Method for determining an engaged gear in a manual transmission

Abstract

A method for determining an engaged gear in a manual transmission (41) of a vehicle (40) comprising a plurality of gears is described, wherein the vehicle (40) comprises an engine (44), the manual transmission (41) and at least one clutch (42). The method comprises the steps of determining a rotational speed of the engine (44) as a function of time, differentiating the determined rotational speed of the engine (44) with respect to time, determining a speed of the vehicle, determining the engaged gear (42) based on characteristic curves (21, 22) of the rotational speed of the engine (44) as a function of time for a plurality of gears, the rotational speed of the engine (44), the differentiation of the rotational speed of the engine (44) with respect to time and the speed of the vehicle at a fixed engagement rate of the clutch (42).

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for determining an engaged gear in a manual transmission of a vehicle comprising a plurality of gears. The invention further provides a method for operating a vehicle and a vehicle, in particular a motor vehicle. BACKGROUND

[0002] Currently, for a large number of vehicles with a manual transmission, the currently engaged gear of the closed drive train is calculated based on the ratio of the rotational speed of the engine and the speed of the vehicle. Examples thereof are disclosed in document US 6,937,932 B2 and document WO 2014 / 135831 A2. Processes of this kind are sufficient for the basic usability and comfort application of the vehicle, which proposes the engagement of a specific gear for different driving situations, also for increasing performance and / or fuel efficiency.

[0003] With the introduction of electronically controlled clutches and further complex applications for vehicles with a manual transmission, the information about the currently engaged gear or the gear to be engaged is becoming increasingly important. Some of the said applications benefit from very early or up-to-date gear information. One of the said applications includes a strategy resulting from an idling situation or a situation in which the vehicle is rolling.

[0004] In order to automatically synchronize the engine with the input shaft of the transmission, the gear ratio must be known. In the absence of the said synchronization without two clutch discs, a deceleration of the vehicle occurs, which the driver can perceive and which is not desired.

[0005] The exact position of the gear lever is usually detected using a special sensor. This is disclosed, for example, in document US 2012 / 0625427 A1. However, the said sensor leads to additional costs, additional weight and requires storage space. SUMMARY

[0006] Against this background, it is an object of the present invention to provide an advantageous method for determining an engaged gear and a method for operating a vehicle, in which in particular an additional sensor for gear detection can be omitted.

[0007] The object is achieved by a method for determining an engaged gear in a manual transmission of a vehicle as claimed in claim 1, a method for operating a vehicle as claimed in claim 7 and a vehicle as claimed in claim 13. The dependent claims contain further advantageous designs of the invention.

[0008] The method for determining an engaged gear in a manual transmission of a vehicle comprising a plurality of gears according to the present invention involves a vehicle comprising an engine, the manual transmission and at least one clutch. The method comprises the steps of determining, e.g. measuring, the rotational speed of the engine as a function of time. The determined, e.g. measured, engine rotational speed is differentiated with respect to time. In other words, the gradient is determined, e.g. calculated. The speed of the vehicle is determined, e.g. measured. The engaged gear is determined based on the engine rotational speed, based on the derivative of the engine rotational speed with respect to time, based on the speed of the vehicle and based on a characteristic curve of the engine rotational speed as a function of time for a plurality of gears at a fixed engagement rate of the clutch. During this the engaged gear can be calculated in particular.

[0009] The characteristic curve represents a graphical representation of two interdependent physical variables, which are characteristic of a component, assembly or device, in the present case the engaged gear of the transmission. The characteristic curve of the rotational speed of the engine is preferably determined as a function of time for a plurality of gears at a fixed engagement rate of the clutch or is determined beforehand for the vehicle used as part of the method. In other words, for each gear with a certain engagement rate of the clutch or together with the clutch disc, a characteristic engine rotational speed curve is preferably defined as a function of time. In principle, it is sufficient to have the characteristic curve available or to determine the characteristic curve for a plurality of gears.

[0010] Advantageously, the characteristic curve is available or defined for all forward gears. Preferably, the characteristic curve is defined or available for performing the method according to the invention for each available gear, i.e. for all gears. In the latter case, the characteristic curve can be determined beforehand and can be called up from a database to perform the method according to the invention.

[0011] Engaging the clutch of the moving vehicle with the initially engaged gear results in a slip between the two clutch discs. The engine is dragged by the mass of the vehicle. If the two rotational speeds are the same and the force on the clutch disc is large enough, the transmission is closed. The degree or size of the engine acceleration is related to the clutch slip. This means that the rotational speed or the rotational speed of the clutch disc surface on the vehicle side depends on the engaged gear and the speed of the vehicle. The energy of the clutch disc can be calculated using the mass of the vehicle and the time required for the clutch engagement. The more energy is transferred to or by the engine within the defined time, the higher the angular acceleration. By keeping the engagement rate of the clutch constant when engaging each gear, there is a characteristic rotational speed of the engine characteristic curve for each gear.

[0012] The gear position G can thus be represented as a function f(G = f(K(t), v(t), MF, MM, R) of the clutch position K as a function of time t, the speed v of the vehicle as a function of time t, the mass MF of the vehicle, the mass MM of the engine and the friction R. By defining and measuring all vehicle characteristics in this way, while taking into account the current driving situation, information about the engaging gear can be obtained before the clutch is fully engaged. This has the advantage that the risk of damage to vehicle components by engagement of an unsuitable gear is avoided.

[0013] The method according to the application has the advantage that the engaging gear can be determined without an additional sensor for detecting the gear lever position. This reduces the costs, weight and necessary storage space associated with an additional sensor.

[0014] In an advantageous variant, the method according to the application is carried out with an at least partially open drive train. Thus, the clutch can be at least partially disengaged when the method is carried out. In particular, the clutch can be fully open. This has the advantage that the determination of the engaging gear can also be carried out if the known calculation methods, which presuppose a closed drive train or an engaged clutch and are based on a calculation of the ratio of the rotational speed of the engine and the speed of the vehicle or the rotational speed of the wheels, cannot be reliably applied.

[0015] In another variant, the characteristic curve is calibrated while taking into account or while using simultaneously the mass of the vehicle and / or the inertia of the engine and / or the position of the clutch as a function of time. This has the advantage that a vehicle-specific or application-specific characteristic curve can be determined in this way. The result is that the determination of the engaging gear is made more precise and the reliability of the determination is increased.

[0016] The determination of the rotational speed of the engine as a function of time is preferably carried out within a specified time window. This determination is advantageously carried out within a time window of not more than 300 milliseconds (300 ms). A shorter time window is advantageous in this respect. Additionally or alternatively, the determination of the speed of the vehicle can be carried out within a specified time window, for example within a time window of not more than 300 milliseconds (300 ms). A shorter time window is also advantageous here.

[0017] The method for operating a vehicle according to the application involves a vehicle comprising an engine, a manual transmission having a plurality of gears and at least one clutch. The method comprises the following steps: opening or disengaging the clutch. Opening or disengaging the clutch means that the flow of force between the two clutch discs of the clutch is interrupted. Closing or engaging the clutch means that the flow of force between the two clutch discs of the clutch is established. After opening the clutch, a reduction in the vehicle speed is determined, for example measured, as a function of time. This can be done within a specified time window. The currently engaged gear is determined according to the method for determining the above-mentioned engaged gear. The clutch is closed or engaged to a specified position. The rotational speed of the engine is determined, for example measured, as a function of time. This is preferably carried out within a specified time window. The derivative of the rotational speed of the engine with respect to time is determined, for example calculated. This can also preferably be done within a specified time window. The gear to be engaged is based on the derivative of the rotational speed of the engine with respect to time determined in the previous step and on characteristic curves of the plurality of gears. The gear to be engaged is output, for example to a user interface. To this end, a signal can be output with the determined gear to be engaged.

[0018] The method has the advantage that it enables a gear recommendation to be output in a simple manner. In addition, it is inexpensive compared to other methods and is suitable for many applications.

[0019] In an advantageous design, the clutch used is an electronically controlled clutch. The manual transmission can be designed, for example, as an automated manual transmission. For example, a single-clutch transmission or a dual-clutch transmission can be used. In particular in connection with an electronically controlled clutch and / or an automated manual transmission, the method according to the application enables the gear selection to be adapted to the respective driving situation and optimized in terms of fuel efficiency.

[0020] The vehicle can in principle be a motor vehicle or a watercraft. For example, the motor vehicle can be a passenger motor vehicle, a truck, a motorcycle or a motorized bicycle.

[0021] The clutch position of the clutch specified within the scope of the method for operating a vehicle according to the application, at which the clutch is engaged, can preferably be determined adaptively, for example can be an adaptively learned position. This has the advantage that the specified position can be specific to the application.

[0022] In an advantageous design, the determination of the rotational speed of the engine as a function of time and / or the determination of the derivative of the rotational speed of the engine with respect to time and / or the determination of the gear to be engaged is carried out within a calibratable time window. The time window can be, for example, no more than 300 milliseconds (300 ms). A shorter time window is advantageous in this regard. The calibration of the time window has the advantage that the method can be adapted to the respective requirements and driving situations. In particular, as a result, the processing time can be optimized.

[0023] The vehicle according to the invention includes an engine, a manual transmission with multiple gears, at least one clutch, and a controller. The controller is designed to perform the aforementioned method according to the invention for determining the engaged gear and / or the aforementioned method according to the invention for operating the vehicle. In principle, the vehicle can be a motor vehicle (e.g., a passenger vehicle, truck, motorcycle, or motor bicycle) or a vessel. In principle, the vehicle according to the invention has the same advantages as the aforementioned method according to the invention.

[0024] In summary, the present invention offers the following advantages (particularly in relation to electronically controlled clutches): it optimizes the selection of the gear to be engaged and selects a gear that matches the appropriate situation. As a result, it avoids engine stalling when the gear is too high or too low.

[0025] Other features, properties, and advantages of the invention are described in detail below with reference to the accompanying drawings and exemplary embodiments. All features described above and below, whether individually or in any combination thereof, are advantageous for this purpose. However, the exemplary embodiments described below are merely examples that do not limit the scope of the invention. Attached Figure Description

[0026] Figure 1 The method for determining the engagement position according to the present invention is schematically illustrated in the form of a flowchart;

[0027] Figure 2 This schematically illustrates the dependence of engine speed on time in two gears;

[0028] Figure 3 A method for operating a vehicle according to the present invention is schematically illustrated in the form of a flowchart;

[0029] Figure 4 A motor vehicle according to the present invention is shown schematically. Detailed Implementation

[0030] The following uses Figure 1 The flowchart shown details a method according to the present invention for determining the engaged gear in a manual transmission. In step 1, the engine speed as a function of time is determined (e.g., measured). In step 2, the engine speed determined in step 1 is differentiated with respect to time. In step 3, the vehicle speed is determined (e.g., measured). In step 4, the engaged gear is determined (e.g., calculated) based on a characteristic curve of the engine speed at a specific gear, the engine speed, the differential of the engine speed with respect to time, and the vehicle speed.

[0031] The steps can be carried out individually or collectively within a specified time window, for example within 300 milliseconds or less. The powertrain can be at least partially open while the method for determining the engaged gear is carried out. The clutch can also be at least partially disengaged.

[0032] For a plurality of gears, a characteristic curve of the engine speed as a function of time is determined for the case of a fixed engagement rate of the clutch, i.e. for a specified engagement rate of the clutch or a specified rate at which the clutch plates are brought together. The characteristic curve can be determined in this process. It can also be preferable to first determine the characteristic curve for the respective vehicle before the method according to the application is applied and can be recorded as data used during the method according to the application. The characteristic curve can be calibrated while taking into account / using the mass of the vehicle and / or the inertia of the engine and / or the position of the clutch as a function of time.

[0033] Figure 2 The dependency of the engine speed n in revolutions per minute (1 / min) on the time t in seconds (s) is schematically shown for two gears. In the example shown, curve 21 represents the engagement of the third gear and curve 22 represents the engagement of the fifth gear. The detection window is characterized by reference sign 23.

[0034] The method for operating a vehicle according to the application is described in detail below using the flowchart shown in Figure 3 The initial situation of step 31 is a vehicle in a roll with a disengaged clutch. In step 32, a reduction in the vehicle speed as a function of time is determined, in particular measured. This can be carried out within a specified time window. In step 33, the engaged gear can be determined by means of the method described in connection with Figure 1 The method described determines the engaged gear. In step 34, the clutch is engaged or closed to a specified position. This can be an adaptively learned position.

[0035] In step 35, the rotational speed of the engine as a function of time is determined and the differential of the rotational speed with respect to time is determined, for example calculated, and analyzed. This can be carried out within a specified time window. During the analysis, the gear to be engaged is determined on the basis of the differential of the rotational speed of the engine with respect to time and the characteristic curve. In step 36, the recommendation of the gear to be engaged is output to, for example, a user interface.

[0036] In Figure 4In the middle, a motor vehicle 40 according to the application is shown schematically. The motor vehicle 40 can be a passenger motor vehicle, a truck, a motorcycle or a motorized bicycle. The motor vehicle 40 comprises an engine 44 and a manual transmission 41, for example an automated manual transmission. The manual transmission 41 can be designed as a single-clutch transmission or as a dual-clutch transmission. The motor vehicle further comprises a clutch 42, for example an electronically controlled clutch. The clutch 42 is functionally connected to the manual transmission 41 and to the engine 44 in the usual manner. Furthermore, the motor vehicle 40 comprises a controller 43 which is designed to carry out the method described above. To this end, the controller 43 is designed to transmit appropriate signals to the clutch 42 and / or to the manual transmission 41.

[0037] Reference signs

[0038] 1 Determining the engine speed as a function of time

[0039] 2 Determining the differential of the rotational speed with respect to time

[0040] 3 Determining the speed of the vehicle

[0041] 4 Determining the engaged gear

[0042] 21 Characteristic curve

[0043] 22 Characteristic curve

[0044] 23 Detection window

[0045] 31 The vehicle is rolling, wherein the clutch is disengaged

[0046] 32 Determining a reduction in the speed of the vehicle as a function of time

[0047] 33 Determining the engaged gear

[0048] 34 The clutch is engaged to the specified position

[0049] 35 Determining the rotational speed of the engine with respect to time and its differential, determining the engaged gear

[0050] 36 Outputting a gear recommendation

[0051] 40 Motor vehicle

[0052] 41 Manual transmission

[0053] 42 Clutch

[0054] 43 Controller

[0055] 44 Engine

Claims

1. A method for determining an engaged gear in a manual transmission (41) of a vehicle (40) comprising a plurality of gears, wherein, The vehicle (40) comprises an engine (44), the manual transmission (41) and at least one clutch (42), characterized in that the method comprises the following steps: - determining characteristic curves (21, 22) of the rotational speed of the engine (44) as a function of time for a plurality of gears at a fixed engagement rate of the clutch, - at least partially disengaging the clutch (42), - determining a reduction of the speed of the vehicle (40) as a function of time, - determining the rotational speed of the engine (44) as a function of time, - differentiating the determined rotational speed of the engine (44) with respect to time, - determining the speed of the vehicle, and - determining the engaged gear on the basis of the characteristic curves (21, 22) of the rotational speed of the engine (44) as a function of time for a plurality of gears at a fixed engagement rate of the clutch, the rotational speed of the engine (44), the differentiation of the rotational speed of the engine (44) with respect to time and the speed of the vehicle.

2. The method according to claim 1, characterized in that for a plurality of gears, the characteristic curves of the rotational speed of the engine (44) are determined as a function of time at a fixed engagement rate of the clutch (42).

3. The method according to claim 1, characterized in that the characteristic curves are calibrated using the mass of the vehicle (40) and / or the inertia of the engine (44) and / or the position of the clutch (42) as a function of time.

4. The method according to claim 1, characterized in that the determination of the rotational speed of the engine (44) as a function of time and / or the determination of the speed of the vehicle is performed within a specified time window.

5. The method according to claim 4, characterized in that the determination of the rotational speed of the engine (44) as a function of time and / or the determination of the speed of the vehicle is performed within a time window of not more than 300 milliseconds.

6. A method for operating a vehicle, the vehicle comprising an engine (44), a manual transmission (41) having a plurality of gears and at least one clutch (42), characterized in that the method comprises the following steps: - disengaging the clutch (42), - determining a reduction of the speed of the vehicle (40) as a function of time, - determining the currently engaged gear according to the method of any one of claims 1 to 5, - engaging the clutch (42) to a specified position, - determining the rotational speed of the engine (44) as a function of time, - determining the differentiation of the rotational speed of the engine with respect to time, - determining the gear to be engaged on the basis of the differentiation of the rotational speed of the engine with respect to time determined in the preceding step and on the basis of characteristic curves for a plurality of gears, and - outputting the determined gear to be engaged.

7. The method according to claim 6, characterized in that The clutch (42) used is an electronically controlled clutch.

8. The method according to claim 6, characterized in that The manual transmission (41) is designed as an automated manual transmission.

9. The method according to claim 6, characterized in that A single-clutch transmission or a dual-clutch transmission is used.

10. The method according to claim 6, characterized in that The specified position of the clutch (42) is an adaptively determined position.

11. The method according to claim 6, characterized in that Determining the rotational speed of the engine (44) as a function of time and / or determining the derivative of the rotational speed of the engine (44) and / or determining the gear to be engaged is carried out within a calibratable time window.

12. A vehicle (40) comprising an engine (44), a manual transmission (41) having a plurality of gears, at least one clutch (42) and a controller (43), characterized in that The controller (43) is designed to carry out the method according to any one of claims 1 to 11.

13. The vehicle (40) according to claim 12, characterized in that The vehicle (40) is a motor vehicle or a watercraft.

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