vehicle with power transmission

Abstract

Method for improving the driving behavior of a motor vehicle (100; 110) during a gear shift operation, wherein there is a neutral stage of a transmission (240) of a power transmission of the vehicle, comprising the step - determining when a state of a clutch (235) of the vehicle (100; 110) changes from a first state to a second state, characterized by the steps - taking over control of an engine (230) of the vehicle (100; 110), optionally from a driver, on the basis of the determination, in order to automatically control the gearshift process in such a way that any desired gear position of the transmission is engaged, and - thereafter returning control of the engine (230) of the vehicle (100; 110) to a driver.

Description

Technical area

[0001] The present invention relates to a method for improving the drivability of a motor vehicle with a power transmission. The invention also relates to a computer program product comprising program code for a computer for implementing a method according to the invention. The invention also relates to a device and a motor vehicle equipped with the device. background

[0002] Today, there are vehicles in which a conventional mechanical gearshift lever has been replaced by a so-called electronic gearshift lever. An electronic gearshift lever is particularly advantageous in vehicles in which the vehicle's transmission is located at the rear of the vehicle. The electronic gearshift lever is a gearshift lever designed to communicate with a control unit of the vehicle. The control unit is designed to use control signals to control gearshifts of a vehicle's powertrain by means of various operating devices, such as solenoid valves. Such a system is referred to, for example, as an electro-pneumatic system. The vehicle manufacturer Scania uses a system called "shift-by-wire" in certain vehicles.

[0003] A disadvantage of such an electro-pneumatic system is the need to feed information back to the driver so that they can be aware that a new gear has been engaged. To this end, the driver can receive an indication or confirmation that the new gear has been engaged and that a clutch pedal can be released to achieve a closed-loop vehicle drivetrain. A gearshift lever suitable for such an electro-pneumatic system is therefore relatively expensive, as such systems can have a built-in feedback system. A gearshift lever suitable for such an electro-pneumatic system is therefore also relatively complicated. In contrast, in a conventional system with an entirely mechanical gearshift lever, the driver can detect when a new gear has been engaged through the gearshift lever, whereupon they can release the clutch pedal.However, as previously stated, these conventional systems are not suitable for all vehicle types. Such conventional systems are also not as user-friendly as an electro-pneumatic system.

[0004] Another currently known practice is to have an electronic control system of the vehicle assume control of a vehicle's engine when a gear of the vehicle's transmission is engaged in a neutral position during a gearshift, in order to subsequently coordinate a gearshift sequence with the vehicle's engine. This allows the driver to be permitted to release the clutch pedal during the gearshift and results in no need to provide the driver with confirmation that they have permission to release the clutch pedal. A disadvantage of this method is that the driver may feel that they are not in full control of the process and cannot balance the clutch and power requirements themselves after the gearshift has been performed.

[0005] WO 2008 / 026993 describes a method for gear shifting in a gear-by-wire system in a vehicle, which comprises a clutch, a gearbox and means for controlling the clutch to manually control the engagement and release of the latter, as well as gear selection means allowing manual indication of a desired gear.

[0006] However, there is a need to provide a method and apparatus for improving the drivability of existing motor vehicles so that the aforementioned disadvantages can be eliminated. Summary of the invention

[0007] An object of the present invention is to propose a new and advantageous method for improving the driving behavior of a motor vehicle.

[0008] Another object of the invention is to propose a method, a device and a computer program for improving the driving behavior of a motor vehicle.

[0009] A further object of the invention is to propose a method and a computer program for carrying out a user-friendly method for improving the driving behavior of a motor vehicle.

[0010] These objects are achieved by a method for improving the driving behavior of a motor vehicle, which comprises the steps according to claim 1.

[0011] Advantageously, this makes it possible to prevent incorrect gearshifting. This innovative process prevents the driver from allowing the vehicle clutch to slide together before a new gear has been engaged.

[0012] A first state of the clutch may mean that the clutch of a vehicle's power transmission is fully open, resulting in an interruption of power in the vehicle's power transmission.

[0013] A second condition of the clutch may mean that the clutch is not fully open.

[0014] Any desired gear level can be a preselected gear level.

[0015] The method may further comprise the step of indicating to a driver that a gear other than neutral of the transmission is engaged, which allows control of the vehicle engine and transmission to be returned to a driver of the vehicle. The use of presentation means to provide confirmation to the driver that a gear other than neutral of the transmission is engaged makes it possible to avoid the use of an expensive gear lever with a confirmation function. The method according to one aspect of the invention can thus represent a cost-effective solution to the problem of improving the drivability of a motor vehicle.

[0016] The method is easy to implement in existing motor vehicles. According to the invention, software for automatically deactivating and activating operating devices during a gearshift operation, for example, the accelerator pedal and clutch pedal, based on an action taken by the driver can be installed in a vehicle control unit during vehicle manufacture. A purchaser of the vehicle can thus have the option of selecting the function of the method. Alternatively, software comprising program code for implementing the innovative method for improving the drivability of a motor vehicle can be installed in a vehicle control unit as part of an upgrade at a service center. In this case, the software can be loaded into a memory of the control unit.Implementing the innovative method is therefore cost-effective in several aspects, primarily because no additional buttons, keys, or electronic components need to be installed in the vehicle. Existing presentation means can be used to perform a confirmation function according to one aspect of the invention. The necessary hardware, for example, a vehicle control unit, is already provided in the vehicle. Therefore, the invention represents a cost-effective solution to the problem of improving the drivability of a motor vehicle.

[0017] Software that includes program code for improving a motor vehicle's handling is easy to update or replace. Different parts of the software that include program code for improving a motor vehicle's handling can also be replaced independently. This modular configuration is advantageous from a maintenance perspective.

[0018] The above-mentioned objects are also achieved by a device for improving the driving behavior of a motor vehicle, the device comprising the features according to claim 6. Advantageous embodiments are specified in the dependent claims 7 to 9.

[0019] The innovative device can allow a driver to have full control over the vehicle's engine and transmission, provided they release the clutch pedal after a new gear ratio has been initiated. When the driver begins to release the clutch pedal, a change from a first state (fully open position) to a second state (not fully open position) of the clutch is detectable. Confirmation that a new gear ratio has been initiated can be provided via the presentation means.

[0020] If the vehicle driver releases the clutch too early during a gearshift, i.e., before a new gear has been initiated, a control unit of the vehicle is configured to assume control of the gearshift and ensure that the gearshift is performed without damage to a transmission of the vehicle. The control unit is also configured to transfer control of the engine and transmission to the driver in a predetermined manner after a preselected gear has been correctly engaged. The transfer of control to the driver preferably takes place in a controlled manner, with a prevailing engine torque being increased up to an engine torque requested by the driver.

[0021] These objects are also achieved by a motor vehicle comprising the features according to claim 10. The motor vehicle may be a truck, bus, or passenger car.

[0022] These objects are also achieved by a computer program for improving the driving behavior of a motor vehicle, wherein the computer program comprises program code stored on a computer-readable medium in order to allow an electronic control unit or another computer connected to the electronic control unit to carry out the steps specified in claims 1 to 5.

[0023] These objects are also achieved by a computer program product comprising a program code stored on a computer-readable medium to carry out the method steps according to claims 1 to 5.

[0024] Additional objects, advantages, and novel features of the present invention will become apparent to one skilled in the art from the following details and from the practice of the invention. While the invention is described below, it is to be understood that the invention is not limited to the specific details disclosed. Those skilled in the art having access to this teaching will recognize further applications, modifications, and connections to other fields within the scope of the invention. Brief description of the drawings

[0025] For a better understanding of the present invention and further objects and advantages thereof, the following detailed description should be read in conjunction with the accompanying drawings, in which the same reference numerals designate similar items throughout the several views and in which: Fig. Figure 1 schematically illustrates a vehicle according to an embodiment of the invention; Fig. 2 according to an embodiment of the invention, a subsystem for the Fig. 1 schematically represents the vehicle shown; Fig. 3 is a schematic diagram showing how various parameters of the motor vehicle depend on time according to an embodiment of the invention; Fig. 4a is a schematic flow diagram of a method for improving the drivability of a motor vehicle according to an embodiment of the invention; Fig. 4b is a more detailed schematic flow diagram of a method for improving the drivability of a motor vehicle according to an embodiment of the invention; and Fig. 5 schematically illustrates a computer according to an embodiment of the invention. Detailed description of the drawings

[0026] Fig. 1 depicts a side view of a vehicle 100. The illustrated vehicle 100 includes a tractor unit 110 and a trailer 112. The vehicle may be a heavy vehicle, such as a truck or a bus. Alternatively, the vehicle may be a passenger car. The vehicle 100 is a motor vehicle with an automated transmission.

[0027] The term “connection” here refers to a communication connection, which may be a physical connection, such as an opto-electronic communication line, or a non-physical connection, such as a wireless connection, for example a radio link or microwave link.

[0028] Fig. 2 illustrates a subsystem 299 of vehicle 100. Subsystem 299 is located in tractor unit 110. Subsystem 299 has an engine 230. Engine 230 may be an internal combustion engine. The internal combustion engine may be a six-cylinder engine. The internal combustion engine may alternatively have four, five, or eight cylinders. The internal combustion engine may alternatively be a diesel engine. The internal combustion engine may alternatively be a gasoline, gas, or ethanol engine.

[0029] The engine 230 has a drive shaft 231 connected to a clutch 235. The clutch may, for example, be of a conventional disc type, such as a twin-disk clutch. The clutch 235 is also connected to a shaft 236. The shaft 236 is an input shaft to a transmission 240. The transmission 240 has a drive shaft 243 configured to transmit power from the engine to a number of vehicle wheels 245 in a conventional manner. The clutch 235 is configured to be capable of interrupting power transmission in the driveline of the motor vehicle 100, which driveline includes the shaft 231, the clutch 235, the shaft 236, the transmission 240, and the shaft 243. According to one version, a control unit 200 is configured to control both the clutch 235 and the transmission 240. The control unit 200 is configured to communicate with the clutch 235 via a connection 237.The control unit 200 is configured to communicate with the transmission 240 via a connection 239.

[0030] A second control unit 210 is configured to communicate with the control unit 200 via a connection 215. The second control unit 210 can be detachably connected to the control unit 200. The second control unit 210 can be a control unit outside the vehicle 100. The second control unit 210 can be configured to carry out the innovative method steps according to the invention. The second control unit 210 can be used to transmit software to the control unit 200, in particular software for carrying out the innovative method. Alternatively, the second control unit 210 can be configured to communicate with the control unit 200 via an internal network in the vehicle.The second control unit 210 may be configured to perform substantially similar functions as the first control unit, for example, controlling the engine 230, the clutch 235, and the transmission 240 based on information received from a controller 280.

[0031] According to this version, the control unit 200 is also designed to control the motor 230 via a connection 233.

[0032] The control unit 200 is signal-connected to first operating means 250 via a connection 251 or connected in another manner. The operating means 250 may be an acceleration control, for example, an accelerator pedal for manual intervention by a driver of the motor vehicle 100. The control unit 200 is configured, among other things, to control the engine 230 in response to manual intervention on the operating means 250.

[0033] The control unit 200 is signal-connected or otherwise connected to second operating means 260 via a connection 261. The operating means 260 comprise a clutch control, for example, a clutch pedal for manual intervention by a driver of the motor vehicle 100. The control unit 200 is configured to control the clutch 235 in response to manual intervention on the operating means 260.

[0034] Of course, separate control units can be provided for the engine and transmission. In this case, they must be interconnected to allow them to communicate relevant information between each other.

[0035] According to one version, the control unit 200 is configured to control the transmission 240 via a connection 239. For this purpose, the control unit 200 is signal-connected to operating means (not shown) for changing gears in the transmission.

[0036] The control unit 200 is signal-connected or otherwise connected to presentation means 270 via a connection 271. The presentation means 270 may be any type of visual presentation means, for example, a screen. According to one version, the presentation means 270 may be a light-emitting diode (LED). The presentation means 270 may be any type of light-generating presentation means that includes a loudspeaker for generating acoustic signals, for example, beep signals.

[0037] The presentation means 270 are configured to display, during a gearshift operation, a confirmation that a new gear has been engaged. The confirmation is an indication that the driver can release the clutch pedal 260 to allow the clutch 235 to slide together. The confirmation can be provided in any desired manner. According to one version, the confirmation takes the form of information comprising one or more alphanumeric characters displayed on the screen. According to one version, the confirmation takes the form of information comprising one or more symbols displayed on the screen. According to one version, the confirmation takes the form of a light beam of any desired color emitted by the LED. For example, a "green" color can indicate that a new gear has been engaged and that the driver can therefore safely release the clutch pedal.According to one example, the acknowledgment takes the form of any desired acoustic signal generated and output by the loudspeaker.

[0038] The presentation means 270 may also take the form of an audio-visual unit adapted to provide confirmation in any desired manner, for example by combined light and acoustic signals, that a new gear ratio has been engaged in the vehicle's transmission, so that a driver is aware that the clutch pedal can be released safely.

[0039] The presentation means 270 can be manually adjusted by a driver of the vehicle. This means that a specific type of desired feedback can be set by the driver of the vehicle. This can provide a "tailored" confirmation that a new gear has been engaged in the vehicle's transmission.

[0040] The control unit 200 is signal-connected or otherwise connected to a controller 280 for gear selection in the transmission 240 via a connection 281. The controller 280 may be a gearshift lever.

[0041] Fig. 3 is a schematic diagram showing how various parameters of the motor vehicle depend on time according to an embodiment of the invention.

[0042] In the figure, a continuous curve f represents the speed of the vehicle's engine. There is also a continuous curve e representing the position of the vehicle's clutch 235. A clutch position is associated with a position of the vehicle's clutch pedal.

[0043] Before time T31, a certain engine speed prevails. Before time T31, the clutch is closed, and the vehicle's drivetrain transmits the torque generated by the engine.

[0044] Two different cases are described below.

[0045] In the first case, the clutch in the drivetrain is fully disengaged at time T31. A selected gear is then engaged at time T42. After the new gear has been engaged, the driver can apply pressure to the clutch pedal and accelerator pedal so that the clutch begins to slide together at time T43. At time T34, the clutch is fully engaged. During a time period T31 to T43, the driver will keep the clutch pedal fully depressed to keep the vehicle's clutch fully disengaged. This first case is represented by the two continuous lines e and f.

[0046] In the second case, the clutch in the drivetrain is fully open at time T31. Thereafter, the driver releases the clutch pedal at time T41, i.e., before a new gear has been engaged, and the transmission will have engaged a neutral gear. According to the invention, this is detected, and a control unit of the vehicle takes over control of the gearshift process at this time. According to one example, the control unit will take over control of the gearshift process before the clutch has been engaged if it is detected that the driver releases the clutch pedal too early. The control unit preferably takes over control of the gearshift process when the driver has released the clutch pedal to a predetermined position relative to its fully depressed position. The predetermined position of the clutch pedal and its fully depressed position are preferably close to each other.According to this first case, the driver maintains control of the clutch pedal and the accelerator pedal.

[0047] According to the second case, the control unit is configured to assume control of the gearshift operation as above and engage the new gear. When the new gear is engaged at a time T44, control of the accelerator pedal is returned to the driver. The vehicle parameters of engine speed and clutch position are represented in the second case by the discontinuous curves f* and e*, respectively. According to this second case, the driver does not retain control of the engine and transmission if it is detected that he / she intends to release the clutch pedal during a gearshift operation before a selected gear has been engaged in the transmission, when a neutral gear of the transmission is engaged. Control of the accelerator pedal can be transferred to the driver after the new gear has been automatically engaged. The transfer is carried out in a controlled manner.

[0048] Fig. 4a is a schematic flow diagram of a method for improving the drivability of a motor vehicle during a gearshift operation, wherein there is a neutral position of a transmission of a vehicle's powertrain. The method comprises the step of determining when a first state of a clutch of the vehicle changes to a second state. Method step s401 optionally also comprises the steps of taking over control of an engine and transmission of the vehicle from a driver of the vehicle based on the determination in order to automatically control the gearshift operation such that any desired gear position of the transmission is engaged, and thereafter returning control of the engine and transmission of the vehicle to a driver. After step s401, the method ends.

[0049] Fig. 4b is a more detailed schematic flow diagram of a method for improving the drivability of a motor vehicle during a gearshift operation according to an embodiment of the invention, wherein there is a neutral position of a transmission of a vehicle's powertrain. The method comprises a first step s410. Step s410 comprises the step of determining whether a new gear position of the vehicle's transmission has been selected. Step s410 comprises the step of determining whether a neutral position of the transmission has been engaged. Step s410 comprises the step of determining whether a clutch pedal of the vehicle is fully depressed. If a new gear position of the vehicle's transmission has been selected and a neutral position of the transmission has been engaged and a clutch pedal of the vehicle is fully depressed, a subsequent step s420 is performed.

[0050] Method step s420 determines whether a driver is acting on the clutch pedal in such a way that it can be assumed that the clutch is to be closed, thereby providing power transmission in the vehicle drivetrain. If the driver is acting on the vehicle's clutch pedal in such a way, a subsequent step s430 is performed. If the driver is not acting on the vehicle's clutch pedal in such a way, the new gear ratio is expected to be engaged, and the method ends. According to one version, a signal is sent containing information that a new gear ratio has been engaged. This signal can be used to indicate to the driver that a new gear ratio has been engaged.

[0051] Method step s430 automatically transfers control of the engine and transmission from the driver to the control unit 200. The driver of the vehicle will thus no longer be able to influence the gearshift process using, for example, the clutch pedal and the accelerator pedal, but will still be able to use the gearshift lever to select new target gears. Step s430 is followed by step s440.

[0052] Process step s440 adjusts the engine speed to achieve a specific clutch engagement speed. Once the engine engagement speed has been reached, the new gear is engaged. Step s440 is followed by step s450.

[0053] Method step s450 automatically transfers control of the engine and transmission from control unit 200 to the driver. The vehicle driver can then resume control of the engine and transmission to steer the vehicle as desired. Step s450 is followed by step s460.

[0054] Method step s460 sends a signal containing information that a new gear has been engaged. This signal can be used to indicate to the driver that a new gear has been engaged. Step s460 is arbitrary. According to one example, no confirmation is sent to the driver, but it is implicitly understood that the driver must wait a sufficient period of time before attempting, for example, to select a new transmission gear. After that, the method ends.

[0055] Fig. 5 is an illustration of a version of a device 500. The control units 200 and 210 described with reference to Fig. 2, may, in one version, comprise the device 500. The device 500 comprises a non-volatile memory 520, a data processing unit 510, and a read / write memory 550. The non-volatile memory 520 has a first storage element 530 in which a computer program, for example, an operating system, is stored to control the function of the device 500. The device 500 further comprises a bus controller, a serial communication port, I / O means, an A / D converter, a time and date input and transmission unit, an event counter, and an interrupt controller (not shown). The non-volatile memory 520 also has a second storage element 540.

[0056] According to one aspect of the invention, a computer program P is provided that includes routines for improving the drivability of a motor vehicle during a gearshift operation, wherein there is a neutral position of a transmission of a vehicle's powertrain. According to the innovative method, the program P optionally includes routines for taking over control of the operating means 250 and 260 from a driver during a gearshift operation and for automatically controlling the gearshift operation such that any desired gear position of the transmission is engaged, and thereafter for returning control of the operating means 250 and 260 to a driver. The program P can be stored in an executable form or in a compressed form in a memory 560 and / or in a read / write memory 550.

[0057] Where it is stated that the data processing unit 510 performs a particular function, this means that the data processing unit 510 executes a particular part of the program stored in the memory 560 or a particular part of the program stored in the read / write memory 550.

[0058] The data processing device 510 can communicate with a data interface 599 via a data bus 515. The non-volatile memory 520 is provided for communication with the data processing unit 510 via a data bus 512. The separate memory 560 is provided for communication with the data processing unit 510 via a data bus 511. The read / write memory 550 is provided for communication with the data processing unit 510 via a data bus 514. The connections 233, 237, 239, 251, 261, 271, and 215 can, for example, be connected to the data interface 599 (see Fig. 2).

[0059] When data is received at the data interface 599, it is temporarily stored in the second memory element 540. Once received input data has been temporarily stored, the data processing unit 510 will be ready to perform code execution in a manner previously described.

[0060] Portions of the methods described herein may be performed by device 500 using data processing unit 510, which executes the program stored in memory 560 or read / write memory 550. When device 500 executes the program, the methods described herein are performed.

[0061] The foregoing description of the preferred embodiments of the present invention is for illustrative and descriptive purposes. It is not intended to be exhaustive or to limit the invention to the described variations. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and their practical applications, and thus to enable those skilled in the art to understand the invention for various embodiments and with various modifications consistent with the intended use.

Claims

[1] Method for improving the driving behavior of a motor vehicle (100; 110) during a gear shift operation, wherein there is a neutral stage of a transmission (240) of a power transmission of the vehicle, comprising the step - determining when a state of a clutch (235) of the vehicle (100; 110) changes from a first state to a second state, characterized by the steps - taking over control of an engine (230) of the vehicle (100; 110), optionally from a driver, on the basis of the determination, in order to automatically control the gearshift process in such a way that any desired gear position of the transmission is engaged, and - thereafter returning control of the engine (230) of the vehicle (100; 110) to a driver. [2] The method of claim 1, wherein the first state of the clutch (235) means that the clutch (235) of the power transmission of the vehicle (100; 110) is fully open, resulting in a power interruption in the power transmission of the vehicle (100; 110). [3] The method of claim 2, wherein the second state of the clutch (235) means that the clutch is not fully open. [4] A method according to any one of the preceding claims, wherein each desired gear ratio is a preselected gear ratio. [5] Method according to one of the preceding claims, further comprising the step - indicating that a gear other than the neutral gear of the transmission (240) is engaged, whereupon control of the engine (230) and transmission (240) of the vehicle (100; 110) can be returned to a driver of the vehicle. [6] Device for improving the driving behavior of a motor vehicle (100; 110) during a gear shift operation, wherein there is a neutral stage of a transmission (240) of a power transmission of the vehicle (100; 110), the device comprising: - means for determining when a state of a clutch (235) of the vehicle changes from a first state to a second state, characterized by - means for taking over control of an engine (230) of the vehicle (100; 110), optionally from a driver, on the basis of the determination, in order to automatically control the gearshift process in such a way that any desired gear stage of the transmission (240) is engaged, and - means for returning control of the engine (230) of the vehicle (100; 110) to a driver after any desired gear ratio has been engaged. [7] The device according to claim 6, wherein the first state of the clutch means that the clutch (235) of a power transmission of the vehicle (100; 110) is fully open, resulting in a power interruption in the power transmission of the vehicle. [8] The device according to claim 7, wherein the second state of the clutch (235) means that the clutch (235) is not fully open. [9] Device according to one of claims 6 to 8, further comprising - means for indicating that a gear position of the transmission other than the neutral position of the transmission is engaged, whereupon control of the engine (230) and transmission (240) of the vehicle (100; 110) can be returned to a driver of the vehicle. [10] Motor vehicle (100; 110) comprising a device according to one of claims 6 to 9. [11] Motor vehicle (100; 110) according to claim 10, which is either a truck, bus or passenger car. [12] A computer program (P) for improving the driving behavior of a motor vehicle, the computer program (P) comprising program code stored on a computer-readable medium for causing an electronic control unit (200) or another computer (210) connected to the electronic control unit (200) to carry out the steps according to any one of claims 1 to 5. [13] A computer program product comprising a program code stored on a computer-readable medium for performing the method steps according to any one of claims 1 to 5, wherein the program code is operated on an electronic control unit (200) or another computer (210) connected to the electronic control unit (200).

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