JPH01113535A - Throttle valve control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To avoid a risk of a slip in a low friction road so as to ensure a safety of drive by providing a desired throttle opening degree compensating means for compensating a desired value set by a desired throttle opening degree setting means in accordance with an output value from a road surface friction setting means. CONSTITUTION:A detecting means 27 detects a manipulation amount of an accelerator manipulating element 27a, and a desired throttle opening degree setting means 28 sets a desired throttle opening degree value thetad1 demanded by the driver. Meanwhile, when a detecting means 29 detects a slip accompanying with a transition from a high friction road into a low friction road in accordance with outputs from drive wheel rotational speed sensors 21FR... and an acceleration sensor 22, a road surface friction setting means 30 calculates a maximum road surface friction from an output from a gravitational acceleration sensor 22. A compensating means 31 computes a compensating coefficient K for the throttle opening degree desired value thetad1 so as to compensate and limit the desired throttle opening degree to a limit value thetad2, to avoid a slip on the low friction road surface, thereby it is possible to safely run the vehicle.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a throttle valve control system for an internal combustion engine that corrects the operation m of an accelerator operator operated by a driver in accordance with the driving conditions of the vehicle and sets the throttle opening degree. be.

[Conventional technology]

As this type of throttle valve control device,
0-. The one published in Publication No. 164630 is known. Here, the driving situation of the vehicle is detected, such as the gear shift position, the wheel slip situation determined from the difference in wheel speed between the front vehicle width ζ and the rear wheel, and the operation m (
This system automatically changes the functional relationship between the accelerator (accelerator) and the throttle opening to obtain throttle opening control that is optimal for the current driving situation.

[Problems to be solved by the invention]

The problem here is that when the driving environment changes while the vehicle is running,9 for example, when the driver changes from a high-μ road to a low-μ road, and when it is necessary to limit the output torque due to external factors, There is a risk of making a maneuvering error such as pressing the accelerator too hard without realizing it. Considering the environment, there was a risk that the output torque would be excessive. This is disadvantageous in terms of safety. Therefore, the present invention detects changes in the road surface μ while the vehicle is running from information from various sensors, and if there is a danger in setting the throttle opening as requested by the driver, the throttle opening is lower than the above-mentioned request. It is an object of the present invention to provide a throttle valve control 5ill for an internal combustion engine that is capable of regulating the output torque at that time by limiting the output torque to 5ill.

[Means to solve the problem]

For this reason, the present invention includes means for detecting the operation amount of the accelerator operator, target throttle opening setting means for setting the eye mii of the driver-required throttle IIIa corresponding to the accelerator operation amount, and the rotation speed of each wheel. a slip determination means for determining slip from each output of the sensor and the acceleration sensor; a road surface μ setting means for calculating the road surface μ from the output of the acceleration sensor at that time; and a target value set by the target throttle opening setting means. and target throttle opening correction means for correcting with the output value of the road surface μ setting means. 1. Effect] Therefore, depending on the road surface μ obtained from various sensors while the vehicle is running, the required throttle opening amount due to the driver's accelerator operation can be substantially limited based on the information on the road surface μ. It can avoid slips on low-μ roads and ensure driving safety.

[Embodiment 151] Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In the figure, numeral 1 is the engine, and torque converter 2
Power is transmitted to the transmission 3 via the transmission. The output shaft 4 of the transmission 3 is
It is connected to a carrier 5a in a planetary gear differential gear S, and output torque is distributed to the sun gear Itsc and the ring gear 5d through an M star pinion 5b provided on the carrier 5a. This torque distribution is, for example, 40% to the sun gear 5C and 60% to the ring gear 5d. The sun gear 5C is connected to the rear input shaft G, and transmits torque to the rear axles 8R and 8L via a differential gear W17. On the other hand, the ring gear 5d is connected to the front input shaft 11 via a gear 9 integrated therewith and a gear 10 that meshes with the ring gear 5d. , 13L. Further, at the rear end of the front input shaft 11, there is a distribution shaft 15 for torque split control via a split clutch 14 of a wet type multi-plate clutch 31! The torque distributed from the front input shaft 11 via the distribution shaft 15 is transmitted to the rear input shaft 6 via gears 16 and 17. The split clutch 14 is hydraulically controlled via a hydraulic control circuit 18 to enable torque to be transferred from the front input shaft 11 to the rear and between the input shaft 6. The hydraulic control circuit 18 performs its functions through the action of the solenoid valve 19. The four-wheel drive vehicle has rotation speed sensors 21FR provided on each wheel 20F R, 20F L, 20RR, and 20RL. 21FL, 21RR, 21RL, and a gravitational acceleration sensor 22. Steering angle sensor 23. Furthermore, various other sensors are installed B111, and output signals from these sensors are supplied to the electronic control unit 24. Then, the electronic control unit 24 calculates a clutch pressure control signal 25 for the solenoid valve 19 based on the given information according to a predetermined program. Throttle control signal for engine output control @26. In addition, it outputs output signals for operation control. In particular, the electronic control unit 24 has a configuration as shown in FIG. 2 for throttle opening control. Here, there is a means for detecting the operation amount of the foot-operated accelerator operator 27a. 28. Above rotation speed sensor 2
Slip detection means 29 which processes the output signals of 1F R, 21F L, 21RR and 21RL, and detects a slip from the results of the arithmetic processing, the output value of the steering angle sensor 23, and the output value of the acceleration sensor 22. Road surface μ setting means 30 for setting the road surface μ value at that time when the slip detection means 29 detects a slip. Target throttle opening correction for correcting the target value θd1 from the target throttle opening setting means 28 at that time according to the characteristics of the road surface μ using the information from the road surface μ setting means 30, and changing the target value θd1 to the target value θd. Means 31 is constructed. Note that the slip detection means 29 has a configuration as shown in FIG. 3. Here, in order to calculate the acceleration by differentiating the output signal for each rotation sensor, each rotation speed output NFR,
An average speed calculation means 321 that takes an arithmetic average of the NFL, an average speed calculation means 331 that takes an arithmetic average of the respective rotational speed outputs NRR and NRL of the rotation sensors 21RR and 21RL, and an output value VF and VR of the vehicle average speed calculation means 32 and 33. Calculate the difference ΔV,
Front and rear wheel rotation difference calculation means 41. Further, a target longitudinal rotation speed difference setting means 42 which is set from the output value V of the four-wheel average speed calculation means 34 which takes the arithmetic average of V" and V", the output value λ of the steering angle sensor 23, etc. There is a comparing means 43 for comparing the rotational difference ΔV and the target front and rear wheel rotational speed difference ΔVS. Also, here, the output value (■) of the four-wheel average speed calculating means 34 is differentiated at a predetermined calculation cycle to obtain a differential value dv/dt. There is a differentiating means 35 for calculating the differential value dv/dt-GV and the output value G of the acceleration sensor 23 by ΔG-GV-G,
Difference signal detection means 31 for determining the difference ΔG. Threshold value ΔG in advance
Comparison means 39 for comparing the differential value ΔG and the threshold value ΔGS. The comparing means 39 and the comparing means 43 constitute a slip determining means 40 which determines that a slip has occurred in either front wheel slip, rear wheel slip, or four wheel simultaneous slip under each condition. In such a configuration, the state of calculation in the electronic control unit will be specifically explained with reference to the diagram of FIG. In step 8101, the rotation speed sensors 21FR, 21F
L output 1! The average speed calculation means 32 arithmetic averages the NFR and NFL, and calculates the average IE (VF-(NFR+NFL)/2
seek. Next, in step 5102, the rotation speed sensor 21RR. 21RL output values NRR and NRL are average speed calculation handff
133r phase f+[l average L, average fill VR-(NRR
+NRL)/2. Then, in step 5103, the four-wheel average speed calculation means 34 calculates the output value V-(Vf +V
Find r)/2. Further, in step 5104, the average speed vr of both the front wheels and the rear wheels is determined.
, vr, the front and rear wheel rotation speed difference calculation means 41 calculates
The front and rear wheel rotational speed difference VS is determined by Vs - Vf - Vr. In step 5105, the average speed V of the four wheels and the steering angle sensor 2 are determined.
A target front and rear wheel rotation speed difference VSd, which is theoretically set from the output of No. 3, etc., is calculated by a target front and rear wheel rotation speed difference setting means 42. For example, the target front and rear wheel rotational speed difference is an increasing function of the steering angle, as shown in FIG. 8, and the vehicle speed has an upwardly convex characteristic with a certain vehicle speed as Max. Next, in step 8106, the comparing means 43 sets the ratio ML/, 1 and 1ΔVS−ΔvSd1 to a certain predetermined setting value.
If I AVs −ΔVsdl >Kt, step 81
Move to 07. Then, the slip determination means 40 determines that 1
When ΔVa −ΔVsdl >Kt and vS≧0, check if the front wheel is slipping in step 8108.
ll Constant L-t, :J, ri I Δvs −VSdl >
When Kt vs<0, it is determined in step 3109 that rear wheel slip has occurred. When it is determined that the front wheel slips or the rear wheels slip, the electronic unit 24 issues a clutch pressure control signal based on this determination result, activates the hydraulic control circuit 18, and adjusts the torque between the front wheel side distributed torque and the rear wheel side distributed torque. Adjust the movement of. So-called torque split control is performed. Further, in the next step 5105, the differential 1flGV-dv/dt is obtained from the output value V of the four-wheel average speed calculating means 34 using the differentiating means 36. Also, step 51
17, the difference signal detection means 37 calculates the difference between the output value G of the acceleration output value correction means 3G and the differential WiGv. That is, the calculation ΔG-GV-G is performed. As a result, in 5112, the comparison means 39 compares the absolute value IΔG1 of the difference value ΔG with the threshold value ΔGS given by the threshold II setting means 38. This situation can be seen in Figure 5. If IΔGl>ΔGS, step 511
3, and if ΔG≧0 in the slip determination means 40, then 4
Wheel slip. If ΔG<0, it is determined that there is a grip. The determination result is supplied from the slip detection means 29 to the road surface μ setting means 30 in step 5113. Here, the output value of the acceleration sensor 22 at the time of slip judgment is used as the output value of the steering angle sensor 23.
The road surface μlaX is calculated from the output value G' from the acceleration output value correction 36, which is corrected using the output value of the four-wheel average speed calculation means 34 and the output value (2) of the four-wheel average speed calculation means 34. Then, in Stella 5117, μWaX is determined as the road surface μ at that time, and this is adopted for control. Next, referring to FIG. 6, throttle control will be specifically explained. In step 5201, the detection means 27 detects the amount of operation of the accelerator operator 27a. Next, in step 202, the target throttle opening setting means 28 sets a target throttle opening degree value θd1 for the operation '8 request. Then, in the next step S203, the target throttle opening correction means 31 uses the output value of the road surface μ setting means 30.
Obtain the correction coefficient k of the target value θd1 in step $204.
The target value θd'l"'KZθd1 is obtained. In this case, the relationship between the accelerator opening (when the operator 17a is depressed) and the throttle opening is based on the high μ road characteristic μH, and the road surface μ setting means 30 The above correction coefficient K (21
) can be obtained (see Figure 7). In this way, when the driving environment while the vehicle is running changes, for example, from a high μ road to a low μ road, μL is determined from the output value of the gravitational acceleration sensor when detecting a slip, and the throttle opening target value is set to ensure safe driving. can be regulated to a limit value Od. Although a four-wheel drive vehicle has been described as an embodiment of the present invention, the present invention is not limited thereto and can be similarly applied to a two-wheel drive vehicle.

【Effect of the invention】

As described in detail above, the present invention can substantially limit the throttle opening required by the driver's accelerator operation depending on the road surface μ obtained from each hardness sensor while the vehicle is running. It can avoid the risk of slipping and ensure driving safety.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view of a four-wheel drive vehicle showing an embodiment of the present invention, FIG. 2 is a block diagram for explaining the configuration of an electronic control unit according to the present invention, and FIG. FIG. 4 is a block diagram for explaining the configuration of the detection means, and a flowchart showing a control program for slip detection. Figure 5 is a microcosm of determining the acceleration limit by comparing the output value of the acceleration sensor and the differential value of the average value of the rotation speed sensor of each wheel. Figure 6 is a flowchart showing the control program for correcting the throttle opening target value. , FIG. 7 is a diagram showing the relationship between throttle opening and accelerator opening for target value correction, and FIG. 8 is a graph regarding changes in steering angle. 21FR, 21FL, 21RR, 21RL... Rotation speed sensor, 22... Acceleration sensor, 23... Steering angle sensor, 24... Electronic control unit, 25... Clutch pressure control signal, 26...・Throttle opening signal, 27・
... accelerator operation amount detection means, 28 ... target throttle opening setting means, 29 ... slip detection means, 30.
...Road surface μ setting means, 31...Target throttle opening correction means. Patent Applicant Fuji Heavy Industries Co., Ltd. Agent Patent Attorney Nobu Kobashi Ukiyo Patent Attorney Susumu Murai

Claims (1)

[Claims] means for detecting the operation amount of the accelerator operator; target throttle opening setting means for setting a target value of the driver-requested throttle opening corresponding to the accelerator operation amount; and a rotation speed sensor and an acceleration sensor for each drive wheel. a slip determining means for determining slip from each output; a road surface μ setting means for calculating a road surface μ from the output of the acceleration sensor at that time; and a road surface μ setting means for calculating the target value set by the target throttle opening setting means. 1. A throttle valve control device for an internal combustion engine, comprising: target throttle opening correction means for correcting with an output value.