JP2018017370A - Automatic shift control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress deterioration of exhaust emission after gear shift.SOLUTION: An automatic shift control device includes: a fuel consumption map storage part 6 for storing a fuel consumption map which regulates a relation between a parameter indicating an engine operation state and a fuel consumption rate; an exhaust gas component map storage part 6 for storing an exhaust gas component map which regulates a relation between the parameter and the discharge amount of a predetermined exhaust gas component; a candidate gear stage determination part 6 for determining candidate gear stages which are the candidates of the shift destination gear stage by using at least one of the fuel consumption map and the exhaust gas component map; and a shift destination gear stage determination part 6 for determining the gear stage in which the fuel consumption rate level and the exhaust gas component discharge amount level become integrally the most appropriate as the shift destination gear stage, out of the determined candidate gear stages, by using the fuel consumption map and the exhaust gas component map.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an automatic transmission control device, and more particularly to an automatic transmission control device for automatically shifting a transmission of a vehicle.

  As such an automatic shift control device, an automatic shift control device that shifts to a gear stage that minimizes the fuel consumption rate (also referred to as fuel efficiency) is known.

JP-A-9-126310

  However, even if such automatic shift with priority on fuel consumption is performed, the amount of exhaust gas components such as smoke increases after the shift, and exhaust emissions may deteriorate.

  Accordingly, the present invention has been made in view of such circumstances, and an object thereof is to provide an automatic transmission control device capable of suppressing deterioration of exhaust emission after a shift.

According to one aspect of the invention,
A fuel consumption map storage unit that stores a fuel consumption map that defines a relationship between a parameter representing an engine operating state and a fuel consumption rate;
An exhaust gas component map storage unit that stores an exhaust gas component map that defines a relationship between the parameter and a predetermined exhaust gas component emission amount;
Using at least one of the fuel consumption map and the exhaust gas component map, a candidate gear stage determination unit that determines a candidate gear stage that is a candidate for a shift destination gear stage;
Using the fuel consumption map and the exhaust gas component map, a gear stage in which the fuel consumption rate level and the exhaust gas component emission level are best overall is selected from the determined candidate gear speeds. A shift destination gear stage determining unit that determines the stage;
An automatic transmission control device characterized by comprising:

  Preferably, the exhaust gas component is at least one of smoke and NOx.

  Preferably, a shift control unit that shifts the transmission to the determined shift destination gear stage is further provided.

According to another aspect of the invention,
An exhaust gas component map storage unit that stores an exhaust gas component map that defines a relationship between a parameter representing an engine operating state and an emission amount of a predetermined exhaust gas component;
Using the exhaust gas component map, a candidate gear stage determination unit that determines a candidate gear stage that is a candidate for the shift destination gear stage;
A shift destination gear stage determining unit that determines, as the shift destination gear stage, a gear stage having the best exhaust gas component emission amount level from the determined candidate gear stages using the exhaust gas component map;
An automatic transmission control device characterized by comprising:

  According to the present invention, an excellent effect is exhibited in that deterioration of exhaust emission after a shift can be suppressed.

It is the schematic of the automatic transmission control apparatus of the vehicle which concerns on basic embodiment of this invention. A fuel consumption map is shown. Shows the smoke map. A NOx map is shown. It is a graph which shows the fuel consumption level, smoke level, NOx level, etc. about each gear stage.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic diagram of an automatic transmission control device for a vehicle according to a basic embodiment of the present invention. The automatic transmission control device of this embodiment is for automatically changing the speed of a multi-stage transmission 3 connected to a diesel engine 1 via a clutch 2. Although the transmission 3 has 12 forward speeds in this embodiment, the number of speeds is arbitrary.

  The engine 1 is controlled by an engine control unit (ECU) 6 that forms an engine control unit or an engine controller. The ECU 6 actually detects the output from the engine rotation sensor 7 for detecting the engine speed (unit: rpm) and the accelerator opening sensor 8 for detecting the operation amount (accelerator opening) of the accelerator pedal 5. The engine rotation speed and the accelerator opening (corresponding to the engine load) are detected, and the fuel injection amount and the fuel injection timing are controlled mainly based on these to control the engine output.

  The clutch 2 and the transmission 3 are controlled by a transmission control unit (TMCU) 9 that forms a transmission control unit or a transmission controller. The ECU 6 and the TMCU 9 are connected to each other via a bus cable or the like and can communicate with each other. The ECU 6 and the TMCU 9 may be integrated and the engine 1, the clutch 2, and the transmission 3 may be controlled by a single control unit (control unit or controller).

  A clutch actuator 10 is connected to the clutch 2. The TMCU 9 outputs a signal to the clutch actuator 10 and operates the clutch actuator 10 to automatically connect and disconnect the clutch 2. In this embodiment, the clutch 2 can be manually connected / disconnected by the clutch pedal 11.

  A gear shift unit (GSU) 12 is connected to the transmission 3. The TMCU 9 outputs a signal to the GSU 12 and operates the GSU 12 to automatically shift the transmission 3. The transmission 3 is provided with a gear position sensor 23 for detecting the gear position, and the detection value of the gear position sensor 23 is transmitted to the TMCU 9. In the present embodiment, manual shift of the transmission 3 by the shift lever device 29 is also possible.

  When the transmission 3 is automatically shifted, the TMCU 9 first operates the clutch actuator 10 to disengage the clutch 2, and then operates the GSU 12 to execute the shift operation (gear release, gear in) of the transmission 3. When completed, the clutch actuator 10 is operated again to connect the clutch 2.

  On the other hand, an oxidation catalyst 16, a particulate filter (referred to as DPF) 17, a NOx catalyst 18, and an ammonia oxidation catalyst 19 are provided in the exhaust passage 15 of the engine 1 in order from the upstream side.

The oxidation catalyst 16 oxidizes and purifies unburned components (hydrocarbon HC and carbon monoxide CO) in the exhaust gas, heats the exhaust gas with the reaction heat at this time, and heats the NO in the exhaust gas to NO. Oxidizes to ₂ . The DPF 17 is a so-called continuous regeneration type DPF with a catalyst, which collects particulate matter (PM) in the exhaust gas and continuously burns and removes the collected PM. The NOx catalyst 18 is a selective reduction type NOx catalyst (SCR), and reduces NOx in the exhaust gas using ammonia resulting from the urea water added from the addition valve 20 as a reducing agent. The ammonia oxidation catalyst 19 oxidizes and purifies excess ammonia discharged from the NOx catalyst 18.

  The addition valve 20 is controlled by the ECU 6. Further, a differential pressure sensor 21 for detecting the differential pressure on the upstream and downstream sides of the DPF 17 is provided. The ECU 6 estimates the PM accumulation amount in the DPF 17 from the output of the differential pressure sensor 21. The PM accumulation amount can also be estimated based on the travel distance of the vehicle, the engine operation time, the fuel injection amount integrated value, and the like.

  Next, the shift control in this embodiment will be described. Such shift control is mainly executed by the ECU 6 and the TMCU 9. The ECU 6 and the TMCU 9 are collectively referred to as “control unit”.

  The ECU 6 stores a fuel consumption map that defines a relationship between a parameter representing an engine operating state and a fuel consumption rate. An example of this fuel consumption map is shown in FIG. The horizontal axis represents the engine speed NE (rpm), and the vertical axis represents the engine torque T (Nm). The engine torque T is an output torque of the engine 1 and corresponds to the net average effective pressure Pme. That is, in this embodiment, the engine speed NE and the engine torque T are used as parameters representing the engine operating state.

  A plurality of lines a indicate equal fuel consumption lines, and numerals 1, 2, 3, and 4 attached to the respective equal fuel consumption lines a indicate fuel consumption levels. As the fuel consumption level decreases, the fuel consumption rate decreases, which is favorable from the viewpoint of fuel consumption. For example, the fuel consumption level 1 is lower than the fuel consumption level 4 and the fuel consumption rate is better. Line b is the maximum torque line. The maximum torque here means the torque generated by the engine when the accelerator opening is substantially fully open.

  Although the same applies to the following maps, the shape of the equal fuel consumption line a in the fuel consumption map is merely a conceptual drawing drawn for convenience in order to explain the gist of the present embodiment, and is not necessarily that of an actual engine. Note that they do not match.

  In addition to the fuel consumption map, the ECU 6 also stores an exhaust gas component map that defines a relationship between a parameter representing the engine operating state and a predetermined exhaust gas component emission amount. In the present embodiment, smoke and NOx are used as exhaust gas components. However, the number and type of exhaust gas components can be arbitrarily selected, and in particular, exhaust gas components that are subject to exhaust gas regulation can be suitably selected. For example, the exhaust gas component can be only one of smoke or only one of NOx. An exhaust gas component map corresponding to smoke is referred to as a smoke map, and an exhaust gas component map corresponding to NOx is referred to as a NOx map.

  An example of the smoke map is shown in FIG. The horizontal axis, the vertical axis, and the maximum torque line b are the same as those in the fuel consumption map.

  A plurality of lines d indicate equal smoke lines, and numerals 1, 2, 3, and 4 attached to the equal smoke lines d indicate smoke levels. As described above, the smaller the smoke level, the smaller the smoke and the better from the point of view of smoke. For example, smoke level 1 has less smoke and is better than smoke level 4.

  An example of the NOx map is shown in FIG. The horizontal axis, the vertical axis, and the maximum torque line b are the same as those in the fuel consumption map.

  A plurality of lines e indicate equal NOx lines, and numerals 1, 2, 3, and 4 attached to the respective equal NOx lines e indicate NOx levels. As the NOx level decreases, NOx decreases, which is favorable from the viewpoint of NOx. For example, NOx level 1 is better than NOx level 4 with less NOx.

  Of these three maps, at least one of the maps is used to determine a candidate gear stage that is a candidate for the shift destination gear stage. In this embodiment, the candidate gear stage is determined using the fuel consumption map, so refer to FIG. Here, the case of upshifting will be described, but it will be understood that the same method or logic can be applied to downshifting.

  A plot N in the figure shows the actual engine speed NE and the engine torque T at the current time point when the vehicle is traveling in the current gear stage N. The actual engine rotation speed NE is detected by the engine rotation sensor 7. The actual engine torque T is estimated by the ECU 6 based on the actual engine speed NE and the actual accelerator opening AC detected by the accelerator opening sensor 8.

  Based on this plot N, candidate gear stages (N + 1, N + 2 in the present embodiment) when the gear is shifted up are determined. Candidate gear stages N + 1 and N + 2 are gear stages on an equal output line (or equal horsepower line) c passing through the plot N. That is, at least after the upshifting, the vehicle does not stall and it is necessary to ensure the same engine output (horsepower) as that in the current state in order to travel normally in the current state. Therefore, a gear stage that is higher than the current gear stage N and does not exceed the maximum torque line b among the gear stages on the equal output line c passing through the plot N is determined as a candidate gear stage.

Specifically, the current engine output P _N (kW) is obtained by multiplying the current engine torque T _N corresponding to the plot N by the engine speed NE _N (and a necessary coefficient). Then, the engine speed NE _{N + 1} is calculated from the current engine speed NE _N and the gear ratio of the gear stage N + 1 when it is assumed that the gear has been shifted up to the gear stage N + 1 that is one stage higher than the current gear stage N. The current engine output _PN is divided by the engine speed NE _{N + 1} (and necessary coefficient) after the upshift to obtain the engine torque T _{N + 1} after the upshift. From the engine speed NE _{N + 1} and the engine torque T _{N + 1} after the shift up, a plot N + 1 corresponding to the gear stage N + 1 is determined.

  By repeating such calculation for the gear stages N + 2, N + 3..., One or a plurality of candidate gear stages on the equal output line c and not exceeding the maximum torque line b are determined. In the illustrated example, as a result, two candidate gear stages N + 1 and N + 2 are determined.

  The plots N, N + 1, N + 2 obtained from the fuel consumption map in this way and the iso-output line c are similarly applied to the smoke map and the NOx map. In the three maps of FIGS. 2 to 4, the plots N, N + 1, N + 2 and the iso-output line c appear at the same position.

  Next, for each plot N, N + 1, N + 2, that is, for each gear, the ECU 6 determines the fuel consumption level, smoke level, and NOx level from each map. The result is shown in FIG.

  As shown in FIG. 5, the results of N = 4.2, N + 1 = 2.2, and N + 2 = 0.8 are obtained for the fuel efficiency. Similarly, for smoke, N = 1.3, N + 1 = 2.7, N + 2 = 4.2, and for NOx, N = 1.2, N + 1 = 0.8, N + 2 = 2.5. Is obtained.

  Next, the total value of the fuel consumption level, smoke level and NOx level for each gear stage is obtained. As for the total value, N = 6.7, N + 1 = 5.7, and N + 2 = 7.5 are obtained. When the fuel consumption level is Lf, the smoke level is Ls, and the NOx level is Ln, the total value T is obtained from the following equation.

  Instead of or in addition to the total value, the average value of fuel consumption level, smoke level and NOx level, especially arithmetic average value (also called arithmetic average value or simple average value) μ for each gear stage, You may ask for.

  As shown in FIG. 5, the arithmetic average values are N = 2.23, N + 1 = 1.9, and N + 2 = 2.5.

  As described above, regarding the fuel consumption, smoke and NOx, the smaller the numerical value of each level, the better. Therefore, it can be said that the smaller the total value or arithmetic mean value is, the better the fuel consumption, smoke and NOx are from a comprehensive viewpoint.

  Therefore, in the present embodiment, the candidate gear stage having the minimum total value or arithmetic average value is determined by the ECU 6 as a shift destination gear stage that is a shift destination gear stage from the current gear stage. According to the result of FIG. 5, the gear stage N + 1 has the smaller total value and arithmetic mean value among the gear stages N + 1 and N + 2. Therefore, the gear stage N + 1 is determined as the shift destination gear stage.

  Note that the current gear stage N may be included in the candidate gear stage. In this case as well, the gear stage N + 1 has the smallest total value and arithmetic mean value among the gear stages N, N + 1, and N + 2. Therefore, the gear stage N + 1 is determined as the shift destination gear stage.

  As described above, in the present embodiment, the fuel consumption level, the smoke level, and the NOx level are determined to be the best from the candidate gear stages N, N + 1, N + 2 determined using the fuel consumption map, the smoke map, and the NOx map. Such a gear stage is determined as a shift destination gear stage.

  When the shift destination gear stage is thus determined, the TMCU 9 operates the clutch actuator 10 and the GSU 12 to shift the transmission 3 to the determined shift destination gear stage. In this example, the transmission 3 is shifted from the current gear stage N to the shift destination gear stage N + 1.

  The ECU 6 and the TMCU 9 perform the above-described calculation every predetermined calculation cycle τ (for example, 10 ms), and change gears toward the gear stage whenever the gear stage at which the total value or the arithmetic mean value is minimized is changed. Perform the action. As a result, the fuel economy level, the smoke level, and the NOx level can always be best balanced.

  Here, the further effect of this embodiment is demonstrated with the comparative example before reaching the idea of this invention.

  In the comparative example, the exhaust gas component is not taken into consideration, and the shift control is performed exclusively from the viewpoint of fuel consumption only. In this case, from the result of FIG. 5, the gear stage having the minimum fuel consumption level is N + 2, so the gear stage is shifted up to N + 2.

  However, in this case, the smoke level and the NOx level are worse than the current gear stage N. On the other hand, in the present embodiment, the gear is shifted up to the gear stage N + 1 in consideration of the smoke and NOx levels, so that it is possible to suppress an increase in exhaust gas component emission after the shift up and to suppress deterioration in exhaust emission. it can. In other words, it is possible to shift up to a gear stage in which the fuel consumption and the exhaust gas component emission amount are optimally balanced.

  By doing so, since the smoke discharge amount can be suppressed, the regeneration frequency of the DPF 17 can also be reduced. That is, when the estimated amount of accumulated PM in the DPF 17 exceeds a predetermined amount, DPF regeneration control for forcibly burning and removing the deposited PM by performing post injection or the like is performed by the ECU 6, and the frequency of this DPF regeneration control is set. Can be reduced. Since the frequency of additional fuel injection such as post injection is reduced, it is advantageous in terms of fuel consumption. Further, since the NOx emission amount can be suppressed, the consumption amount of urea water necessary for NOx reduction can also be reduced.

  In the above embodiment, only the case of shifting up from the current gear stage N has been described, but the shift destination gear stage may be determined including the downshift side. In this case, the shift-down-side candidate gear stages N-1, N-2,... Are also determined based on the plot N, and the best shift destination gear is selected from among the shift-up and shift-down candidate gear stages. The gear is determined, and the gear is shifted to the shift destination gear. If the current gear stage N is the best, no gear shift is performed and the gear stage is held at the current gear stage N.

  As understood from the above description, the ECU 6 constitutes a fuel consumption map storage unit, an exhaust gas component map storage unit, a candidate gear stage determination unit, and a shift destination gear stage determination unit according to the present invention. The TMCU 9, the clutch actuator 10 and the GSU 12 constitute a shift control unit according to the present invention.

  Next, another embodiment will be described.

  First, a first other embodiment will be described. For example, although the PM accumulation amount of the DPF 17 is smaller than a predetermined amount that determines the regeneration timing, it may be advantageous to delay the regeneration timing by suppressing the smoke discharge amount when approaching it. Therefore, in this case, it is preferable to calculate the weighted average value by weighting the target smoke larger than the other among the fuel consumption, smoke and NOx, and to determine the shift destination gear stage based on the weighted average value. .

  In this case, the weighted average value μw is obtained from the following equation.

  wf is a weighting factor for the fuel consumption level Lf, ws is a weighting factor for the smoke level Ls, and wn is a weighting factor for the NOx level Ln. wf + ws + wn = 1, 0 <wf <1, 0 <ws <1, 0 <wn <1.

  Here, a case will be described in which the PM accumulation amount of the DPF 17 is less than a first predetermined amount that determines the regeneration timing, and is slightly more than a second predetermined amount that is slightly smaller than that. At this time, the smoke is weighted more than others, in other words, ws> wf, wn. For example, as shown in FIG. 5, wf = 1/5, ws = 3/5, and wn = 1/5. Before this happens, the shift destination gear stage is determined based on the arithmetic mean value, and the (apparent) weighting factors at this time are wf = 1/3, ws = 1/3, and wn = 1/3. .

  Then, as shown in FIG. 5, the weighted average values are N = 1.86, N + 1 = 2.22, and N + 2 = 3.18. In this example, since the current gear stage N is the minimum weighted average value, the gear stage is held in the current gear stage N. However, if the gear stage with the minimum weighted average value is other than the current gear stage N, the transmission 3 is controlled to shift to that gear stage.

  Similarly, in the case where it is desired to suppress the NOx emission amount because the remaining amount of urea water is less than a predetermined value, the NOx weighting factor wn is increased from the other weighting factors wf and ws, and the same shift control is performed. It can be performed. Further, when it is desired to suppress the fuel consumption because the remaining amount of fuel is small or less than the predetermined value, the same shift control can be performed by increasing the fuel consumption weight coefficient wf over the other weight coefficients ws and wn.

  Next, a second other embodiment will be described. In the basic embodiment described above and the first other embodiment, the shift control is performed in consideration of the fuel consumption in addition to the exhaust gas component. On the other hand, in this embodiment, the shift control is performed in consideration of only the exhaust gas component without considering the fuel consumption. In this case, the fuel efficiency map of FIG. 2 is not used, and the candidate gear stage and the shift destination gear stage are determined based only on the smoke map of FIG. 3 and the NOx map of FIG. Also according to the present embodiment, it is possible to suppress the deterioration of exhaust emission after shifting.

  In this case, the ECU 6 forms an exhaust gas component map storage unit that stores a smoke map and a NOx map that define the relationship between the engine rotational speed NE and the engine torque T, and the smoke and NOx emissions. The ECU 6 serves as a candidate gear stage determination unit that determines a candidate gear stage using at least one of the smoke map and the NOx map. Further, the ECU 6 uses the smoke map and the NOx map to determine a gear position that determines the best smoke and NOx emission level as a gear shift destination gear position from among the determined candidate gear speeds. Make a decision.

  As described above, the exhaust gas component may be only one of smoke. In this case, the transmission is shifted one after another so that the smoke emission level is the best and the minimum. Further, the exhaust gas component may be only one of NOx. In this case, the transmission is shifted one after another so that the NOx emission level is the best and the minimum.

  Although the embodiments of the present invention have been described in detail above, various other embodiments of the present invention are conceivable.

  The configurations of the above-described embodiments can be combined partially or wholly unless there is a particular contradiction. The embodiment of the present invention is not limited to the above-described embodiment, and includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims. Therefore, the present invention should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present invention.

1 Engine 2 Clutch 3 Transmission 6 Engine Control Unit (ECU)
7 Engine rotation sensor 8 Accelerator opening sensor 9 Transmission control unit (TMCU)

Claims (4)

A fuel consumption map storage unit that stores a fuel consumption map that defines a relationship between a parameter representing an engine operating state and a fuel consumption rate;
An exhaust gas component map storage unit that stores an exhaust gas component map that defines a relationship between the parameter and a predetermined exhaust gas component emission amount;
Using at least one of the fuel consumption map and the exhaust gas component map, a candidate gear stage determination unit that determines a candidate gear stage that is a candidate for a shift destination gear stage;
Using the fuel consumption map and the exhaust gas component map, a gear stage in which the fuel consumption rate level and the exhaust gas component emission level are best overall is selected from the determined candidate gear speeds. A shift destination gear stage determining unit that determines the stage;
An automatic transmission control device comprising: The automatic transmission control device according to claim 1, wherein the exhaust gas component is at least one of smoke and NOx. The automatic shift control device according to claim 1, further comprising a shift control unit that shifts the transmission to the determined shift destination gear stage. An exhaust gas component map storage unit that stores an exhaust gas component map that defines a relationship between a parameter representing an engine operating state and an emission amount of a predetermined exhaust gas component;
Using the exhaust gas component map, a candidate gear stage determination unit that determines a candidate gear stage that is a candidate for the shift destination gear stage;
A shift destination gear stage determining unit that determines, as the shift destination gear stage, a gear stage having the best exhaust gas component emission amount level from the determined candidate gear stages using the exhaust gas component map;
An automatic transmission control device comprising:

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