JP2005106164A - Automatic transmission for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an automatic transmission for a vehicle determining a vehicle state and selecting optimum speed stage at start. <P>SOLUTION: This automatic transmission for the vehicle includes start speed stage determination means selecting the optimum speed stage at start, a control means controlling the start speed stage determination means. The control means is provided with a start speed stage determination means automatically selecting the optimum speed stage at start according to a fuzzy rule with using one condition or a condition combining a plurality of functions of a membership function based on vehicle weight, a membership function based on gradient of a road, and a membership function based on travel history or the like based on speed of the vehicle. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an automatic transmission for a vehicle that automatically selects a gear position.

  In general, in an automatic transmission of a vehicle, the optimum gear stage is selected according to the running condition of the vehicle when traveling, and the vehicle is traveling, and is fixed at a predetermined starting stage when starting. The vehicle is being started.

Japanese Patent Publication No. 6-39223

  In the conventional automatic transmission of a vehicle, the optimum shift speed (starting speed) is not automatically selected at the time of starting, but the vehicle is started with being fixed at a predetermined starting speed. For example, in a large vehicle such as a truck, normally, the second gear is started. If the vehicle is on an uphill road or the weight of the loaded cargo is large, the start gear is intentionally set to 1 according to the judgment of the driver. The vehicle is started by changing to a high gear. However, if the driver himself / herself has not fully grasped the situation of the vehicle, or if there is a misjudgment, when trying to start at the normal start stage, that is, the second speed stage, the size of the cargo weight or the uphill road Due to the gradient, the starting load becomes large, and it may be impossible to start at a normal starting stage.

  Even if the vehicle can start, in the above situation, the half-clutch state at the time of starting becomes long, the energy absorbed by the clutch increases, and the life of the clutch may be shortened. In particular, this effect is significant in dry clutches.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an automatic transmission for a vehicle that determines a vehicle state and selects an optimal gear position when starting.

An automatic transmission for a vehicle according to the present invention that solves the above problems is as follows.
A gear selection means for selecting a gear position of the transmission;
Control means for controlling the gear position selection means,
The control means includes start stage determination means for determining the vehicle state based on the fuzzy rules and selecting an optimum gear position at the start.
In other words, unlike the prior art, when starting the vehicle, the state of the vehicle is judged and the optimum starting gear is selected. For the selection of the shift speed, conventional shift speed selection means for selecting a shift speed during traveling, for example, an electric gear shift unit or the like is used.

An automatic transmission for a vehicle according to the present invention that solves the above problems is as follows.
In the automatic transmission of the vehicle,
The starting stage determining means is a fuzzy rule for determining the vehicle status, and includes at least one condition selected from a membership function based on the weight of the vehicle, a membership function based on the gradient of the roadway, and a membership function based on the vehicle travel history, or a plurality of conditions The optimum gear position is determined using the combined conditions.

An automatic transmission for a vehicle according to the present invention that solves the above problems is as follows.
In the automatic transmission of the vehicle,
The membership function based on the weight of the vehicle is to obtain a fitness for the weight detected or estimated by the vehicle weight detecting means for detecting or estimating the weight of the vehicle,
The fuzzy rule uses a determination rule that selects a lower gear position as the detected or estimated weight increases based on the fitness of the weight.

An automatic transmission for a vehicle according to the present invention that solves the above problems is as follows.
In the automatic transmission of the vehicle,
The membership function based on the roadway gradient is to obtain a fitness for the gradient detected or estimated by the roadway gradient detection means for detecting or estimating the roadway gradient,
The fuzzy rule uses a determination rule that selects a lower gear position as the detected or estimated gradient increases based on the degree of fitness for the gradient.

An automatic transmission for a vehicle according to the present invention that solves the above problems is as follows.
In the automatic transmission of the vehicle,
The membership function based on the travel history of the vehicle is to obtain a fitness for the travel history of the vehicle speed detected by the vehicle speed detecting means for detecting the speed of the vehicle,
The fuzzy rule uses a determination rule that selects a lower gear position as the vehicle speed of the travel history increases based on the degree of fitness of the travel history with respect to the vehicle speed.
The vehicle travel history may be other, for example, as long as it reflects the driver's driving preferences and roadway conditions.

  According to the present invention, since the situation of the vehicle at the time of starting, that is, the starting stage corresponding to the starting load of the vehicle is selected based on the fuzzy rule, the startability is improved and the absorbed energy of the clutch is reduced, The life of the clutch can be extended.

  The automatic transmission for a vehicle according to the present invention has a start stage determining means for selecting an optimal shift stage at the time of starting, and the vehicle weight, roadway gradient, driver's travel history, etc. estimated in advance are selected as conditions. According to the fuzzy rule, the optimum starting gear is automatically selected.

  FIG. 1 is a schematic view showing an example of an embodiment of an automatic transmission for a vehicle according to the present invention.

  As shown in FIG. 1, an automatic transmission for a vehicle according to the present invention is mainly a torque connection / disconnection clutch mechanism (hereinafter referred to as a clutch) 1 having a dry single-plate friction clutch similar to a manual vehicle. Similarly, a synchronous mesh transmission (hereinafter referred to as transmission) 2 similar to a manual vehicle, and a gear shift unit (hereinafter referred to as GSU) 3 for performing a gear shift operation using a fluid pressure gear actuator (not shown). Etc. This is a so-called mechanical automatic transmission (hereinafter referred to as AMT), and is suitable for large vehicles such as trucks and buses, for example.

  In the engine 4, an injection pump 5 that supplies fuel to the engine 4 is controlled by a fuel injection amount signal L 1 between the injection pump 5 and the engine ECU 6, and an engine speed signal L 2 from the engine speed sensor 7 is output. It is configured to be monitored and maintained in a desired operating state.

  The clutch 1 is configured so that connection / disconnection control is automatically performed by a fluid pressure type clutch actuator 8. Specifically, the actual stroke signal L3 of the clutch actuator 8 is fed back to the AMT ECU 9, and a solenoid valve (not shown) in the fluid passage to the clutch actuator 8 is controlled by a control signal from the AMT ECU 9 based on the actual stroke. Thus, the actual stroke of the clutch actuator 8 is adjusted to the target stroke, and the clutch 1 is connected or disconnected by supplying or discharging the fluid to or from the clutch actuator 8. Further, the fine adjustment of the actual stroke of the clutch 1 at the time of starting or shifting is performed by duty control that opens and closes the solenoid valve in a short cycle. By adjusting the duty ratio, the clutch actuator 8 is adjusted. The operation speed can be adjusted and the actual stroke position can be finely adjusted. The clutch actuator 8 is provided with a clutch stroke sensor (not shown) for detecting the actual stroke of the clutch so that the actual stroke becomes the target stroke based on the actual stroke signal L3 detected by the clutch stroke sensor. PID feedback control is performed.

  The transmission 2 (transmission) is an automatic transmission that has a plurality of forward gears in addition to the reverse gear. A GSU 3 (gear stage selection means) for selecting a gear position inside the transmission is provided at the upper part of the transmission 2, and the GSU 3 is driven automatically by an internal gear actuator or the like driven by the supplied fluid. A shift operation has been performed. The GSU 3 is provided with a gear position sensor (not shown) for detecting a gear position, and a gear position signal L4 from the gear position sensor is input to the AMT ECU 9, and control is performed from the AMT ECU 9 to the GSU 3 at the time of shifting. The signal L4 is output to perform the shift operation.

  The air tank 10 is provided as a main air pressure source for operating the brake, and is configured to supply the operating air to the wheel cylinders 13 and 14 via the air masters 11 and 12 to perform the operation. . These are controlled by a brake valve (not shown), and are configured to be automatically braked by the operation of uphill road start assist brake magnet valves 15 and 16 when starting uphill road.

  The operating air from the air tank 10 is supplied not only to the brake system of the wheel cylinders 13 and 14 but also to the gear actuator and clutch actuator 8 of the GSU 3, and a desired operation state is realized by each operation. It is configured to be. Therefore, in these actuators, air pressure is used as the fluid pressure (also referred to as a pneumatic actuator). In this embodiment, as the air pressure source (fluid pressure source), the air tank 10 which is the air pressure source for brake operation is used. And is backed up by the emergency air tank 17. In place of the pneumatic actuator, an electro-hydraulic actuator or an actuator directly driven by an electric motor may be used.

  The AMT ECU 9 receives the depression amount signal L5 from the accelerator pedal 18 and the uphill starting start brake signal L6 from the push button 19, respectively, the engine speed signal L2 from the engine ECU 6, and the clutch rotation of the clutch 1. The clutch rotational speed signal L7 from the number sensor 26, the gear position signal L4 from GSU3, and the vehicle speed signal L8 from the vehicle speed sensor 21 (vehicle speed detection means) of the transmission 2 are input. Based on these input signals, an accelerator signal L9 is output from the AMT ECU 9 to the engine ECU 6, a clutch disengagement control signal L3 is output to the clutch 1, and a gear position control signal L4 is output to the GSU3. Then, the operation of the clutch actuator 8 is controlled to perform the clutch connecting / disconnecting operation and the gear selection operation. In addition, necessary control signals are also output to the braking system and other devices, for example, the selected gear position is displayed on the gear position display 22 by the gear position signal L10. .

  Furthermore, the automatic transmission of the vehicle according to the present invention includes a vehicle weight detection device 23 (vehicle weight detection means) for detecting the weight of the vehicle, and a roadway gradient detection device 24 (roadway gradient detection means) for detecting the gradient of the roadway. The vehicle weight signal L11 of the vehicle weight detection device 23, the roadway gradient signal L12 of the roadway gradient detection device 24, etc., which are provided and input to the AMT ECU 9, are used for fuzzy control vehicle weight estimation logic B1 and roadway gradient estimation logic B2 to be described later. Used as a condition for optimally selecting the gear position at the start. In addition, as a vehicle weight detection apparatus, the displacement amount at the time of the vehicle stop of the spring which supports a vehicle may be detected, for example, and a vehicle weight may be estimated. Further, as the roadway gradient detection device, for example, a G sensor may be provided, and the inclination of the vehicle, that is, the roadway gradient may be estimated by the G sensor.

  The driver's operation command is configured to be transmitted by the accelerator opening and the position of a shift lever (not shown), and will be described later when the shift lever is set to the D range after driving the engine. Based on the rule, when the gear is selected as either “1st” or “2nd” and the accelerator pedal 18 is depressed, the start operation is started.

  The starting operation is accompanied by the coupling operation of the clutch 1. The clutch control related to the coupling of the clutch 1 is performed in conjunction with the engine control corresponding to the accelerator opening so that the starting operation can be smoothly performed without a shock. Even during traveling, clutch control and shift control are performed in conjunction with engine control in accordance with the accelerator opening. For this reason, in these control systems, maps relating to gear selection data and clutch stroke data corresponding to the accelerator opening are stored. Using such maps, clutch control, shift control and engine Control is performed in conjunction with each other. Further, when starting on an uphill road, pressing the push button 19 activates an auxiliary brake for starting the hill, and is controlled to release the braking state of the brake at an appropriate timing in conjunction with the starting operation. ing.

  The engine ECU 6 and the AMT ECU 9 are each an arithmetic processing device (so-called CPU), a storage device (so-called ROM, RAM, and a storage area and arithmetic work area for holding control programs, map data, etc.), and input / output. It is composed of an interface or the like that becomes a signal processing circuit. An operation is performed using map data in the storage area based on an input signal (detection value or the like by a sensor), and the engine and the clutch device are controlled based on the calculated operation result.

  In the above-described automatic transmission according to the present invention, the AMT ECU 16 has the control means according to the present invention, and the optimum starting gear stage is selected by using the following starting stage determining means. An example of the control will be described with reference to FIGS. 2, 3, 5 and Tables 1 and 2. FIG.

  FIG. 2 is a flowchart of gear stage selection control at the time of start in the automatic transmission according to the present invention. FIG. 3 is a block diagram used for gear stage selection control at the time of start. Tables 1 (a) and (b) ) Is a membership function table used for gear stage selection control at the time of start, and FIGS. 5A and 5B are graphs of the membership function table of Tables 1A and 1B. 2 is a fuzzy rule table used for gear stage selection control at the time of start.

  As shown in the flowchart of FIG. 2, the gear position selection control at the time of start in the automatic transmission according to the present invention is as follows when the shift lever is in the D range when the vehicle is stopped. After that, the start gear position according to the vehicle condition is selected, and the vehicle starts to move.

(Step 1)
First, check if the vehicle speed is below the specified value. If it demonstrates with reference to FIG. 1, it will be confirmed whether the vehicle speed detected by the vehicle speed sensor 21 is specifically 2 km / h or less. In other words, this check is performed to determine whether or not the vehicle is stopped.

(Step 2)
If the vehicle speed is less than the specified value, check whether the current gear stage is the optimum target stage at the start. If the current gear stage and the target stage are the same, the control is terminated and the vehicle starts at that gear stage.

(Step 3)
If the current gear stage and the target stage are not the same, the gear stage is shifted to the target stage at AMT. Thereafter, the vehicle is started at the shifted gear.

  Here, as a method of determining the target stage in the above procedure, the method shown in FIG. 3, Table 1 (FIG. 5), and Table 2 is used.

  Specifically, a fuzzy rule is used as a method for determining the target stage of the starting gear. For this reason, first, in order to obtain the degree of conformity with respect to the gradient and weight as input conditions, a membership function that forms a trapezoidal or triangular graph is defined by the four-point parameter method (Tables 1 (a), 1 (b) and FIG. 1). 5 (a) and (b)).

  For example, in Table 1 (a), the gradient of the roadway is set from −20% to −10% as a certain degree of fitness, and from −10% to 0% so that the fitness decreases, ", That is, a region where the starting load is small. Also, the slope of the roadway is set from -5% to 0% so that the fitness level increases, and from 0% to 5% is set so that the fitness level decreases. The starting load is an intermediate area. Furthermore, the range of 0% to 10% is set so that the fitness level increases, and the road gradient is 10% to 20% with a certain level of fitness level. (See FIG. 5A).

  In Table 1 (b), the weight of the vehicle is set from 0 kg to 10000 kg so that the fitness is decreased, and the evaluation is “small”, that is, the area where the starting load is small. In addition, the vehicle weight is set to increase from 10000 kg to 15000 kg so that the fitness is increased, and the fitness is set to decrease from 15000 kg to 20000 kg so that the evaluation is “medium”, that is, the start load is intermediate. As an area. Furthermore, from 15000 kg to 20000 kg is set so that the fitness level increases, and the weight of the vehicle is set to a constant fitness level from 20000 kg to 30000 kg, and the evaluation is “large”, that is, the region where the starting load is large (see FIG. 5 (b)).

  Note that these membership functions are definitions as an example of the present invention, and can be changed as appropriate according to various conditions such as the type of vehicle and the maximum weight of the vehicle.

  Also, a rule that associates the fitness, evaluation, etc., output by the membership function with the selection of the gear stage is defined (see Table 2).

  The roadway gradient estimation logic unit B1 in FIG. 3 detects or estimates the roadway gradient using the roadway gradient detection device 24, and the vehicle weight estimation logic unit B2 uses the vehicle weight detection device 23 to determine the vehicle weight. Detected or estimated. Then, the determining unit B3 uses the detected or estimated gradient value and weight value, and for all the rules in Table 2 above, specifically, for the rules 1 to 9, members of the roadway gradient in Table 1 (a) above. With reference to the ship function and the membership function of the vehicle weight in Table 1 (b), the fitness of the gradient and the weight for each evaluation (large, medium, small) is obtained. Then, fuzzy calculation is performed on these fitness values and gear stage values with weighting (center of gravity method) to determine the optimum start gear stage, that is, the target stage at the start.

  In this embodiment, the configuration of the AMT shown in FIG. 1 and the control flow shown in FIG. Therefore, the description which overlaps is abbreviate | omitted and it demonstrates focusing on the characteristic part of a present Example.

  In the present embodiment, the difference from the first embodiment is that the starting gear stage determination method is different. Specifically, in addition to the gradient and weight, which are the membership functions of the first embodiment, the vehicle speed condition is a new membership function (see Table 3 (c)). Conditions were added (see Table 4).

  As a condition relating to the vehicle speed, the vehicle speed from the vehicle speed sensor 21 is accumulated as a travel history of the vehicle, and based on this, it is reflected in the selection of the gear position at the start. This is added in order to make the driver's driving preference and road conditions (low speed driving in traffic jams and high speed driving on highways) as one selection condition. Specifically, as shown in Table 3 (c), the membership function based on the running history of the vehicle is set so that the fitness is reduced from 0 to 50, and the evaluation “small” region, That is, it is set as the area | region where starting load is small. Also, the vehicle speed is set from 40 to 50 so as to increase the fitness level, and from 50 to 200 is set as a certain fitness level, which is an evaluation “high” region, that is, a region where the starting load is large (FIG. 5 ( c)). The travel history is not limited only to the vehicle speed. For example, the accelerator opening converted from the accelerator pedal depression amount is accumulated as the travel history, and the depression amount (accelerator opening) is large. You may define the membership function which selects a low gear stage, so that it is large.

  The roadway gradient estimation logic unit B1 in FIG. 4 detects or estimates the roadway gradient using the roadway gradient detection device 24, and the vehicle weight estimation logic unit B2 uses the vehicle weight detection device 23 to determine the vehicle weight. Detected or estimated, the travel history accumulation logic unit B4 uses the vehicle speed sensor 21 to accumulate past travel histories. Then, the determination unit B3 uses the detected or estimated gradient value, weight value, and accumulated vehicle speed, and for all the rules in Table 4 above, specifically, for the rules 1 to 18, the above Table 3 (a). Referring to the membership function of the roadway slope, the membership function of the vehicle weight in Table 3 (b) and the membership function of the vehicle speed in Table 3 (c), the slope for each evaluation (large, medium, and small) Find the fitness of weight and vehicle speed. Then, fuzzy calculation is performed on these fitness values and gear stage values with weighting (center of gravity method) to determine the optimum start gear stage, that is, the target stage at the start.

  In this embodiment, for example, when driving at a low speed such as in a traffic jam, an appropriate start gear stage can be selected and a smooth start can be performed without selecting a start gear stage that can be accelerated rapidly based on the accumulated travel history. In addition, when the vehicle travels at a high speed on a highway or the like, when the vehicle is temporarily stopped and started again, a start gear stage capable of rapid acceleration is selected, and the vehicle can start smoothly.

It is the schematic of the automatic transmission of the vehicle which concerns on this invention. 4 is a flowchart of start gear stage selection control performed by the vehicle automatic transmission according to the present invention. It is a block diagram used for gear stage selection control at the time of start concerning the present invention. It is a block diagram used for gear stage selection control at the time of start concerning the present invention. It is a graph of the membership function used for gear stage selection control at the time of start concerning the present invention.

Explanation of symbols

1 clutch 2 transmission 3 engine 5 engine ECU
6 Actuator 7 Air tank 15 Gear shift unit 16 ECU for AMT
17 Vehicle speed sensor 18 Accelerator pedal 20 Gear position indicator 21 Vehicle weight detection device 22 Roadway gradient detection device

Claims (5)

Gear stage selection means for selecting the gear stage of the transmission;
Control means for controlling the shift speed selection means,
The automatic transmission for a vehicle according to claim 1, wherein the control means includes start stage determining means for determining an optimum shift stage at the time of starting by determining a vehicle condition based on a fuzzy rule. The automatic transmission for a vehicle according to claim 1, wherein
The start stage determining means is a fuzzy rule for determining the vehicle status, and includes at least one of a membership function based on the weight of the vehicle, a membership function based on the gradient of the roadway, and a membership function based on the traveling history of the vehicle, or An automatic transmission for a vehicle characterized by using a plurality of combined conditions. The automatic transmission for a vehicle according to claim 2,
The membership function based on the weight of the vehicle is to obtain a fitness for the weight detected or estimated by the vehicle weight detecting means for detecting or estimating the weight of the vehicle,
The automatic transmission for a vehicle according to claim 1, wherein the fuzzy rule uses a determination rule that selects a lower gear position as the detected or estimated weight increases based on the fitness of the weight. In the automatic transmission for a vehicle according to claim 2 or claim 3,
The membership function based on the roadway gradient is to obtain a degree of fitness for the gradient detected or estimated by the roadway gradient detection means for detecting or estimating the roadway gradient,
The automatic transmission for a vehicle according to claim 1, wherein the fuzzy rule uses a determination rule that selects a lower gear position as the detected or estimated gradient becomes larger, based on the degree of fitness for the gradient. The automatic transmission for a vehicle according to any one of claims 2 to 4,
The membership function based on the travel history of the vehicle is to obtain a fitness for the travel history of the vehicle speed detected by the vehicle speed detecting means for detecting the speed of the vehicle,
The automatic transmission for a vehicle according to claim 1, wherein the fuzzy rule uses a determination rule that selects a lower gear position as the vehicle speed of the travel history increases based on a degree of fitness of the travel history with respect to a vehicle speed.

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