Automatic transmission system

Abstract

To provide an automatic transmission system capable of reducing a feeling of discomfort experienced by a driver during a gear shift in a vehicle mounted with an automated manual transmission.SOLUTION: An automatic transmission system 10 comprises: an automatic transmission 3 which has a clutch 11 and a gear stage 13, is connected to a drive source 1 generating propulsion force for a vehicle 100 through the clutch 11, and performs a gear shift by automatically controlling the clutch 11 and the gear stage 13; and a reaction force generating device 8 which applies reaction force to an accelerator pedal 21 in response to accelerator operation by a driver. The reaction force generating device 8 adjusts magnitude of the reaction force applied to the accelerator pedal 21 depending on a type of the gear shift.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an automatic transmission system. [Background technology]

[0002] A known accelerator pedal reaction force control system for a vehicle notifies the operator when the pedal is within a predetermined range or when it deviates from the predetermined range. The accelerator pedal reaction force control system for a vehicle includes a reaction force generating means for generating a reaction force on the accelerator pedal and a reaction force control means for setting the reaction force in relation to the amount of accelerator pedal operation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5560597 Summary of the Invention [Problem to be solved by the invention]

[0004] In a vehicle equipped with an automated manual transmission (AMT), a type of transmission, when the clutch is disengaged during gear shifting, a loss of driving force from the vehicle's drive source to the vehicle's drive wheels occurs, a phenomenon known as torque loss. As a result, even though the driver continues to depress the accelerator pedal during gear shifting, vehicle acceleration is suppressed. This creates a discrepancy between the actual vehicle speed and the vehicle speed perceived by the driver, which can cause discomfort to the driver.

[0005] The present invention has been made in consideration of the above-described circumstances, and aims to provide an automatic transmission system that can reduce the sense of discomfort felt by the driver when shifting gears in a vehicle equipped with an AMT. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, an automatic transmission system according to an embodiment of the present invention includes an automatic transmission having a clutch and a gear, connected via the clutch to a drive source that generates a propulsive force for a vehicle, and automatically controlling the clutch and the gear to perform gear changes, and a reaction force generating device that applies a reaction force to an accelerator pedal in response to an accelerator depression operation by a driver. The reaction force generating device changes the magnitude of the reaction force applied to the accelerator pedal depending on the type of gear change. [Effects of the Invention]

[0007] The present invention provides an automatic transmission system that can reduce the sense of discomfort felt by the driver when shifting gears in a vehicle equipped with an AMT. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing the configuration of a vehicle equipped with an automatic transmission system according to an embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a reaction force generating device of an automatic transmission system according to an embodiment of the present invention; [Figure 3] 3 is a timing chart showing the behavior of a vehicle equipped with an automatic transmission system according to an embodiment of the present invention during gear shifting in a time series manner. [Figure 4] 4 is a flowchart showing an example of a processing procedure for accelerator pedal reaction force control by the automatic transmission system according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] An embodiment of an automatic transmission system according to the present invention will be described with reference to FIGS. 1 to 4. FIG.

[0010] 1 is a schematic diagram showing the configuration of a vehicle equipped with an automatic transmission system according to an embodiment of the present invention. In the drawings, the same or corresponding components are designated by the same reference numerals.

[0011] As shown in FIG. 1, a vehicle 100 equipped with an automatic transmission system 10 according to this embodiment includes a drive source 1 that generates a propulsive force for the vehicle 100, an automatic transmission 3 that performs gear changes, an accelerator control device 5 that controls the drive source 1, a transmission control module (hereinafter referred to as "TCM") 7 that controls the automatic transmission 3, and a reaction force generator 8 that applies a reaction force in response to an accelerator depression operation by a driver. The drive source 1, the automatic transmission 3, the accelerator control device 5, the TCM 7, and the reaction force generator 8 are communicably connected to one another via an in-vehicle network 9. The in-vehicle network 9 is a bus-type network that uses, for example, a Controller Area Network (CAN) as a communication protocol. The automatic transmission system 10 according to this embodiment includes at least the automatic transmission 3 and the reaction force generator 8. The automatic transmission system 10 may also include the TCM 7.

[0012] Vehicle 100 may be an engine vehicle, an electric vehicle, a hybrid vehicle, or a fuel cell vehicle. The configuration of vehicle 100 and automatic transmission system 10 shown in Fig. 1 is an example, and vehicle 100 and automatic transmission system 10 may also be provided with other configurations.

[0013] The driving source 1 includes at least one of an internal combustion engine and an electric motor. If the driving source 1 includes both an engine and an electric motor, the vehicle 100 is a hybrid vehicle. If the driving source 1 includes an electric motor, the vehicle 100 is equipped with a battery for supplying power to the electric motor.

[0014] The automatic transmission 3 changes the speed of the rotation output from the drive source 1. A drive shaft (not shown) with drive wheels (not shown) attached to both ends is connected to the output shaft of the automatic transmission 3, for example, via a differential gear (not shown), and the speed-changed rotation is transmitted to the drive wheels to drive them. Furthermore, when the drive source 1 includes both an engine and an electric motor, the automatic transmission 3 changes the speed of at least the rotation output from the engine. In other words, the electric motor may be provided so that the rotation output from the electric motor is transmitted to, for example, a differential gear or a drive shaft without being changed in speed by the automatic transmission 3. In this case, the electric motor can generate propulsive force for the vehicle 100 without depending on the state of the clutch 11, which will be described later.

[0015] The automatic transmission 3 includes, for example, a clutch 11 that connects or disconnects power transmission from the drive source 1, multiple gear stages 13 with different gear ratios, an actuator 15 that hydraulically controls the clutch 11 and the multiple gear stages 13, and a hydraulic circuit 17 that serves as a hydraulic source for the actuator 15. The automatic transmission 3 is connected to the drive source 1 via the clutch 11, and performs gear changes by automatically controlling the clutch 11 and the gear stages 13. The automatic transmission 3 is, for example, a single-clutch AMT. The number of gear stages 13 is not particularly limited.

[0016] The clutch 11 is provided between the driving source 1 and the multiple gear stages 13, and connects or disconnects the power transmission from the driving source 1. The clutch 11 is, for example, a dry single-plate clutch. Hereinafter, the state in which the clutch 11 connects the power transmission from the driving source 1 may be referred to as the "ON state," and the state in which the clutch 11 disconnects the power transmission from the driving source 1 may be referred to as the "OFF state." Note that the intermediate state of the clutch 11 when it transitions from the OFF state to the ON state is what is called a half-clutch state.

[0017] The actuator 15 switches the clutch 11 between the ON state and the OFF state and switches among the multiple gear stages 13 in response to a gear change request signal from the TCM 7. The actuator 15 is, for example, a hydraulic actuator. The actuator 15 includes a clutch actuator (not shown) that controls the clutch 11 and a gear shift actuator (not shown) that controls the multiple gear stages 13.

[0018] The hydraulic circuit 17 includes, for example, an electric motor, a pump, and an oil tank that stores oil (not shown). The hydraulic circuit 17 receives oil from the oil tank and generates hydraulic pressure using the electric motor and the pump. The generated hydraulic pressure is used as a hydraulic pressure source for the actuator 15.

[0019] The accelerator control device 5 includes an accelerator pedal 21, an accelerator position sensor 23 attached to the accelerator pedal 21 and detecting the accelerator position as the amount of depression (operation amount) of the accelerator pedal 21 when the driver presses the accelerator, and a drive source control unit 25 that controls the drive source 1 based on the detection signal from the accelerator position sensor 23. The accelerator control device 5 also outputs the detection signal from the accelerator position sensor 23 to the TCM 7 and the reaction force generating device 8. Note that an accelerator press is an operation that means that the driving force (acceleration request) requested of the vehicle is at least not zero. Specifically, an accelerator press means, for example, that the operation amount of the accelerator pedal 21 is greater than zero or greater than the boundary value of a dead band.

[0020] The TCM 7 outputs a gear shift request signal to the automatic transmission 3 to perform gear shifting based on detection signals from the accelerator opening sensor 23 and various sensors (not shown) that are provided in the vehicle 100, thereby achieving optimal gear shift control in the automatic transmission 3. The various sensors include, for example, a vehicle speed sensor that detects the vehicle speed of the vehicle 100, a rotation sensor that detects the rotation output from the drive source 1, and a hydraulic sensor provided in the hydraulic circuit 17. The TCM 7 also outputs the gear shift request signal to the reaction force generating device 8.

[0021] FIG. 2 is a schematic diagram showing a reaction force generating device for an automatic transmission system according to an embodiment of the present invention.

[0022] As shown in FIG. 2 in addition to FIG. 1, the reaction force generating device 8 includes a reaction force transmission unit 31 that applies a reaction force to the accelerator pedal 21 in response to the driver's accelerator operation, and a reaction force control unit 33 that controls the reaction force transmission unit 31.

[0023] The reaction force transmission unit 31 includes, for example, at least one of a rotary actuator 31a and a linear actuator 31b. The rotary actuator 31a and the linear actuator 31b may be, for example, hydraulic actuators or electric actuators. In FIG. 2 , the force generated when the driver depresses the pedal 21a of the accelerator pedal 21 by operating the accelerator pedal is defined as a depression force F1. In this case, the rotary actuator 31a is provided, for example, on the pedal shaft 21b of the accelerator pedal 21 and generates a torque N whose positive direction is clockwise around the pedal shaft 21b. At this time, the rotary actuator 31a generates a reaction force in the pedal 21a in response to the depression force F1, which is calculated by dividing the torque N by the distance L from the pedal 21a to the pedal shaft 21b. Furthermore, the linear actuator 31b generates, for example, a reaction force F2 in the pedal arm 21c of the accelerator pedal 21 from the direction opposite to the depression force F1. It should be noted that the reaction force applied by the reaction force transmission unit 31 to the accelerator pedal 21 does not include the reaction force from an elastic member (biasing member) such as a spring that is provided on the accelerator pedal 21 and returns the accelerator pedal 21 to its initial position (rest position) when the driver presses the accelerator pedal 21.

[0024] The reaction force control unit 33 controls the reaction force transmission unit 31 based on, for example, a detection signal from the accelerator opening sensor 23 from the accelerator control device 5 and a gear change request signal from the TCM 7, to apply a reaction force to the accelerator pedal 21.

[0025] Furthermore, the drive source control unit 25 and TCM 7 of the accelerator control device 5, and the reaction force control unit 33 of the reaction force generating unit 8 can each be configured as a computer equipped with a processor such as a CPU, and a storage device such as a read-only memory (ROM), a random access memory (RAM), and an HDD (hard disk drive). In this case, for example, the functions of the drive source control unit 25, TCM 7, and reaction force control unit 33 can be realized by the processor executing a predetermined program stored in the storage device. Furthermore, instead of such software processing, these functions can also be realized by hardware such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA).

[0026] As mentioned above, in a vehicle equipped with an AMT, if the driver continues to depress the accelerator pedal during a gear shift and the clutch is disengaged, the driving force from the vehicle's drive source is not transmitted to the vehicle's drive wheels, causing the vehicle's acceleration to stagnate or decelerate, a phenomenon known as "torque loss." If torque loss occurs while the accelerator pedal is continuously depressed, a difference will arise between the actual vehicle speed and the vehicle speed perceived by the driver, which may cause the driver to feel uncomfortable. Furthermore, whether or not this feeling of discomfort occurs depends on the type of gear shift.

[0027] Therefore, the reaction force generating device 8 of the automatic transmission system 10 of this embodiment changes the magnitude of the reaction force applied to the accelerator pedal 21 when the automatic transmission 3 is shifting gears, depending on the type of gear shift.

[0028] Typically, when shifting gears in a vehicle equipped with a manual transmission (MT), the driver releases the accelerator pedal, so torque loss does not occur at a timing the driver does not expect. In other words, even if torque loss occurs during a shift in a vehicle equipped with a manual transmission, the driver knows when the shift is occurring, so the driver does not feel uncomfortable. On the other hand, in a vehicle equipped with an automatic transmission (AMT), the shift is performed while the driver continues to depress the accelerator pedal, so torque loss tends to occur at a timing the driver does not expect, which tends to cause the driver to feel uncomfortable. It has been revealed that this tendency occurs when the driver accelerates the vehicle with an accelerator pedal depression angle greater than a certain level. Therefore, reaction force generating device 8 generates a reaction force when the shift is occurring in a situation that would cause the driver to feel uncomfortable, and does not generate a reaction force when the shift is occurring in a situation that would not cause the driver to feel uncomfortable. This distinguishes between situations in which a reaction force is generated on accelerator pedal 21 and situations in which a reaction force is not generated. This enables a shift to be performed without causing the driver to feel uncomfortable. In other words, in situations where the driver feels uncomfortable when changing gears, reaction force generating device 8 generates a reaction force that pushes back, or releases, the driver's depression of accelerator pedal 21, thereby making the driver realize that he or she cannot further depress accelerator pedal 21 and that acceleration will not occur. Furthermore, reaction force generating device 8 uses the generated reaction force to notify the driver of the timing of the gear change, thereby reducing the discomfort the driver feels when changing gears. The reaction force that reaction force generating device 8 applies to accelerator pedal 21 may be referred to as "accelerator pedal reaction force" below. Furthermore, control by reaction force generating device 8 to apply to accelerator pedal 21 a reaction force that is large enough to be felt by the driver and large enough to limit the driver's accelerator operation may be referred to as "accelerator pedal reaction force control" below.

[0029] The types of gear changes that change the magnitude of the reaction force that reaction force generating device 8 applies to accelerator pedal 21 will be described in detail below.

[0030] Reaction force generating device 8 may apply a reaction force to accelerator pedal 21 when the gear change is accompanied by the driver's intention to accelerate, and may apply a smaller reaction force to accelerator pedal 21 when the gear change is not accompanied by the driver's intention to accelerate than when the gear change is accompanied by the driver's intention to accelerate. In other words, reaction force generating device 8 may distinguish between a gear change when the driver intends to accelerate and a gear change when the driver does not intend to accelerate, and may apply a smaller reaction force to accelerator pedal 21 when the gear change is accompanied by the driver's intention to accelerate than when the driver intends to accelerate.

[0031] In a vehicle equipped with an AMT, a driver may feel uncomfortable when a gear shift occurs unexpectedly while the driver continues to depress the accelerator pedal with the intention of accelerating. Therefore, when a gear shift occurs while the driver intends to accelerate, the driver feels a relatively large reaction force applied to accelerator pedal 21, which allows the driver to recognize that a gear shift is occurring. In other words, the driver can grasp the timing of a gear shift while intending to accelerate. On the other hand, when a gear shift occurs without the driver intending to accelerate, the driver does not feel uncomfortable. In other words, the driver does not need to recognize that a gear shift is occurring, so a small reaction force can be applied to accelerator pedal 21. Therefore, reaction force generating device 8 reduces the discomfort felt by the driver when a gear shift occurs while the driver is depressing accelerator pedal 21. Furthermore, reaction force generating device 8 applies a reaction force to accelerator pedal 21 only during a gear shift, even if the driver intends to accelerate. Therefore, the reaction force does not interfere with acceleration caused by the driver's accelerator operation at times other than when a gear shift is occurring.

[0032] Note that the reaction force applied to accelerator pedal 21 when the gear change is accompanied by the driver's intention to accelerate may include, for example, a reaction force large enough to prevent the driver from further depressing accelerator pedal 21. On the other hand, the reaction force applied to accelerator pedal 21 when the gear change is not accompanied by the driver's intention to accelerate may include, for example, a reaction force of zero, which does not generate any reaction force.

[0033] FIG. 3 is a timing chart showing the behavior of a vehicle equipped with an automatic transmission system according to an embodiment of the present invention during gear shifting in a time series manner.

[0034] Here, the difference in accelerator pedal reaction force generated by reaction force generating device 8 between a gear change when the driver intends to accelerate and a gear change when the driver does not intend to accelerate will be explained with reference to Figure 3. Note that the accelerator opening, clutch state, transmission torque, and accelerator pedal reaction force changes over time shown in Figure 3 are merely examples to facilitate understanding of the following explanation.

[0035] As shown in Figure 3, when the driver continues to depress accelerator pedal 21 with the intention of accelerating, the accelerator opening continues to increase, and at time t1, clutch 11 changes from the ON state to the OFF state. When clutch 11 changes to the OFF state, the transmission torque suddenly decreases to zero. In other words, a torque drop occurs. At time t1, reaction force generator 8 generates accelerator pedal reaction force, indicated by solid line P, to notify the driver of the timing of the gear shift, thereby reducing the discomfort felt by the driver due to the gear shift. Note that at time t2, the transmission torque begins to increase from zero. This is torque generated by the electric motor, which is installed in drive source 1 including an engine and an electric motor and is configured to transmit output rotation to a differential gear or a drive shaft, regardless of the state of clutch 11.

[0036] Next, at time t3, clutch 11 transitions from the OFF state to the ON state, entering a so-called half-clutch state. Then, at time t4, clutch 11 enters the ON state, completing the shift, and reaction force generator 8 stops generating accelerator pedal reaction force. In other words, reaction force generator 8 generates accelerator pedal reaction force only from time t1 to t4 when the shift is being performed. On the other hand, when the shift is not accompanied by the driver's intention to accelerate, reaction force generator 8 generates an accelerator pedal reaction force indicated by dashed dotted line Q during the shift from time t1 to t4 when the shift is being performed, which is smaller than when the driver's intention to accelerate.

[0037] In Figure 3, the change in accelerator pedal reaction force over time when the driver intends to accelerate, as indicated by the solid line P, is zero before time t1 and after time t4. However, for example, a constant reaction force greater than zero may be generated as an offset value. In this case, the reaction force applied to accelerator pedal 21 from time t1 to time t4 increases by the amount of this offset value. In other words, the reaction force originally applied to accelerator pedal 21 may be further increased while the gear is being changed.

[0038] Furthermore, the reaction force generator 8 may determine the driver's intention to accelerate during gear changes from the accelerator opening and accelerator opening speed. That is, the reaction force generator 8 may determine that the driver intends to accelerate when the accelerator opening is equal to or greater than a first accelerator opening, which is a predetermined threshold, and the accelerator opening speed is equal to or greater than a first accelerator opening speed, which is a predetermined threshold. Alternatively, the reaction force generator 8 may determine that the driver does not intend to accelerate when the accelerator opening is less than the first accelerator opening and / or the accelerator opening speed is less than the first accelerator opening speed. The accelerator opening speed is the rate of change in the accelerator opening, which indicates the change in the accelerator opening per second. The reaction force generator 8 can obtain the accelerator opening speed by differentiating, with respect to time, the detection signal of the accelerator opening sensor 23, which indicates the accelerator opening and is output from the accelerator control device 5.

[0039] As described above, in a vehicle equipped with an AMT, gear changes are performed while the driver continues to depress the accelerator pedal with the intention to accelerate, which tends to cause torque loss at times unexpected by the driver, causing discomfort to the driver. This tendency occurs when the vehicle is accelerated with an accelerator pedal depression greater than a certain level. Therefore, the driver's intention to accelerate is correlated with the accelerator pedal depression and further with the accelerator opening speed. The system determines that the driver intends to accelerate when the accelerator pedal depression and accelerator opening speed exceed their respective predetermined thresholds. This prevents the reaction force generating device 8 from applying a large, annoying reaction force to the accelerator pedal 21 during gear changes, improving the driver's comfort during gear changes. For example, when the driver wants to accelerate the vehicle 100 slowly, or when the driver depresses the accelerator pedal 21 with the intention of maintaining a constant vehicle speed but is actually accelerating the vehicle 100 slowly, the reaction force generating device 8 prevents the driver from experiencing a gear change. This improves the driver's comfort during gear changes.

[0040] Furthermore, reaction force generating device 8 may determine that the driver has a strong intention to accelerate when the accelerator opening exceeds a second accelerator opening that is greater than the first accelerator opening and the accelerator opening speed exceeds a second accelerator opening speed that is greater than the first accelerator opening speed, or when the accelerator opening is in the full throttle range regardless of the magnitude of the accelerator opening speed, and may apply a smaller reaction force to accelerator pedal 21 than when the driver does not have a strong intention to accelerate. In this way, reaction force generating device 8 may improve the comfort felt by the driver by weakening or not applying any reaction force that would hinder the driver's accelerator operation when changing gears, for example, when the accelerator opening that indicates a strong intention to accelerate is full throttle acceleration, which is acceleration in the full throttle range.

[0041] The full accelerator opening range is the designed full accelerator opening range, and refers to the accelerator opening range from just before accelerator pedal 21 can no longer be depressed until it can no longer be depressed. The second accelerator opening range is not included in the full accelerator opening range and is smaller than the full accelerator opening range. Furthermore, when it is determined that the driver has a strong intention to accelerate, the reaction force applied to accelerator pedal 21 may include, for example, a reaction force that is zero, which means that no reaction force is generated.

[0042] Furthermore, when the shift is accompanied by the driver's intention to accelerate and is a kick-down shift, the reaction force generating device 8 may apply a smaller reaction force to the accelerator pedal 21 than when the shift is accompanied by the driver's intention to accelerate and is not a kick-down shift.

[0043] In a kickdown gear shift, the driver strongly depresses accelerator pedal 21. Therefore, reaction force generating device 8 reduces the reaction force applied to accelerator pedal 21 during a kickdown gear shift, even when the driver intends to accelerate, so as not to interfere with the strong depression of accelerator pedal 21 that accompanies a kickdown gear shift. In this way, reaction force generating device 8 does not interfere with the driver's accelerator operation with a reaction force, improving the comfort felt by the driver when changing gears.

[0044] A kickdown shift is a shift in which the gear is downshifted to improve acceleration performance. Since a kickdown shift occurs when the driver strongly depresses the accelerator pedal, the driver can grasp the timing of the shift, i.e., the timing when torque loss occurs. Therefore, a kickdown shift does not usually cause discomfort to the driver.

[0045] A gear shift not accompanied by the driver's intention to accelerate may include an off-up gear shift. An off-up gear shift is a gear shift in which the driver stops depressing the accelerator pedal and releases it (releases the accelerator pedal) while the vehicle is accelerating. For example, while the accelerator pedal 21 is depressed to cause the accelerator position signal of the accelerator position sensor 23 to be in an ON state (e.g., the accelerator position is equal to or greater than a predetermined value) and the gear 13 is traveling in first gear, the accelerator pedal 21 is released to cause the accelerator position signal of the accelerator position sensor 23 to be in an OFF state (e.g., the accelerator position is less than a predetermined value), thereby shifting the gear 13 up to second gear. This off-up gear shift is not accompanied by the driver's intention to accelerate. Therefore, in an off-up gear shift, the reaction force generating device 8 does not need to make the driver aware that a gear shift is occurring, and by reducing the reaction force, the driver does not feel any discomfort and improves the comfort felt by the driver.

[0046] The reaction force that the reaction force generator 8 applies to the accelerator pedal 21 may utilize the hydraulic pressure used when the automatic transmission 3 shifts gears. That is, as shown again in FIG. 2 , the reaction force generator 8 may further include, for example, a hydraulic pressure adjustment unit 35 that adjusts the hydraulic pressure, and the reaction force control unit 33 may control the hydraulic pressure adjustment unit 35 to adjust the hydraulic pressure generated in the hydraulic circuit 17 of the automatic transmission 3, thereby driving the reaction force transmission unit 31. In this case, the reaction force transmission unit 31 is a hydraulic actuator. In this way, the reaction force generator 8 applies a reaction force to the accelerator pedal 21 using the hydraulic pressure used to control the clutch 11 and the gear 13 when the automatic transmission 3 shifts gears. That is, the reaction force generator 8 does not require a separate hydraulic pressure source to drive the reaction force transmission unit 31. The hydraulic pressure adjustment unit 35 may be incorporated into the reaction force transmission unit 31, which is a hydraulic actuator, and may be integrated into the reaction force transmission unit 31.

[0047] FIG. 4 is a flowchart showing an example of a processing procedure for accelerator pedal reaction force control by the automatic transmission system according to the embodiment of the present invention.

[0048] Now, with reference to Figure 4, the operation (accelerator pedal reaction force control) of the automatic transmission system 10 according to this embodiment will be described. The flowchart in Figure 4 is made up of steps S1 to S7. For ease of explanation, it is assumed that the vehicle 100 equipped with the automatic transmission system 10 is traveling. In addition, in the figure, the first accelerator opening is represented as "APO1," the second accelerator opening as "APO2," the first accelerator opening speed as "APOS1," and the second accelerator opening speed as "APOS2."

[0049] 4, first, in step S1, the automatic transmission system 10 determines whether or not there is a gear change request (gear change request signal) from the TCM 7. If there is a gear change request from the TCM 7 (YES in step S1), the process proceeds to step S2, and if there is no gear change request from the TCM 7 (NO in step S1), the process proceeds to END, where the current control is terminated. In other words, if there is no gear change request from the TCM 7, the accelerator pedal reaction force control is not executed.

[0050] In step S2 following YES in step S1, the automatic transmission system 10 determines whether the gearshift request from the TCM 7 is an upshift. If the gearshift request signal is an upshift (YES in step S2), the process proceeds to step S3, and if the gearshift request is not an upshift (NO in step S2), the process proceeds to END, where the current control is terminated. In other words, if the gearshift is not an upshift, the accelerator pedal reaction force control is not executed.

[0051] In step S3 following YES in step S2, the automatic transmission system 10 determines whether the accelerator opening APO satisfies the following condition, that is, the following relational expression (1). APO1≦APO≦APO2 (1)

[0052] If the accelerator opening APO satisfies the above relational expression (1) (YES in step S3), the process proceeds to step S4, but if the accelerator opening APO does not satisfy the above relational expression (1) (NO in step S3), the process proceeds to END, where the current control ends. In other words, if the accelerator opening APO, which is the amount of depression of the accelerator pedal 21 by the driver, is outside the range from the first accelerator opening APO1 to the second accelerator opening APO2, accelerator pedal reaction force control is not executed.

[0053] In step S4 following the YES determination in step S3, the automatic transmission system 10 determines whether the accelerator opening speed APOS satisfies the following condition, that is, the following relational expression (2). APOS1≦APOS≦APOS2 (2)

[0054] If the accelerator opening speed APOS satisfies the above relational expression (2) (YES in step S4), the process proceeds to step S5, but if the accelerator opening speed APOS does not satisfy the above relational expression (2) (NO in step S4), the process proceeds to END, where the current control is terminated. In other words, if the accelerator opening speed APOS is outside the range from the first accelerator opening speed APOS1 to the second accelerator opening speed APOS2, the accelerator pedal reaction force control is not executed.

[0055] In step S5 following the YES determination in step S4, the automatic transmission system 10 performs accelerator pedal reaction force control. That is, the automatic transmission system 10 generates a reaction force in the accelerator pedal 21 in response to the driver's depression of the accelerator pedal 21, thereby making the driver aware that a gear shift is occurring and reducing the sense of discomfort felt by the driver during the gear shift.

[0056] In step S6 following step S5, the automatic transmission system 10 determines whether the gear shift is complete. If the gear shift is complete (YES in step S6), the process proceeds to step S7. If the gear shift is not complete (NO in step S6), the process of step S5 is repeatedly executed until the gear shift is complete.

[0057] In step S7 following the YES determination in step S6, the automatic transmission system 10 stops the accelerator pedal reaction force control. That is, the automatic transmission system 10 stops the generation of reaction force to the accelerator pedal 21.

[0058] After executing the process of step S7, the automatic transmission system 10 ends the current control.

[0059] As described above, the automatic transmission system 10 according to this embodiment includes a reaction force generator 8 that varies the magnitude of the reaction force applied to the accelerator pedal 21 depending on the type of gear shift. The reaction force generator 8 generates a reaction force when the gear shift is one that would cause discomfort to the driver, and does not generate a reaction force when the gear shift is one that would not cause discomfort to the driver, thereby distinguishing between situations in which a reaction force is applied to the accelerator pedal 21 and situations in which a reaction force is not applied. When the gear shift is one that would cause discomfort to the driver, the reaction force generator 8 generates a reaction force to the accelerator pedal 21 through accelerator pedal reaction force control, thereby informing the driver that acceleration will not be permitted and informing the driver of the timing of the gear shift, thereby reducing the discomfort felt by the driver during the gear shift. Therefore, the automatic transmission system 10 can perform gear shifts that do not cause discomfort to the driver. Furthermore, the automatic transmission system 10 generates a reaction force to the accelerator pedal 21 through accelerator pedal reaction force control during gear shifts, preventing the accelerator pedal 21 from being depressed excessively, thereby suppressing sudden re-acceleration after the gear shift.

[0060] Furthermore, automatic transmission system 10 according to this embodiment is equipped with reaction force generator 8 that applies a reaction force to accelerator pedal 21 when the gear shift is accompanied by the driver's intention to accelerate, and that applies a smaller reaction force to accelerator pedal 21 when the gear shift is not accompanied by the driver's intention to accelerate than when the gear shift is accompanied by the driver's intention to accelerate. Therefore, when the gear shift is accompanied by the driver's intention to accelerate, which would cause the driver to feel uncomfortable, automatic transmission system 10 applies a relatively large reaction force to accelerator pedal 21 through accelerator pedal reaction force control, thereby informing the driver of the timing of the gear shift and reducing the sense of discomfort felt by the driver.

[0061] Furthermore, automatic transmission system 10 according to this embodiment is equipped with reaction force generating device 8 that determines that the driver intends to accelerate when the accelerator opening is equal to or greater than a first accelerator opening, which is a predetermined threshold, and the accelerator opening speed is equal to or greater than a first accelerator opening speed, which is a predetermined threshold, and determines that the driver does not intend to accelerate when the accelerator opening is less than the first accelerator opening and / or the accelerator opening speed is less than the first accelerator opening speed. Therefore, automatic transmission system 10 does not apply a large reaction force to accelerator pedal 21 due to accelerator pedal reaction force control, which would be annoying to the driver, when, for example, the driver wants to accelerate vehicle 100 slowly or when the driver is accelerating slowly and unintentionally, the automatic transmission system can improve the comfort felt by the driver when changing gears.

[0062] Furthermore, the automatic transmission system 10 according to this embodiment is equipped with a reaction force generator 8 that determines that the driver has a strong intention to accelerate when the accelerator opening exceeds a second accelerator opening that is greater than the first accelerator opening and the accelerator opening speed exceeds a second accelerator opening speed that is greater than the first accelerator opening speed, or when the accelerator opening is in the fully open range, and applies a smaller reaction force to the accelerator pedal 21 than when the driver's intention to accelerate is not strong. Therefore, when the driver is accelerating at full throttle during a gear change, for example, the automatic transmission system 10 can improve the comfort felt by the driver without compromising it by weakening or not applying any reaction force that would hinder the driver's accelerator operation.

[0063] Furthermore, automatic transmission system 10 according to this embodiment is equipped with reaction force generator 8 that reduces the reaction force applied to accelerator pedal 21 when the shift is accompanied by the driver's intention to accelerate and is a kickdown shift, compared to when the shift is accompanied by the driver's intention to accelerate and is not a kickdown shift. Therefore, automatic transmission system 10 does not prevent the driver from strongly depressing accelerator pedal 21 in conjunction with a kickdown shift, thereby improving the comfort felt by the driver during gear changes without compromising it.

[0064] Furthermore, in the automatic transmission system 10 according to this embodiment, gear changes that are not accompanied by the driver's intention to accelerate include off-up gear changes. Therefore, in the off-up gear changes, the automatic transmission system 10 does not need to make the driver aware that a gear change is occurring, and by reducing the reaction force applied to the accelerator pedal 21, it is possible to prevent the driver from feeling uncomfortable and improve the comfort felt by the driver.

[0065] Furthermore, the reaction force that the reaction force generating device 8 of the automatic transmission system 10 according to this embodiment applies to the accelerator pedal 21 utilizes the hydraulic pressure that is used when the automatic transmission 3 performs gear changes. Therefore, the automatic transmission system 10 can apply the reaction force to the accelerator pedal 21 using the hydraulic pressure generated in the hydraulic circuit 17 of the automatic transmission 3 without requiring a new hydraulic pressure source.

[0066] Therefore, the automatic transmission system 10 according to this embodiment can reduce the sense of discomfort felt by the driver when shifting gears in a vehicle 100 equipped with an AMT.

[0067] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0068] 1...Drive source, 3...Automatic transmission, 5...Accelerator control device, 7...Transmission control module (TCM), 8...Reaction force generating device, 9...In-vehicle network, 10...Automatic transmission system, 11...Clutch, 13...Gear stage, 15...Actuator, 17...Hydraulic circuit, 21...Accelerator pedal, 21a...Pedal, 21b...Pedal shaft, 21c...Pedal arm, 23...Accelerator opening sensor, 25...Drive source control unit, 31...Reaction force transmission unit, 31a...Rotary actuator, 31b...Linear actuator, 33...Reaction force control unit, 35...Hydraulic adjustment unit, 100...Vehicle

Claims

1. an automatic transmission having a clutch and a gear stage, connected via the clutch to a drive source that generates a propulsive force for the vehicle, and that automatically controls the clutch and the gear stage to change gears; a reaction force generating device that applies a reaction force to the accelerator pedal in response to an accelerator operation by a driver, The reaction force generating device changes the magnitude of the reaction force applied to the accelerator pedal depending on the type of gear shift.

2. The reaction force generating device is When the gear shift is accompanied by the driver's intention to accelerate, the reaction force is applied to the accelerator pedal; 2. The automatic transmission system according to claim 1, wherein when the gear shift is not accompanied by the intention to accelerate, the reaction force applied to the accelerator pedal is made smaller than when the gear shift is accompanied by the intention to accelerate.

3. The reaction force generating device is When the accelerator opening degree is equal to or greater than a first accelerator opening degree and the accelerator opening speed is equal to or greater than the first accelerator opening speed, it is determined that the driver has an intention to accelerate.

3. The automatic transmission system according to claim 2, wherein it is determined that there is no intention to accelerate when at least one of the accelerator opening degree is less than the first accelerator opening degree and the accelerator opening speed is less than the first accelerator opening speed.

4. 4. The automatic transmission system according to claim 3, wherein the reaction force generating device determines that the intention to accelerate is strong when the accelerator opening degree exceeds a second accelerator opening degree that is greater than the first accelerator opening degree and the accelerator opening speed exceeds a second accelerator opening speed that is greater than the first accelerator opening speed, or when the accelerator opening degree is in a fully opened range, and applies a smaller reaction force to the accelerator pedal than when the intention to accelerate is not strong.

5. 3. The automatic transmission system according to claim 2, wherein the reaction force generating device applies a smaller reaction force to the accelerator pedal when the gear shift is accompanied by the intent to accelerate and is a kick-down gear shift than when the gear shift is accompanied by the intent to accelerate and is not a kick-down gear shift.

6. 3. The automatic transmission system according to claim 2, wherein the gear change without an intention to accelerate includes an off-up gear change.

7. 2. The automatic transmission system according to claim 1, wherein the reaction force applied to the accelerator pedal by the reaction force generating device utilizes hydraulic pressure used by the automatic transmission when performing the gear shift.

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