection unit 54 starts measurement from the first point A (distance data D ₀ ), and the distance data D ₁ reaches the second point B that is, for example, (D ₀ +100 m), The atmospheric pressure P ₁ at the two points B is acquired by the atmospheric pressure detection unit 49.

In step S11 (altitude difference calculation unit 53), an atmospheric pressure difference ΔP between the atmospheric pressure P ₀ and the atmospheric pressure P ₁ is calculated, and an altitude difference Δh [m] is calculated based on the atmospheric pressure difference ΔP.
In step S12 (first estimated road surface gradient calculating unit 55), the first estimated road surface gradient θp is calculated by substituting the altitude difference Δh and the travel distance D into the above equation (2).
Next, in step S13 (acceleration detection unit 56), the acceleration sensor 52 detects the component force α of the gravitational acceleration g orthogonal to the road surface (see FIG. 3).
In step S14 (second estimated road surface gradient calculating unit 57), the gravitational acceleration g and the component force α are substituted into the above equation (3) to calculate the second estimated road surface gradient θg.

  In step S15 (atmospheric pressure sensor failure determination unit 58), the first estimated road surface gradient θp and the second estimated road surface gradient θg are compared. When the gradient difference Δθ between the two does not exceed the predetermined reference value Tr, the process moves to step S16 (atmospheric pressure sensor failure determination unit 58), and it is determined that the atmospheric pressure sensor 51 is normal. When the gradient difference Δθ exceeds a predetermined reference value Tr, the process moves to step S18 (atmospheric pressure sensor failure determination unit 58), and the atmospheric pressure sensor 51 is determined to be in failure.

  In Step S17 (road surface gradient selecting unit 59), the first estimated road surface gradient θp calculated using the atmospheric pressure sensor 51 is transmitted to the vehicle control unit 64 as a road surface gradient θ that is a control parameter, and the vehicle control unit 64 The controlled unit 30 is controlled based on the first estimated road surface gradient θp. Further, in step S19 (road surface gradient selecting unit 59), the second estimated road surface gradient θg calculated using the acceleration sensor 52 is transmitted to the vehicle control unit 64 as a road surface gradient θ that is a control parameter, and the vehicle control unit 64 is transmitted. Controls the controlled unit 30 based on the second estimated road surface gradient θg.

  As is apparent from the above description, according to the first embodiment, the first estimated road surface gradient θp of the road surface calculated using the output value of the atmospheric pressure sensor 51 and the output value of one acceleration sensor 52 The second estimated road surface gradient θg of the road surface calculated based on this is compared. If the gradient difference Δθ between the first estimated road surface gradient θp and the second estimated road surface gradient θg exceeds a predetermined reference value Tr, the failure determination of the atmospheric pressure sensor 51 is regarded as a failure.

  When the atmospheric pressure sensor failure determination unit 58 determines that the atmospheric pressure sensor 51 is normal without exceeding the predetermined reference value Tr, the first estimated road surface gradient θp calculated from the detection data of the atmospheric pressure sensor 51 is used. When it is determined that the atmospheric pressure sensor 51 is out of order, the second estimated road surface gradient θg calculated from the detection data of the acceleration sensor 52 is used as a control parameter for the controlled unit 30.

  As a result, if only one atmospheric pressure sensor 51 and acceleration sensor 52 are provided, control support can be provided, so that a system can be realized at low cost. Even if the atmospheric pressure sensor 51 breaks down, the control support of the controlled unit 30 can be preferably continued using the detection data (second estimated road surface gradient θg) of the acceleration sensor 52, and the reliability is improved.

  Next, a second embodiment will be described. The atmospheric pressure sensor failure detection device 70 according to the second embodiment is different from the atmospheric pressure sensor failure detection device 50 according to the first embodiment in the stop atmospheric pressure storage unit 71, the startup atmospheric pressure acquisition unit 72, and The only difference is that a reference value change control unit 73 is additionally provided (see the broken line portion in FIG. 2). These are control units for changing the value of the predetermined reference value Tr that is a fixed value used in the atmospheric pressure sensor failure determination unit 58 (step S15) of the flowchart 1 to the predetermined reference value Tv that is a fluctuation value. .

  As described above, since the second embodiment is only partly added (changed) to the first embodiment, only the added (changed) part will be described, and the description of the same part will be omitted. The same parts will be described with the same reference numerals. Specifically, in the second embodiment, the reference value Tr (fixed value) is changed to the reference value Tv (variation value) in step S36 of the flowchart 2 which is a part for executing the processing of the flowchart 1 (steps S10 to S19). Change to

  The stop-time atmospheric pressure storage unit 71 stores the end-time atmospheric pressure Pend detected by the atmospheric pressure detection unit 49 immediately before the ignition of the vehicle M is turned off as the stop-time atmospheric pressure Ppast. The startup atmospheric pressure acquisition unit 72 acquires the startup atmospheric pressure Pcurrent when the ignition is turned on for the first time by the atmospheric pressure detection unit 49 after the ignition is turned off.

  The reference value change control unit 73 compares the stop-time atmospheric pressure Ppast stored in the stop-time atmospheric pressure storage unit 71 with the acquired start-up atmospheric pressure Pcurrent. And according to both atmospheric pressure difference (DELTA) Pc, the predetermined reference value Tr of the atmospheric pressure sensor failure determination part (step S15) of the flowchart 1 is set to the predetermined reference value Tv. By controlling in this way, it is possible to perform control in consideration of the change in atmospheric pressure that changes depending on the weather.

  Next, the operation will be described based on the flowchart 2 of FIG. When the ignition of the vehicle M is turned on, the program of the flowchart 2 is started. In step S30, it is confirmed whether or not the stop-time atmospheric pressure Ppast when the ignition is turned off last time is stored in the storage unit. If not stored, the flowchart 1 (step S10-step S19) of Embodiment 1 is implemented by step S40.

  At this time, the fixed reference value Tr is used as the reference value used in the determination in step S15 (atmospheric pressure sensor failure determination unit 58), as in the first embodiment. Thereafter, the program is terminated. If the stop atmospheric pressure Ppast is stored in the storage unit in step S30, the process proceeds to step S31. In step S31, the stop-time atmospheric pressure Ppast stored in the nonvolatile storage unit is read.

  In step S32 (start-up atmospheric pressure acquisition unit 72), the start-up atmospheric pressure Pcurrent is detected and acquired by the atmospheric pressure detection unit 49. In step S33 (reference value change control unit 73), the atmospheric pressure difference (difference) defined as a value obtained by subtracting the stop-time atmospheric pressure Ppast stored in the stop-time atmospheric pressure storage unit 71 from the acquired start-time atmospheric pressure Pcurrent. ) Calculate ΔPc. That is, the atmospheric pressure difference ΔPc becomes a negative value and becomes smaller when the starting atmospheric pressure Pcurrent becomes lower than the stopping atmospheric pressure Ppast and becomes unstable. Further, the atmospheric pressure difference ΔPc becomes a positive value and becomes larger when the start-up atmospheric pressure Pcurrent is higher than the stop-time atmospheric pressure Ppasto become high atmospheric pressure and the atmospheric pressure is stabilized.

  In step S34 (reference value change control unit 73), a predetermined reference value Tv that varies is determined in accordance with the atmospheric pressure difference ΔPc. At this time, the predetermined reference value Tv may be determined in any way, but in the present embodiment, it is determined based on the graph shown in FIG. The graph shown in FIG. 6 is derived by the inventors based on experiments. The smaller the value of the atmospheric pressure difference ΔPc, the smaller the reference value Tv, and the larger the value of the atmospheric pressure difference ΔPc, the smaller the reference value Tv. Great value.

  At this time, as shown in FIG. 6, when the atmospheric pressure difference ΔPc = 0, that is, when the atmospheric pressure P does not change, for example, the reference value Tv = the reference value Tr may be set. As described above, by setting the reference value Tv, for example, when the atmospheric pressure difference ΔPc becomes a negative value and becomes small, that is, when the atmospheric pressure P becomes unstable, the reference value Tv becomes small. For this reason, it becomes difficult to satisfy the condition that it is smaller than the reference value Tv in step S15, and as a result, the determination of the atmospheric pressure sensor 51 is likely to be a failure determination.

  Conversely, when the atmospheric pressure difference ΔPc becomes a positive value and increases, that is, when the atmospheric pressure P becomes stable, the reference value Tv increases. For this reason, it is easy to satisfy the condition that it is smaller than the reference value Tv in step S15, and as a result, the determination on the atmospheric pressure sensor 51 is likely to be normal. In this way, when the atmospheric pressure P is unstable, it is determined that the atmospheric pressure sensor 51 has failed and is not actively used. When the atmospheric pressure P is stable, the atmospheric pressure sensor 51 is normal. It is judged that it is used and is actively controlled.

  In the present embodiment, when the atmospheric pressure difference ΔPc = 0, the reference value Tv = the reference value Tr is set so as to be positioned approximately at the center of the horizontal axis of the graph of FIG. Thereby, even when the atmospheric pressure P is stable, the reference value Tv is changed according to the magnitude of the atmospheric pressure difference ΔPc. However, the present invention is not limited to this. When the atmospheric pressure difference ΔPc becomes positive, the reference value Tv is not always changed, and for example, the reference value Tv = the reference value Tr may be set.

  Next, in step S35, it is confirmed that the ignition is OFF. If it is OFF, the process moves to step S37. If the ignition is not OFF, flowchart 1 (steps S10 to S19) is executed in step S36. At this time, in step S15 (atmospheric pressure sensor failure determination unit 58) in the flowchart 1, the predetermined reference value Tr is changed to the reference value Tv determined in step S34 in the flowchart 2. In step S35, steps S35 and S36 (flow chart 1) are repeatedly processed until the ignition is turned off.

  When the ignition is turned off and the process proceeds to step S37 (stop atmospheric pressure storage unit 71), the end atmospheric pressure Pend detected by the atmospheric pressure detection unit 49 is acquired. In step S38 (stop atmospheric pressure storage unit 71), the stop atmospheric pressure Pend is replaced with the stop atmospheric pressure Ppast and updated. In step S39, Ppast is stored in the nonvolatile storage unit, and the program ends.

  As is clear from the above description, in the second embodiment, the stop-time atmospheric pressure Ppast (= end-time atmospheric pressure Pend) immediately before the ignition of the vehicle M is turned off, and the ignition is first turned on after the ignition is turned off. The startup atmospheric pressure Pcurrent at the time of the start is compared. Then, the reference value change control unit 73 sets the predetermined reference value Tr (fixed value) of the atmospheric pressure sensor failure determination unit 58 (step S15) of the flowchart 1 to the predetermined reference value Tv according to the atmospheric pressure difference ΔPc between them. Change to (variable value). Thus, it becomes possible to determine the failure of the atmospheric pressure sensor 51 with higher accuracy by appropriately responding to the movement of the atmospheric pressure due to weather fluctuations.

  Further, in the second embodiment, the predetermined reference value Tv changed by the reference value change control unit 73 is when the start-up atmospheric pressure Pcurrent is smaller than the stop-time atmospheric pressure Ppast (Pend), that is, at the vehicle stop location. When it is predicted that the atmospheric pressure has become unstable due to low pressure, change it to be smaller. As a result, in a state where the atmospheric pressure is unstable, the atmospheric pressure sensor 51 is easily determined to be out of order and is not actively used, and the control support of the controlled unit 30 can be continued with high reliability. And it becomes possible to obtain optimal driving performance by performing control support of controlled part 30. For example, in cooperation with the shift control used for brake control, the braking force during downhill can be optimized, and excellent driving performance and fuel consumption performance can be obtained by driving the engine 11 in a region where fuel injection is cut. Can do.

In the above description, the altitude difference calculation unit 53 calculates the atmospheric pressure difference ΔP (P ₁ −P ₀ ) between two points separated by a predetermined distance. However, the present invention is not limited to this mode, and atmospheric pressures P ₀ and P ₁ are acquired at two points at time T ₀ (first point A) and time T ₁ (second point B), respectively, and atmospheric pressure difference ΔP (P ₁ -P ₀ ) may be calculated. Then, the travel distance detection unit 54 acquires distance data D ₀ and D ₁ of the distance meter 61 at time T ₀ (first point A) and time T ₁ (second point B), and travel distances between them. D may be derived. As a result, the travel distance D is not constant, but the same effect can be obtained.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus, 3 ... Computer unit, 30 ... Controlled part, 49 ... Atmospheric pressure detection part, 50, 70 ... Atmospheric pressure sensor failure detection apparatus, 51 ... Atmospheric pressure sensor 52... Acceleration sensor 53. Altitude difference calculation unit 54. Travel distance detection unit 55 55 First estimated road surface gradient calculation unit 56 56 Acceleration detection unit 57・ ・ ・ Second estimated road surface gradient calculation unit, 58… Atmospheric pressure sensor failure determination unit, 59… Road surface gradient selection unit, 61… Distance meter, 64… Vehicle control unit, 71… Stop atmospheric pressure storage unit, 72... Startup atmospheric pressure acquisition unit, 73... Reference value change control unit.

Claims (3)

An atmospheric pressure sensor failure detection device for a vehicle control device including a vehicle control unit that controls an operation of a controlled unit of a vehicle based on a road surface gradient,
An atmospheric pressure sensor mounted on the vehicle;
An atmospheric pressure detector for detecting atmospheric pressure by the atmospheric pressure sensor;
A travel distance detection unit for detecting the travel distance of the vehicle;
An altitude difference calculation unit that calculates an altitude difference based on an atmospheric pressure difference between two points separated by a predetermined distance in the running vehicle detected by the atmospheric pressure detection unit;
A first estimated road surface gradient calculating unit that calculates a first estimated road surface gradient of the road surface based on an altitude difference between the two points and a travel distance between the two points separated by the predetermined distance detected by the travel distance detecting unit; ,
An acceleration sensor mounted on the vehicle;
An acceleration detection unit that detects a gravitational acceleration component perpendicular to the road surface by the acceleration sensor;
A second estimated road surface gradient calculating unit that calculates a second estimated road surface gradient based on the detected gravitational acceleration component force;
An atmospheric pressure sensor failure determination unit that compares the difference between the first estimated road surface gradient and the second estimated road surface gradient with a predetermined reference value to determine whether the failure is normal or not;
When the atmospheric pressure sensor failure determination unit determines that the atmospheric pressure sensor is normal, the first estimated road surface gradient is used, and when it is determined that the atmospheric pressure sensor is defective, the second estimation is performed. A road surface gradient selecting unit which sets a road surface gradient as a road surface gradient when the vehicle control unit controls the controlled unit;
An atmospheric pressure sensor failure detection device for a vehicle control device. In claim 1,
A stop-time atmospheric pressure storage unit that stores a stop-time atmospheric pressure detected immediately before the ignition of the vehicle detected by the atmospheric pressure detection unit;
After the ignition is turned off, a startup atmospheric pressure acquisition unit that acquires the startup atmospheric pressure detected by the atmospheric pressure detection unit when the ignition is first turned on;
A reference value change control unit that compares the atmospheric pressure at the time of stop and the atmospheric pressure at the time of startup, and changes the predetermined reference value of the atmospheric pressure sensor failure determination unit according to a difference between the two,
An atmospheric pressure sensor failure detection device for a vehicle control device. In claim 2,
The atmospheric pressure sensor failure of the vehicle control device changes the predetermined reference value changed by the reference value change control unit in a direction in which failure is easily determined when the startup atmospheric pressure is smaller than the stop atmospheric pressure. Detection device.

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