JP3656293B2 - Automatic transmission control device for vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic transmission control device for a vehicle, and more particularly to an automatic transmission control device for a vehicle in which a control pattern (that is, a shift map) in an automatic transmission is switched in accordance with a traffic congestion situation on a traveling road. .
[0002]
[Prior art]
Currently, as a control device for an automatic transmission, a plurality of control patterns (modes), for example, a normal mode that keeps a relatively high shift stage at a low vehicle speed and suppresses downshifting, and a relatively high vehicle speed There is a type having a shift-down mode in which a low shift stage is maintained and shift-down is frequently performed, and a driver that can be switched by a switch has been put into practical use. For example, on a road with a large amount of traffic where it is difficult to maintain a safe inter-vehicle distance, the driver sets the downshift mode so that the engine brake can be easily applied and can travel safely.
[0003]
Various technologies have been proposed for automatically changing the control pattern by further evolving the control device for the automatic transmission. For example, in Japanese Examined Patent Publication No. 6-58141, a current position is detected by a navigation device, and a state of a traveling road (for example, a mountain road) at the current position is determined from road information held, and an automatic transmission A technique for automatically switching the control pattern to one corresponding to a mountain road has been proposed.
[0004]
[Problems to be solved by the invention]
Currently, traffic jams occur regularly on general roads with heavy traffic. Here, the flow of the vehicle is organized by traffic lights installed at the intersection, but there are various road positions (city center, urban area, etc.), road length, number of lanes, traffic lights lighting cycle, etc. Factors are intertwined and cause traffic jams.
[0005]
In view of this, the present inventor has devised that the vehicle is allowed to travel safely by automatically switching to the shift-down mode on a road with a large amount of traffic where it is difficult to maintain a safe inter-vehicle distance. Here, conventionally, whether or not there is a traffic jam was determined based on the average speed within a certain time, or the depression frequency of the accelerator and brake, but in this method, That is, it was not possible to detect a state that was slightly crowded and it was difficult to maintain the inter-vehicle distance. On the other hand, if the vehicle can travel relatively smoothly because it is not possible to properly determine whether it is a traffic jam or not, if it is judged that there is a traffic jam and the mode is switched to the downshift mode, the vehicle speed or the accelerator / brake depressing frequency As a result of this slight difference, shifting up and down of the gear position is repeated, which causes discomfort to the driver.
[0006]
The present invention has been made in order to solve the above-described problems, and provides an automatic transmission control device for a vehicle that can accurately determine the degree of traffic congestion on a road and select an appropriate control pattern. .
[0007]
[Means for Solving the Problems]
In order to achieve the above object, in claim 1, based on one of a first control pattern for selecting a high shift speed at a low vehicle speed and a second control pattern for selecting a low shift speed at a high vehicle speed, An automatic transmission control device for a vehicle that controls a shift stage of an automatic transmission according to a traveling state of the vehicle detected by a traveling state detection device,
A navigation device that holds road information for guiding driving of the vehicle and can detect the current position of the vehicle;
An intersection position search means for searching for the position of the shortest intersection at the shortest forward position from the road information when the vehicle is stopped;
An intersection distance calculation means for calculating a distance from the current position to the shortest intersection;
Based on the distance calculated by the intersection distance calculating means, a forward vehicle number estimating means for estimating the number of forward vehicles included between the current position and the shortest intersection;
When the vehicle is in a running state, the road information, the number of forward vehicles estimated by the forward vehicle number estimating means, and the inter-vehicle distance selecting means for selecting the inter-vehicle distance from the current speed;
The appropriate inter-vehicle distance at the current speed is compared with the inter-vehicle distance selected by the inter-vehicle distance selecting means, and the gear position is controlled according to the second control pattern when the appropriate inter-vehicle distance is not maintained. And a control pattern instruction means for instructing to do so.
[0008]
According to a second aspect of the present invention, in the first aspect, the inter-vehicle distance selecting means includes a correspondence table of the number of road lanes, the traveling speed and the number of the preceding vehicles, and the inter-vehicle distance, and the inter-vehicle distance corresponding to the traveling speed. The gist is to select the inter-vehicle distance by searching.
[0009]
In the configuration of claim 3, in claim 1 or 2, the road information includes information on the number of lanes and the presence or absence of traffic lights at the intersection for each road between the intersections in the road including the road type and the intersection. It is a summary.
[0010]
[Action]
In the configuration of the first aspect, when the vehicle is stopped by the traffic light, the intersection position search means searches the road information for the position of the shortest intersection at the shortest forward position. Then, the intersection distance calculation means calculates the distance from the current position to the shortest intersection, and based on the calculated distance, when the current position is within a preset intersection area, the number of vehicles ahead estimation means The number of forward vehicles included between the current position and the shortest intersection, that is, the number of vehicles stopped by a traffic light in front of the vehicle is estimated.
When the vehicle shifts to the running state, the inter-vehicle distance selecting means selects the inter-vehicle distance based on the road information, the number of forward vehicles estimated by the forward vehicle number estimating means, and the current speed. Then, the control pattern instruction means compares the appropriate inter-vehicle distance at the current speed with the inter-vehicle distance selected by the inter-vehicle distance selection means, and when the proper inter-vehicle distance is not maintained, By instructing to control the shift speed according to the second control pattern for selecting a low shift speed and making the engine brake easy to operate, the vehicle can travel safely. Here, some automatic transmissions have a structure in which the engine brake is effective only at the third speed and the fourth speed in the so-called D range, but here, it is effective at all speeds.
[0011]
Further, in the configuration of claim 2, the inter-vehicle distance selecting means searches the inter-vehicle distance corresponding to the traveling speed from the correspondence table of the number of road lanes, the traveling speed and the number of vehicles ahead, and the inter-vehicle distance. Is selected.
[0012]
Further, in the configuration of claim 3, the road information includes information on the number of lanes and the presence or absence of traffic lights at the intersection for each road between the intersections in the road type and road including the intersection. The road type, the number of lanes, etc. can be searched from the information.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a vehicle control mechanism according to an embodiment of the present invention. The vehicle includes a vehicle navigation device 10 that detects the position of the vehicle and provides route guidance, and an automatic control unit 20 that holds a plurality of control patterns and controls the automatic transmission 60 by selecting an optimal control pattern. And an engine control unit 30 for controlling the engine 50.
[0014]
The navigation device 10 receives a radio wave from an artificial satellite via an antenna 12 using a GPS (global positioning system), calculates a current position, reads out map data recorded in the CD ROM 14, and displays the current position on the map. Identify the location. Furthermore, as will be described later, data relating to a road, a traffic light, etc. that are proceeding and the current position are sent to the automatic control unit 20.
[0015]
Engine control unit 30 provides a signal of the throttle opening from the throttle sensor 40, an engine speed other (coolant temperature, 0 ₂ sensor signals, etc.) from the engine 50 based on a, a fuel injection command to the engine 50 Then, the engine 50 is controlled.
[0016]
The automatic control unit 20 gives a gear shift command to the automatic transmission 60 according to the selected control pattern based on the throttle opening signal from the throttle sensor 40 and the vehicle speed from the automatic transmission 60.
[0017]
Here, a plurality of control patterns (shift maps) held in the automatic control unit 20 will be described with reference to FIG. FIG. 2A shows a normal mode control pattern that suppresses downshifting even when the throttle opening is high and maintains a relatively high shift speed at a low vehicle speed. FIG. 2B shows a control pattern in a downshift mode in which a downshift is performed even when the throttle opening is low and a relatively low gear stage is maintained at a high vehicle speed.
[0018]
2A and 2B, the horizontal axis represents the vehicle speed, and the vertical axis represents the throttle opening. As shown in FIG. 2A, in the normal mode, for example, the downshift from the second speed to the first speed is performed when the vehicle speed is relatively low and the throttle opening is large. Similarly, the downshift from the 3rd speed to the 2nd speed and the 4th speed to the 3rd speed is performed when the vehicle speed is relatively low and the throttle opening is large. The automatic control unit 20 controls the rotation of the engine 50 by suppressing unnecessary downshifts and upshifts by giving gear shift commands to the automatic transmission 60 based on the shift map (control pattern) set in this way. Keeping the numbers low gives the driver a comfortable cruising feeling and reduces fuel consumption. This normal mode is used when the vehicle travels on a free general road or highway with a high cruise speed and a low frequency of acceleration / deceleration.
[0019]
In the downshift mode as shown in FIG. 2B, for example, the downshift from the second speed to the first speed is performed even when the vehicle speed is relatively high and the throttle opening is low. The downshift from the 3rd speed to the 2nd speed and the 4th speed to the 3rd speed is performed in the same manner. The automatic control unit 20 actively shifts down by giving a gear shift command to the automatic transmission 60 based on this shift map, and keeps the engine 50 high so that the engine brake is effective. It is better to start deceleration at the same time as the throttle opening decreases, and to shift down immediately when the throttle opening increases so that acceleration can be performed in a short time. In this downshift mode, while traveling on a congested road where it is difficult to maintain an appropriate inter-vehicle distance, deceleration is started at the same time as the accelerator pedal is returned to prevent rear-end collision and enable safe traveling. This normal mode is also suitable when traveling on a mountain road where acceleration / deceleration is frequently performed.
[0020]
In this embodiment, a change-over switch (not shown) is provided on the operation panel of the driver's seat, and the normal mode and the shift-down mode can be selected by this change-over switch. Further, the changeover switch can be set to automatic switching. When automatic switching is set, the automatic control unit 20 will select the appropriate one in the normal mode and the downshift mode as described later. It is configured to select and give a gear shift command to the automatic transmission 60.
[0021]
Next, the contents of the map data recorded on the CD ROM 14 of the navigation device 10 will be described. In this map data, in addition to general map data corresponding to a road map, detailed data regarding road conditions is held. The details of the data will be described with reference to FIG. As map data, the coordinates of the intersections A-1, A-2, A-3,... Shown in FIG. 3 are held, and the intersections A-1, A-2, A-3,. The connecting roads are identified by numbers. For example, the connecting road between the intersection B-1 and the intersection B-2 is numbered X21, and the connecting road between the intersection B-2 and the intersection B-3 is numbered X22. Yes. The number of lanes is held for each conclusion road. FIG. 4 is a diagram showing in detail the combined roads X21 and X22 shown in FIG. Here, since the combined road X21 has two lanes on one side and the combined road X22 has one lane on one side, the number of lanes 2 is stored for the combined road X21 and the number of lanes 1 is stored for the combined road X22. In addition, the length of each combined road is also stored. Furthermore, the presence or absence of traffic lights at each intersection is held. For example, there is a signal for the intersection B-2, while no signal is held for the intersection C-3 shown in FIG. Further, at intersections where signals are present, times such as red, yellow, blue, and right turn of traffic lights are recorded. For example, for the intersection B-2, the time for red, yellow, blue, right turn, etc. for the traffic light B-2-Y related when traveling from the intersection C-2 side is similarly the intersection B-1 side. Times such as red, yellow, blue, right turn, etc. are maintained for the traffic light B-2-X when proceeding from. Furthermore, the type of highway, toll road, general road, etc. is held for each road.
[0022]
Next, an inter-vehicle distance estimation map held in the automatic control unit 20 will be described with reference to FIG. The inter-vehicle distance estimation map is created based on a value obtained by actually measuring the inter-vehicle distance x when n vehicles are traveling on a road with the number of lanes L at a speed v as shown in FIG. . For example, as shown in FIG. 4, the inter-vehicle distance x in each speed band is measured when n vehicles whose signals have stopped at an intersection B-2 are traveling on a combined road X22 on one lane on one side. Here, when 0 ≦ n <8 vehicles are stopped at the intersection and the vehicle is traveling at a speed of 20 km per hour belonging to the band of 0 <v <25, the inter-vehicle distance is measured to be x1, and 25 When traveling at a speed of 30 km per hour belonging to a band of ≦ v <35, a map for estimating the inter-vehicle distance is created based on the result of measuring that the inter-vehicle distance is x2.
[0023]
The automatic control unit 20 further holds a map of the correspondence relationship between the vehicle speed and the appropriate inter-vehicle distance (determination inter-vehicle distance) as shown in FIG. 5, for example, 30 m during traveling at 30 km / h, At 50 km / h, 55 m is configured to be an appropriate inter-vehicle distance. That is, based on this map, an appropriate inter-vehicle distance at the speed can be immediately obtained from the speed of the own vehicle.
[0024]
Subsequently, the control operation of the shift stage of the automatic transmission 60 by the automatic control unit 20 will be described with reference to FIGS. 4 and 6. In the above description, the method for measuring the inter-vehicle distance has been described with reference to FIG. 4, but here, FIG. 4 is assumed to indicate the current traveling state of the vehicle. FIG. 6 is a flowchart showing a main routine of the process. First, the automatic control unit 20 reads the vehicle speed v from a vehicle speed sensor (not shown) attached to the automatic transmission 60, and also reads the road type of the currently running road from the navigation device 10 (S10). Subsequently, it is determined whether the road type is a road without a traffic signal such as an expressway, an urban expressway, a toll road, or the like (S12). If the road type is an expressway (S12 is Yes), it is shown in FIG. A normal control pattern is selected (S22). On the other hand, if the road type is a general road with an intersection (No in S12), it is determined whether the vehicle is currently stopped (vehicle speed v = 0) (S14).
[0025]
Here, as shown in FIG. 4, when the vehicle is stopped by the traffic light at the intersection B-2 (Yes in S14), the current road number i (here, X21) is read. Then, it is determined by searching the map data whether there is a traffic light at the intersection (S18). Here, since the traffic light is provided at the intersection B-2 (Yes in S18), the process proceeds to step 20, and the number n of vehicles ahead is estimated. For example, when the vehicle stops in the vicinity of the intersection C-3, the determination of the presence of the traffic signal in Step 18 is No, and the process proceeds to Step 22.
[0026]
Here, the process of estimating the number n of front vehicles (S20) will be described in detail with reference to FIG. 7 showing a subroutine of the process. First, the automatic control unit 20 reads the current position coordinates of the own vehicle, the position coordinates of the intersection B-2, and the number of lanes M of the road X21 where the current signal is stopped from the navigation device 10. Based on the position coordinates of the own vehicle and the position coordinates of the intersection B-2, the distance d from the own vehicle to the intersection B-2 is calculated (S54). Thereafter, the number n of vehicles stopped ahead is calculated from the equation n = M × INT (d / ao) (S56). Here, M is the number of lanes (here 2), INT is rounded off, ao is the exclusive distance of one vehicle (for example, the length of one vehicle is 4 m, and the inter-vehicle distance of 1 m is placed at the front and back. If it stops, 6m) is shown. The number of vehicles ahead is estimated by the above processing (S20), and the process proceeds to Step 22.
[0027]
When the intersection B-2 becomes a green light and the vehicle starts to travel, the determination of whether the vehicle speed v = 0 in Step 14 is No, the current traveling road number j is taken in (S26), and the vehicle stops at the intersection. It is determined whether the road number is the straight road next to the road (S28). Here, when the vehicle stops on the combined road X21 in front of the intersection B-2 shown in FIG. 4 and travels straight on the combined road X22, it is determined to be the next straight road on the combined road X21. The determination in step 28 is Yes. On the other hand, after stopping at the combined road X21 and turning right at the intersection B-2 and traveling on the combined road Y22, the vehicle travels on a road different from the straight road. The determination is no and the process proceeds to step 22. Here, the following description will be continued on the assumption that the vehicle is stopped on the combined road X21 and is traveling straight on the combined road X22.
[0028]
Next, the length L of the currently traveling road (joint road X22) is read by searching the map data described above (S30). And it is judged whether this road length L is longer than the preset length Lo (S32). Here, if the road length L is shorter than Lo (No in S32), it is difficult to estimate the inter-vehicle distance described later, and the routine proceeds to step 24. On the other hand, when the road length L is longer than Lo (Yes in S32), the inter-vehicle distance x is estimated by searching the inter-vehicle distance correspondence table (map) described above with reference to FIG. 8 (S34). For example, the number of vehicles stopped at the intersection B-2 estimated in step 20 is estimated as seven, and the number of lanes M of the currently traveling road X22 is one lane on one side and the current vehicle speed is 30 km / h. In this case, the value of x2 is estimated as the inter-vehicle distance. Subsequently, the determined inter-vehicle distance at the current vehicle speed v, that is, an appropriate inter-vehicle distance x ^* when traveling at the vehicle speed v is selected based on the map described above with reference to FIG. 8 (S36). Thereafter, it is determined whether the estimated inter-vehicle distance x is smaller than the determined inter-vehicle distance x ^* (S38). Here, when the estimated intervehicular distance x is greater than the determined intervehicular distance x ^* (No in S38) and the proper intervehicular distance is maintained, the routine proceeds to step 22 and the normal control shown in FIG. A pattern is selected, and the automatic transmission 60 is controlled based on the normal control pattern (S24). That is, when a sufficient inter-vehicle distance is maintained, unnecessary downshifting and sit-up are suppressed, and the engine 50 is kept at a low speed, thereby giving a comfortable feeling to the driver and reducing fuel consumption.
[0029]
On the other hand, when the estimated intervehicular distance x is smaller than the determined intervehicular distance x ^* (Yes in S38) and the proper intervehicular distance is not maintained, the process proceeds to step 40, and the downshift control pattern shown in FIG. And the automatic transmission 60 is controlled based on the control pattern (S24). In other words, even when the throttle opening is small and the vehicle speed is high, selecting a relatively low shift speed improves the engine brake so that the deceleration starts as soon as the foot is released from the accelerator pedal. Even if the inter-vehicle distance is short, it is possible to travel safely without a rear-end collision. In addition, when the accelerator is stepped on, it will immediately shift down so that it can accelerate quickly.
[0030]
In the above-described embodiment, processing such as estimation of the inter-vehicle distance is performed on the automatic control unit 20 side, but this processing is performed by the navigation device 10 and control pattern switching is performed from the navigation device 10 side. It can also be configured to instruct the unit 20 side. In the above-described embodiment, the inter-vehicle distance is estimated using the number of lanes as a parameter so that the change in the number of lanes for each combined road can be handled. Needless to say, it is possible to estimate the inter-vehicle distance while ignoring the number of lanes.
[0031]
Furthermore, in the above-described embodiment, the case where the automatic control unit 20 has two types of control patterns, that is, a normal mode control pattern and a shift down control pattern, is described as an example. The present invention can also be suitably applied to cases having the above control pattern.
[0032]
【effect】
As described above, according to the automatic transmission control device for a vehicle of the present invention, the control pattern can be switched according to the degree of traffic congestion. In other words, when it is difficult to maintain an appropriate intervehicular distance due to traffic jams, the control pattern for downshifting is automatically selected to make the engine brake easier to operate so that deceleration starts as soon as you release the accelerator pedal. Even if is short, it is possible to perform safe driving without rear-end collision. On the other hand, when a sufficient inter-vehicle distance can be ensured, a comfortable cruise can be made possible by suppressing unnecessary downshifts and upshifts and keeping the engine speed low.
[Brief description of the drawings]
FIG. 1 is a block diagram of a navigation device, an automatic control unit, and an engine control unit according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram showing a control pattern by an automatic control unit.
FIG. 3 is an explanatory diagram showing the contents of map data.
FIG. 4 is an explanatory diagram showing a situation of a road on which a vehicle is traveling.
FIG. 5 is an explanatory diagram showing a relationship between a vehicle speed and an appropriate inter-vehicle distance.
FIG. 6 is a flowchart showing a main routine of the automatic control unit.
7 is a flowchart showing a subroutine of a front vehicle number n estimation process shown in FIG. 6. FIG.
FIG. 8 is a table showing the relationship between the number of vehicles and the inter-vehicle distance.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Navigation apparatus 20 Automatic control unit 30 Engine control unit 40 Throttle sensor 50 Engine 60 Automatic transmission 70 Accelerator pedal

Claims (3)

Based on one of the first control pattern for selecting a high shift speed at a low vehicle speed and the second control pattern for selecting a low shift speed at a high vehicle speed, the travel state of the vehicle detected by the travel state detection device is determined. An automatic transmission control device for a vehicle that controls a shift stage of an automatic transmission in response,
A navigation device that holds road information for guiding driving of the vehicle and can detect the current position of the vehicle;
An intersection position search means for searching the position of the shortest intersection at the shortest forward position from the road information when the vehicle is stopped;
An intersection distance calculation means for calculating a distance from the current position to the shortest intersection;
Based on the distance calculated by the intersection distance calculating means, a forward vehicle number estimating means for estimating the number of forward vehicles included between the current position and the shortest intersection;
When the vehicle is in a running state, the road information, the number of forward vehicles estimated by the forward vehicle number estimating means, and an inter-vehicle distance selecting means for selecting an inter-vehicle distance from the current speed;
The appropriate inter-vehicle distance at the current speed is compared with the inter-vehicle distance selected by the inter-vehicle distance selecting means, and the gear position is controlled according to the second control pattern when the appropriate inter-vehicle distance is not maintained. And a control pattern indicating means for instructing the automatic transmission control device for a vehicle. The inter-vehicle distance selecting means includes a correspondence table of the number of road lanes, the traveling speed and the number of vehicles ahead, and the inter-vehicle distance, and selects the inter-vehicle distance by searching the inter-vehicle distance corresponding to the traveling speed. The automatic transmission control device for a vehicle according to claim 1. 3. The vehicle according to claim 1, wherein the road information includes information on the number of lanes and the presence / absence of a traffic signal at an intersection for each road between intersections in a road including a road type and an intersection. Automatic transmission control device.

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