JP3752872B2 - Slope start assist device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slope start assisting device that makes it easy and smooth to start a vehicle on an uphill road.
[0002]
[Prior art]
When starting a vehicle in the middle of an uphill road, the driver operates the brake device, the accelerator pedal, and the clutch in a coupled state. It is necessary to do. In this situation, it is difficult for a driver who is not familiar with driving skills to start the vehicle smoothly without causing the vehicle to reverse or stop the engine.
[0003]
Therefore, in order to easily and smoothly start on an uphill road, a truck or the like is equipped with a slope start assist device. This slope start assist device maintains the braking force of the wheel cylinder when the vehicle is stopped by a brake operation, and determines whether the clutch is disengaged or disengaged based on the stroke position of the clutch pedal when starting, and the clutch changes from disengaged to engaged It is configured to release the brake. Further, an adjustment function is provided for adjusting a change with time of the clutch contact (disconnection / disconnection) due to wear of the clutch plate or the like.
[0004]
[Problems to be solved by the invention]
As in the prior art, a clutch stroke sensor is indispensable for determining the brake release timing based on the stroke position of the clutch pedal. In addition, since the appropriate position for switching between clutch disengagement and engagement due to wear of the clutch plate deviates from the initial setting position due to changes over time, it is necessary to adjust this by any method. As a method, a switch for adjusting the contact (disconnection / disconnection) position of the clutch is provided and the driver changes the set position while sensing the state of the clutch by manual operation, or a clutch switch is provided with a pressure switch in the clutch portion. There is a method of automatically moving the set position by the amount of wear. However, each of these adjustment methods requires a dedicated switch or sensor, and when adjusting by manual operation, the driver must make adjustments at any time, and the adjustment operation is complicated, difficult to understand, and troublesome. There's a problem.
[0005]
Accordingly, an object of the present invention is to provide a slope start assisting device that can always perform stable control without requiring adjustment without using a dedicated switch or sensor.
[0006]
[Means for Solving the Problems]
To achieve the above object, hill start auxiliary device according to the present invention, the engine load state obtained from the control rack position information of the fuel injection pump installed in an engine of a vehicle, the engine speed obtained from the engine rotation information, Further , it is determined whether or not the braking force by the braking force holding means should be released using the value of the accelerator opening change speed obtained from the accelerator opening information , and there is an engine load, the engine speed decreases or the idle speed The braking force by the braking force holding means is released when the accelerator opening change speed is within a predetermined range .
[0007]
Here the engine load state, Ri Tona a control rack position and the rack position change rate is controlled rack position information in the two-dimensional map control rack position and the rack position change rate takes a progressively larger value toward the upper right, the closer to the upper right corner is determined to be large heard. The rack position change speed includes a negative region on the two-dimensional map, and the engine load state is set to three or more regions including no load from the lower left to the upper right of the map.
With this configuration, it is possible to start the vehicle on the uphill road easily and smoothly, and the determination of the braking force release is made finely, so that malfunction of the device is suppressed.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing an embodiment of a slope start assisting device according to the present invention. This slope start assist device is applied to an air brake system as a vehicle braking control device as shown in the figure. Here, the transmission of the vehicle to which the present embodiment is applied is an ordinary manual transmission (not shown), and the fuel supply system for supplying fuel to the engine is an electronic system composed of an electronic governor and a row type fuel injection pump. It is a controlled fuel injection pump system. The fuel injection amount control, the fuel injection timing control, the fuel feed rate control, etc. are performed using a computer.
[0009]
As shown in FIG. 1, the air brake system includes an air tank 1, an air chamber 2 of an air brake mechanism (not shown) as a braking device, and an air passage 3 connecting the two. . A brake valve 4 'that opens and closes in response to depression of the brake pedal 4, a stop lamp switch (SW) 5 that operates when air pressure is supplied to the air passage 3 and outputs a signal. And the slope start assistance apparatus 10 is provided.
[0010]
The slope start assisting device 10 includes a brake control valve (electromagnetic valve) 6 as a braking force holding unit and a control device 7 that controls the valve 6. When the control signal for starting the auxiliary function is supplied from the control device 7 (for example, supply of drive current), the brake control valve 6 blocks the air passage 3 and maintains the air pressure in the air chamber 2 as a braking force. On the other hand, when a control signal for terminating the auxiliary function is supplied from the control device 7 (for example, cutting off the drive current), the air pressure in the air chamber 2 is released to the atmosphere to release the braking force. .
[0011]
The control device 7 receives a stop signal (brake) from the stop lamp SW5, a parking signal (park) from the parking (P) brake SW12, a neutral signal (nut) from the shift lever neutral SW13, a vehicle speed pulse signal (ve) from the vehicle speed sensor 14, A rack position signal (rack) of the control rack of the fuel injection pump, an engine speed signal (rpm), an accelerator opening signal (accl), and other signals (not shown) are input from the electronic governor control device 11. The control device 7 determines the start / end of the slope start assist function using these input signals, and outputs a control signal (aus) to the brake control valve 6 based on the determination result.
[0012]
The determination of clutch disengagement / engagement that determines the brake release timing can be made based on engine-related information such as engine generated torque, engine speed, and accelerator opening. However, as the engine output increases, the follow-up of the engine speed tends to be delayed with respect to the depression of the accelerator pedal. Therefore, if the clutch disengagement / engagement is determined based on the depression of the accelerator pedal and the change in the engine speed, the determination time is delayed and the feeling at the time of start is deteriorated.
[0013]
Therefore, in the present invention, as described above, the rack position signal of the control rack of the fuel injection pump is taken in, and the intention of the driver to start the vehicle is read from the rack position signal. This is because the control rack position of the fuel injection pump corresponds to the depression of the accelerator pedal. Then, the brake is released by estimating that the clutch is engaged from the disengagement from the change state of the rack position signal. At this time, more reliable control can be performed by using the rack position and the rack position change speed.
[0014]
In addition, in this type of estimation of clutch disengagement / engagement based on engine-related information, there is a possibility that erroneous determination (error cancellation) may occur due to the operation of the compressor by an air blower or an air conditioner by the driver. This is because changes in the rack position and engine speed during idling or compressor operation may show changes similar to those at the start of the vehicle. Therefore, in the present invention, as will be described later, information on the accelerator opening change speed is added to the determination of the end of the auxiliary function, and a negative region of the rack position change speed is added to the two-dimensional map for determining the engine load state. Suppresses the occurrence of malfunctions.
[0015]
FIG. 2 is a diagram illustrating an example of a block configuration of the control device 7. As shown in the figure, the signal processing circuit 21 receives a rack position signal (rack), and outputs a rack which is a rack position signal after the signal processing and fgack which is a rack position change speed signal. Further, the idling rack position calculation circuit 22 inputs “track” and outputs “adltrack” which is an idling rack position signal. The engine load state determination unit 23 determines the engine load state using these signals, and outputs f_rack, which is a flag signal of the engine load state.
[0016]
A load state determination method in the engine load state determination unit 23 will be described with reference to FIG. The determination of the engine load state is performed based on the rack position and the rack position change speed value in the two-dimensional map of FIG. The white portion on the left or lower left of the two-dimensional map is a region where the engine load is not present, and the engine load becomes a region where the engine load is small, medium, or large as it moves to the right or upper right. That is, in this two-dimensional map, it is determined that the engine load is larger in the upper right of the map where both the rack position and the rack position change speed take a large value. Further, the rack position change speed includes a negative region. Therefore, for example, as shown in FIGS. 3A to 3D, even if the rack position is the same, the load state is determined as none, small, medium, or large depending on the magnitude and polarity of the rack position change speed. As a result, the determination of the engine load state is finely performed, and there is an effect that it is possible to accurately determine whether the slope start assist function is finished. Here, the engine load state is divided into four regions (no, small, medium, large), but the above-described effects can be obtained if the engine load state is three regions (no, small, large) including no load.
[0017]
Returning to FIG. 2, the signal processing circuit 24 inputs the engine speed signal (rpm) and outputs the signal speed frpm and the engine speed change speed signal fgrpm. . Further, the idling rotation speed calculation circuit 25 inputs frpm and outputs adlrpm which is an idling engine rotation speed signal. The engine rotation state discriminating unit 26 discriminates the engine rotation state using these signals, and outputs a flag signal f_rpm1 indicating a change speed of the engine rotation and a flag signal f_rpm2 indicating the engine speed. Further, the signal processing circuit 27 receives the accelerator opening signal (accl), and outputs the accelerator opening signal faccl and the accelerator opening changing speed signal fgaccl after the signal processing. Here, the signal processing circuits 21, 24, and 27 perform signal processing using, for example, a low-pass filter, and calculate each change speed using a differentiation circuit. The vehicle stop determination unit 28 receives the vehicle speed pulse signal (ve) and outputs f_stop which is a vehicle stop / movement flag signal.
[0018]
The start / end determination unit 29 includes these signals (f_rack, f_rpm1, f_rpm2, faccl, fgaccl, f_stop), a stop lamp SW state flag signal (f_break), a P brake SW state flag signal (f_park), and a neutral SW. State flag signal (f_nut), ABS state flag signal (f_abs), ASR state flag signal (f_asr), main SW ON / OFF state flag signal (f_main), etc. are input and these signals are used. The start / end of the auxiliary function is determined, and a control signal (aus) is output to the valve 6 according to the result.
[0019]
FIG. 4 is a diagram illustrating an example of a specific logical configuration of the start / end determination unit 29. In the following description, f_ written at the head of the input signal indicates a flag signal.
First, auxiliary function start determination will be described. As a premise, as shown in the figure, when any signal of main SW off (f_main1), P brake use (f_park1), ABS control on (f_abs1) is input to the OR circuit 31, the output is output to the OR circuit 31. As a result, the switch 32 is opened and the start of the auxiliary function is prohibited. Otherwise, the switch 32 is closed and the start determination is performed under the following conditions.
[0020]
As shown in the figure, when the foot brake is depressed (f_break 1), the vehicle is stopped (f_stop 0), and the output of the OR circuit 34 is input to the AND circuit 33, an output is generated in the AND circuit 33. At this time, the switch 35 is closed to the start determination side, and a control signal (aus) for starting the auxiliary function is output. Here, the output of the gear neutral (f_nut0) and the AND circuit 36 is input to the OR circuit 34. The AND circuit 36 outputs when no engine load is applied (f_rack0) and when the engine is rotated (f_rpm0).
[0021]
Next, the end determination of the auxiliary function will be described. The engine speed change speed f_rpm1 is flagged as large = 2 and small = 1 according to the magnitude of the speed of change, and the engine speed f_rpm2 is, for example, according to the speed difference with respect to the idle speed. Flags are divided into large = 3, medium = 2, and small = 1. As shown in the figure, when the main SW off (f_main1), P brake use (f_park1), ASR brake control on (f_asr1), and the output of the AND circuit 42 are input to the OR circuit 41, an output is generated in the OR circuit 41. . At this time, the switch 35 is closed to the end determination side, and the auxiliary function ends. Here, the AND circuit 42 receives the gear (f_nut1) and the output of the OR circuit 43. The OR circuit 43 inputs the outputs of the AND circuits 51, 61, and 71.
[0022]
The AND circuit 51 determines a condition when the engine load is small, and inputs the engine load small (f_rack1) and the output of the OR circuit 52. Here, the output of the AND circuits 53, 54 and 55 is input to the OR circuit 52. The outputs of the AND circuit 56 and the OR circuit 57 are input to the AND circuit 53. The AND circuit 56 inputs an engine speed flag larger than 1 (f_rpm2A) and an accelerator opening change speed larger than a predetermined value (fgacc1). The OR circuit 57 inputs information (f_rpm1A) and (f_rpm1B) as to whether or not the engine rotation change speed flag has changed to the larger side. The outputs of the AND circuit 58 and the OR circuit 59 are input to the AND circuit 54. The AND circuit 58 inputs that the engine speed change speed flag is greater than 1 (f_rpm1C) and the accelerator opening change speed is within a predetermined value range (fgaccl2). The OR circuit 59 inputs information (f_rpm2B) and (f_rpm2C) indicating that there is a change to the larger engine speed flag. The AND circuit 55 is input when the vehicle is moving (f_stop1) and the accelerator opening is less than a predetermined value (faccl1).
[0023]
The AND circuit 61 determines a condition when the engine load is medium, and inputs the output of the OR circuit 62 during the engine load (f_rack2). Here, the output of the AND circuits 63, 64 and 65 is input to the OR circuit 62. The AND circuit 63 is inputted with a change (f_rpm1D) and an accelerator opening change speed larger than a predetermined value (fgaccl1) on the larger side of the engine rotation change speed flag. The AND circuit 64 receives the accelerator opening change speed within a predetermined value range (fgaccl2) and the output of the OR circuit 66. The OR circuit 66 inputs information (f_rpm2D) and (f_rpm2E) indicating that there is a change to the larger engine speed flag. The AND circuit 65 is input with the vehicle moving (f_stop1) and the accelerator opening less than a predetermined value (a predetermined value smaller than a predetermined value of faccl1) (faccl2).
[0024]
The AND circuit 71 determines a condition when the engine load is large, and inputs the engine load large (f_rack3) and the output of the OR circuit 72. Here, the OR circuit 72 inputs the output of the AND circuit 73 and the vehicle moving (f_stop1). The AND circuit 73 inputs an engine speed change speed flag of 2 or more (f_rpm1E) and an engine speed flag of 2 or more (f_rpm2F). In addition, the OR circuit 43 receives a change (change in the flag 3 or more) (f_rpm2G) on the larger engine speed flag side.
The start / end determination unit 29 determines the start / end of the auxiliary function as described above, and outputs a control signal (aus) to the valve 6 according to the result.
As described above, the end determination unit is based on the condition that “there is an engine load and the engine speed is decreased or is less than or equal to the idling speed”. If it is small, the determination condition is complicated, and conversely, if the load is large, the determination condition is simplified.
[0025]
Next, as an example, a determination operation in the case where the driver blows the engine while the braking force is maintained by the braking device will be described. The end of the auxiliary function must not be judged when idling. FIGS. 5A and 5B show the engine load state flag, FIG. 5B shows the engine speed flag, FIG. 5C shows the accelerator opening change speed, and FIG. 5D shows the change in the control signal. is there. Now, when the driver performs idling of the engine in the gear-engaged (f_nut1) state, for example, at a time around 0.16 (s) shown in FIG. 5, the engine load state f_rack2 and the engine speed f_rpm2E are Become true. If the accelerator opening change speed is not considered, an output is generated via the AND circuit 61, the OR circuit 43, the AND circuit 42, and the OR circuit 41 in FIG. Occur. In the present invention, whether or not the accelerator opening change speed is within a predetermined range (fgaccl2) is input to one of the AND circuits 64, and the engine speed (f_rpm2E) is input to the other. The speed of change in the accelerator opening during idling is out of the range of fgaccl2 as shown by the circles in FIG. 5C. In this case, the condition of the AND circuit 64 is not satisfied, and therefore the AND circuit 61 is not satisfied. No output. As a result, the erroneous determination as described above can be prevented.
[0026]
The present invention is not limited to the above embodiment, and the clutch pedal is operated only at the start in consideration of the slow speed required by the driver. The present invention can also be applied to a slope start assist device for a vehicle equipped with a mechanical automatic transmission that automatically shifts by electronic pneumatic control and a normal row type fuel injection pump.
[0027]
【The invention's effect】
According to the present invention, the value of the accelerator opening change rate obtained from the engine load state obtained from the rack position information of the control rack of the fuel injection pump that changes when the accelerator pedal is depressed to start the vehicle and the accelerator opening information. Since the braking device is released using the vehicle, it is possible to easily and smoothly start the vehicle on the uphill road and to prevent erroneous release of the braking device. Further, since the brake device is released using the rack position information or the like, the clutch stroke sensor is not required, the cost is reduced, and the control is always stable because it is not affected by the wear of the clutch plate. . Further, a switch for fine adjustment of the clutch stroke is not required, so that a troublesome adjustment operation is not required and costs are reduced.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of a slope start assist device according to the present invention.
FIG. 2 is a diagram illustrating an example of a block configuration of a control device.
FIG. 3 is a diagram for explaining a determination method in an engine load state determination unit;
FIG. 4 is a diagram illustrating an example of a specific logical configuration of a start / end determination circuit.
5A is an engine load state flag, FIG. 5B is an engine speed flag, FIG. 5C is an accelerator opening change speed, and FIG. 5D is a diagram showing a control signal change when the engine is idling. It is.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Air tank 2 Air chamber 3 Air passage 4 Brake pedal 4 'Brake valve 5 Stop lamp 6 Brake control valve 7 Control device 10 Slope start assistance device

Claims (4)

Braking force holding means for holding the pressure of the fluid that operates the braking device of the vehicle and maintaining the braking force in an activated state;
Engine load state obtained from the control rack position information of the fuel injection pump mounted on the engine of the vehicle, the engine speed determined from the engine speed information, and, in the accelerator opening speed determined from the accelerator opening information Control means for releasing the braking force maintained by the braking force holding means using a value ,
The control means determines to release the braking force when the engine load is present, the engine speed is reduced or equal to or less than the idle speed, and the accelerator opening change speed is within a predetermined range. <br/> A slope start assist device characterized by that. The control rack position information includes a control rack position and a rack position change speed.
The slope starting assistance device according to claim 1, wherein: A map for determining the engine load state from the control rack position and the rack position change speed, comprising a two-dimensional map in which the control rack position and the rack position change speed are gradually increased toward the upper right,
The engine load condition, the on two-dimensional map, hill-start assist according to claim 2, wherein it is determined that the more large listen closer to the right. The rack position change speed includes a negative region, and the engine load state is set to three or more regions including no load from the lower left to the upper right of the two-dimensional map. 3. A slope start assistance device according to 3 .

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