DE102017128147A1 - A method for generating a shift command for a gear shift of a vehicle with a pedal drive - Google Patents

Abstract

The invention relates to a method for generating a switching command for a gearshift of a vehicle with a pedal drive (1), wherein an angular position of a pedal crank (2, 2 ') of the pedal drive (1) is measured and a switching command is generated when the measured angular position with a shift position is arranged, which is arranged by a lead angle (V) before a predetermined dead center of the pedal crank (2, 2 '), in which a minimum of the torque (D, D') is reached, wherein a rotational speed of the pedal drive (1) measured and the shift position is calculated as a function of the measured speed. Furthermore, the invention relates to a device for generating a switching command for a gearshift of a vehicle with a pedal drive (1), with a position sensor (10) for measuring an angular position of a pedal crank (2. 2 ') of the pedal drive (1), with an evaluation ( 11) for generating a switching command, when the measured angular position coincides with a switching position which is arranged by a lead angle (V) before a predetermined dead center position of the pedal crank (2, 2 '), in which a minimum of the torque (D, D') is achieved, and with a speed sensor (9) for measuring a speed of the pedal drive (1), wherein the evaluation electronics (11) is arranged to calculate the shift position in dependence on the measured speed.

Description

The invention relates to a method for generating a switching command for a gearshift of a vehicle with a pedal drive, wherein an angular position of a pedal of the pedal drive is measured, and a switching command is generated when the measured angular position coincides with a switching position by a lead angle before a vertical Position of the pedal is arranged. Furthermore, the invention relates to a method for operating a vehicle with a pedal drive and a gearshift. In addition, the invention relates to a device for generating a shift command for a gearshift of a vehicle with a pedal drive, with a position sensor for measuring an angular position of a pedal of the pedal drive, and with an evaluation for generating a switching command, when the measured angular position coincides with a switching position, which is arranged by a lead angle in front of a vertical position of the pedal.

The invention may find application in vehicles with a pedal drive, such as bicycles, Pedlecs and bio-hybrid light vehicles. Such pedal drives usually have several cranks, which are offset by the feet of a user in a rotary motion. Pedal drives typically show a sinusoidal torque curve. In a bicycle, maximum torque is typically achieved when the cranks of the pedal are horizontally aligned and a minimum when the cranks are vertically aligned. The position in which the torque reaches its minimum is also referred to as the dead center position.

In the WO 2015/035990 A1 It is proposed to detect the position of a pedal with a pedal sensor and to trigger a gear change when the crank is in the vicinity of its dead center position in order to keep the torque acting on the gearshift as small as possible. In this way, the wear caused by switching operations can indeed be reduced. However, it has been found that in the in the WO 2015/035990 A1 described dead center position is not always taken reliably, resulting in the risk that arise when switching unwanted pops.

Against this background, the task is to reduce the risk of noise during the gear change.

To achieve the object, a method for generating a switching command for a gearshift of a vehicle with a pedal drive is proposed, wherein an angular position of a pedal of the pedal drive is measured, and a switching command is generated when the measured angular position coincides with a switching position, the by a lead angle is arranged in front of a predetermined dead center position of the pedal, in which a minimum of the torque is achieved, wherein a speed of the pedal drive is measured and the switching position is calculated in dependence on the measured speed.

Another object of the invention is a device for generating a switching command for a gearshift of a vehicle with a pedal drive, with a position sensor for measuring an angular position of a pedal of the pedal drive, with an evaluation for generating a switching command, when the measured angular position coincides with a switching position, which is arranged by a lead angle before a predetermined dead center of the crank, in which a minimum of the torque is achieved, and with a speed sensor for measuring a speed of the pedal drive, wherein the transmitter is adapted to calculate the shift position in dependence on the measured speed ,

In the method according to the invention and the device according to the invention, the speed of the pedal drive, for example by means of a speed sensor, measured and calculated the switching position in dependence on the measured speed. This has the advantage that the lead angle can be determined with increased accuracy. In particular, in the case of a sharply fluctuating speed curve, this results in a higher accuracy in the calculation of the switching position compared with the prior art. As a result, the shift can take place closer to the predetermined dead center position of the pedal, so that the torque applied during switching is as minimal as possible and a reduced noise is observed.

For the purposes of the invention, the predetermined dead center position is understood to be a position of the pedal crank, in which a minimum of the torque is achieved. In a bicycle, a first (top) dead center position may be given when the crank is vertical and a pedal articulated to the crank vertically above a bottom bracket the pedal drive is arranged. A second (lower) dead center position can be given to the bicycle when the crank is vertical and the pedal cranked on the pedal is arranged vertically below the bottom bracket shaft. In a recumbent, however, a first (near) dead center position may be given when the crank is horizontal and a pedal articulated on the pedal crank between the user and the bottom bracket of the pedal drive is arranged. A second (far) dead center position may be provided on the recumbent bike when the crank is horizontal and the pedal cranked on the crank is located beyond the bottom bracket shaft as viewed by the user. In other vehicles, such as hybrid light vehicles, the absolute position of the dead center positions between those of the bicycle and those of the recumbent can be arranged.

According to an advantageous embodiment of the invention, the angular position and / or the rotational speed is measured continuously. This allows a more accurate compared to the prior art detection of fluctuations and temporal changes in the rotational speed and the rotation angle are made possible. For measuring the angular position and / or the rotational speed, a material measure can be used which is co-rotating with a bottom bracket of the pedal drive. The material measure may have a pitch, for example in the form of lines. Such material measures are also referred to as encoder disk. It is conceivable that the same measuring standard is used to measure the rotational speed and the angular position. Alternatively, different measuring standards can be used to measure speed and angular position. The position sensor can optically or magnetically scan a material measure. It is also possible that the speed sensor scans a material measure optically or magnetically. Particularly preferably, the rotational speed sensor and / or the position sensor scans a material measure with a plurality of divisions, so that in addition to the rotational speed and / or the angular position, the direction of rotation of the pedal drive can be detected.

It is preferred if the calculation of the shift position takes place as a function of a shift time of a shift mechanism of the gearshift. The shift time refers to the time that elapses for the implementation of a voltage applied to the gear shift of the vehicle shift command within the gear shift until the desired gear is engaged. The switching time is determined essentially by the switching speed of an actuator of the gearshift and the switching path of the actuator for the respective desired gear ratio. Therefore, the shift time is preferably calculated as a function of the engaged and / or transmitted with a gear change request gear. Alternatively, for several, in particular, all possible gear changes corresponding shift times may be stored in a memory and the corresponding shift time depending on the engaged and / or transmitted with a gear change request gear from the memory.

Alternatively or additionally, it is preferred if the calculation of the switching position is determined as a function of a signal propagation time of a transmitter. The signal propagation time of the evaluation electronics is understood to be the time which elapses for the measurement of the angular position of the pedal crank, if necessary for processing and for the evaluation of the measured value until the generation of the shift command for the gear shift of the vehicle. The signal transit time can be determined in a calibration process and stored in a memory. In this case, it is possible to read the switching time for calculating the switching position from the memory. It is particularly advantageous if both the switching time of the switching mechanism and the signal propagation time of the evaluation electronics are used to calculate the switching position.

To be advantageous, an embodiment has been found in which the shift command is only generated when in addition a gear change request to change to another gear is present, in particular a gear change request of a user or a control device. In this respect, a shift enable is generated by the calculation of the shift position, which then, when there is additionally a gear shift request, leads to the generation of a shift command for the gear shift. The gear shift request may be either manually by a user of the vehicle, for example by actuating an actuator. Alternatively, the gear change request can be generated automatically by a control device, for example a control device of a switchgear, without the intervention of the user of the vehicle being necessary.

Another object of the invention is a method for operating a vehicle with a pedal drive and a gearshift, in particular a hub gear, wherein the gearshift a switching command is supplied, which is generated by a method described above.

According to a preferred embodiment, the vehicle has an auxiliary drive, in particular an electric auxiliary drive, wherein the auxiliary drive is switched off for a predetermined switch-off time by means of the switching command. In this respect, it is possible to turn off the auxiliary drive synchronously with the achievement of the dead center position of the pedal. As a result, the torque generated by the auxiliary motor during the switching operation is minimal and the risk that caused by an applied torque of the auxiliary motor undesirable noise when switching is reduced.

In the method of operation for operating a vehicle with a pedal drive and a gear shift can alternatively or additionally to the described advantageous embodiments, the advantageous features are used alone or in combination, which have been described in connection with the method for generating the shift command for the gearshift.

• 1 ein Ausführungsbeispiel einer Vorrichtung zum Erzeugen eines Schaltbefehls für eine Gangschaltung eines Fahrzeugs mit einem Pedalantrieb in einer schematischen Schnittdarstellung;
• 2 eine schematische Seitenansicht eines Pedalantriebs zur Veranschaulichung der Bewegung der Tretkurbeln; und
• 3 eine beispielhafte Darstellung des Verlaufs des durch die Tretkurbeln des Pedalantriebes erzeugten Drehmoments in Abhängigkeit von der Winkelstellung der Tretkurbel.

Further details and advantages of the invention will be explained below with reference to the embodiment shown in the drawings. Hereby shows:

• 1 An embodiment of an apparatus for generating a shift command for a gear shift of a vehicle with a pedal drive in a schematic sectional view;
• 2 a schematic side view of a pedal drive to illustrate the movement of the cranks; and
• 3 an exemplary representation of the course of the torque generated by the pedal cranks of the pedal drive in dependence on the angular position of the pedal crank.

In the 1 is a schematic section of a trained as a bicycle vehicle with a pedal drive 1 which shows an exemplary embodiment of a device according to the invention for generating a switching command.

The pedal drive 1 has two cranks 2 . 2 ' on, with a first end each rotatably with a bottom bracket 4 of the pedal drive 1 are connected. The bottom bracket shaft 4 is over camp 5 , in particular roller bearings, mounted on the vehicle, for example a frame of the vehicle. The cranks 2 . 2 ' have a second end on which rotatably each a pedal 3 . 3. ' is articulated. The cranks 2 . 2 ' are arranged on the bottom bracket so that they enclose an angle of 180 ° with each other, see. also 2 , Every pedal 2 . 2 ' has a first (top) dead center position, in which the pedal crank 2 . 2 ' is vertical and the crank 2 . 2 ' hinged pedal 3 . 3. ' vertically above the bottom bracket 4 is arranged, and a second (bottom) dead center position in which the pedal crank 2 . 2 ' vertical stands and the pedals on the pedal crank 3 . 3. ' vertically below the bottom bracket shaft 4 is arranged. It takes a first pedal 2 their top dead center position when a second pedal crank 2 ' assumes its bottom dead center and vice versa, cf. 2 ,

The vehicle further includes a gearshift, not shown in the drawings, which may be arranged for example on a rear axle or rear hub of the vehicle. The device for generating a shift command for this gearshift has an in 1 shown position sensor 10 for measuring the angular position of the cranks 2 . 2 ' of the pedal drive. The position sensor 10 can be designed as an optical or magnetic position sensor. The position sensor 10 is fixedly arranged on the vehicle, for example on a frame, and scans a first material measure 8th off, with the bottom bracket axle 4 is arranged co-rotating. In this respect, via the position sensor 10 continuously the angular position of one or both cranks 2 . 2 ' be measured.

Another component of the device is a speed sensor 9 , about the speed of the pedal drive 1 , in particular the bottom bracket shaft 4 , is measured. The speed sensor 9 can be designed as an optical or as a magnetic speed sensor. The speed sensor 9 is fixedly arranged on the vehicle, for example on a frame, and scans a second material measure 7 off, with the bottom bracket axle 4 is arranged co-rotating. In this respect, via the speed sensor 9 continuously the speed of the pedal drive 1 be measured.

According to a modification of the embodiment shown, the position sensor 10 and the speed sensor 9 be integrated in a common sensor system. The common sensor system can scan a common material measure, in particular a material measure with several divisions.

The position sensor 10 and the speed sensor 9 are equipped with evaluation electronics 11 connected to the device. The evaluation electronics 11 is adapted to generate a switching command, when the measured angular position coincides with a switching position, which by a lead angle V is arranged in front of a predetermined dead center position of the crank, in which a minimum of the torque is achieved (here at 0 °, 180 ° or 360 °) and to calculate the shift position in dependence on the measured speed. Like the representation of the torque curves D the first pedal 2 and D ' the second pedal 2 ' in 3 can be seen, the switching command is generated in each case at a time in which the angular position of the pedal crank 2 . 2 ' either 0 ° -V, 180 ° -V or 360 ° -V. However, the transmitter generates 11 a shift command only if there is a gear shift request to change to another gear. Such a gear shift request may be predetermined by a user manually of the vehicle or automated by a controller connected to the transmitter.

For calculating the switching position or the lead angle V , be the switching time T2 a switching mechanism of the gearshift and the Signal propagation time T1 the transmitter determined. The lead angle V corresponding lead time corresponds to the sum of the signal propagation time T1 the transmitter and the switching time T2 the switching mechanism. Based on this lead time and the measured speed, the speed-dependent feed angle V determined, which is to be maintained, the shifting as accurately as possible in the dead center of the cranks 2 . 2 ' perform. The illustrations in 2 and 3 also show a switching range S around the respective dead center position.

The switching time T2 depends on the switching path at the desired gear change and the switching speed of the actuator used for gear change. In particular, the switching time T2 calculated as the ratio of the shift travel to the shift speed.

The signal transit time T1 is determined in a calibration process that precedes the operation of the device and stored in a memory. When the device receives a gear shift request, the signal transit time may be T1 be read from the memory and to calculate the lead time T1 + T2 or the lead angle V be used.

To calculate the switching position is also the with the speed sensor 9 measured speed of the pedal drive 1 used. It is assumed that the speed of the pedal drive 1 during the sweep of the lead angle V does not change or only very slightly. According to a first option, an average value of the measured rotational speed is determined, and based on this average value and the determined lead time T1 + T2, the advance angle V calculated. According to a second option, in addition to the lead time T1 + T2, the speed value for calculating the lead angle V be used, which is measured at a predetermined angular position of a pedal crank, z. B. at 0 °, 45 °, 90 ° or 120 °.

In the above-described method for generating a shift command for a gear shift of a vehicle with a pedal drive 1 becomes an angular position of a crank 2 . 2 ' of the pedal drive 1 measured and generates a switching command, when the measured angular position coincides with a switching position, the by a lead angle V before a predetermined dead center position of the crank 2 . 2 ' is arranged, in which a minimum of the torque D . D ' is reached. In the method, the speed of the pedal drive 1 measured and calculated the switching position as a function of the measured speed. During operation of the vehicle, the switching command generated in this way is supplied to the gearshift of the vehicle.

According to a modification, the vehicle additionally has an auxiliary drive, in particular an electric auxiliary drive, which is switched off for a predetermined switch-off time by means of the switching command. In this way, the risk that unwanted noise when switching arise again be reduced.

LIST OF REFERENCE NUMBERS

1

Cycle

2,2 '

crank

3,3 '

pedal

4

bottom bracket

5

roller bearing

6

chainring

7

Measuring standard

8th

Measuring standard

9

Speed sensor

10

position sensor

11

evaluation

D

Torque of pedal crank 2

D '

Torque of pedal crank 2 '

M

torque

S

switching range

T1

Signal propagation time

T2

switching time

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2015/035990 A1 [0003]

Claims (8)

A method for generating a shift command for a gearshift of a vehicle with a pedal drive (1), wherein an angular position of a pedal crank (2, 2 ') of the pedal drive (1) is measured and a switching command is generated when the measured angular position coincides with a switching position, is arranged by a lead angle (V) before a predetermined dead center position of the pedal crank (2, 2 '), in which a minimum of the torque (D, D') is achieved, characterized in that a speed of the pedal drive (1) measured and the switching position is calculated as a function of the measured speed. Method according to Claim 1 , characterized in that the angular position and / or the rotational speed are continuously measured, in particular by means of a material measure (7, 8) which is arranged mitdrehend with a bottom bracket (4) of the pedal drive (1), for example an encoder disc. Method according to one of the preceding claims, characterized in that the calculation of the switching position in response to a switching time (T2) of a switching mechanism of the gearshift takes place. Method according to one of the preceding claims, characterized in that the calculation of the switching position as a function of a signal delay time (T1) of a transmitter (11) is determined. Method according to one of the preceding claims, characterized in that the shift command is only generated when in addition a gear change request to change to another gear is present, in particular a gear change request of a user or a control device. A method of operating a vehicle with a pedal drive and a gearshift, in particular a hub gear, wherein the gearshift a switching command is supplied, which is generated by a method according to any one of the preceding claims. Method for operating a vehicle after Claim 6 , characterized in that the vehicle has an auxiliary drive, in particular an electric auxiliary drive, wherein the auxiliary drive is switched off for a predetermined switch-off time by means of the switching command. Device for generating a switching command for a gearshift of a vehicle with a pedal drive (1), with a position sensor (10) for measuring an angular position of a pedal crank (2. 2 ') of the pedal drive (1), and evaluation electronics (11) for generating a Switching command, when the measured angular position coincides with a switching position which is arranged by a lead angle (V) before a predetermined dead center position of the pedal crank (2, 2 '), in which a minimum of the torque (D, D') is reached, characterized by a speed sensor (9) for measuring a speed of the pedal drive (1), wherein the evaluation electronics (11) is adapted to calculate the shift position in dependence on the measured speed.

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