TWI599511B - Position sensing device for pedal crank shaft of electrically assisted bicycles. - Google Patents

Description

Electric bicycle bicycle pedal crank position sensing device

The invention provides a foot crank shaft position sensing device for an electric bicycle, in particular to a position sensing system which is directly or indirectly connected to a pedal crank shaft, and can detect the pedal crank in each A torque detecting unit, a processing unit, and an electric assist driving method for the pedaling torque subjected to the rotating angle; the exact rotation angle of the pedal crank, the corresponding pedaling torque value, and the setting of the ideal torque curve value By means of the processing unit, the electric assist motor outputs a precise electric assist torque to assist the pedal crank shaft to compensate for the pedaling torque detected by the torque detecting unit, so that the user's pedaling torque can be equal to the ideal setting. The value of the torque curve, in turn, improves the stability of the output power of the electric bicycle when riding, and the comfort of the user when stepping on the pedal.

Based on the need for environmental protection and riding easily and comfortably, there are many different electric bicycles on the market, and the pedaling torque control is one of the main electric assist control methods.

In order to improve the stability of the output power of the knight when riding the electric bicycle, and the comfort when stepping on the bicycle, the electric bicycle with the treading force detection device should have a corresponding pedal crank per 360 degrees. The ideal torque curve value of a rotation angle, and the ideal electric assist control is to control the electric assist torque provided, so that the rider's pedal torque when riding the electric vehicle is the same as the ideal torque curve; However, there are currently no electric bicycles that meet the above ideal conditions. Most of the existing ones have only one pair of position sensors. After the timer and the processing unit are matched, the rotational speed and rotation angle of the pedal crankshaft are calculated. However, the origin of the rotation angle is not set, and the rotation angle of the pedal crankshaft can be recalibrated every revolution; therefore, it does not provide accurate electric torque, and the electric torque is often only provided. Multiply the measured torque value by a score of 1 or less and adjust it.

The design of the pedal position sensor to detect the rotation angle of the crankshaft is disclosed in "AUTOMATIC GEAR-SHIFTING BICYCLE WITH OPTIMAL SHIFT TIMING", which is mainly used in the process of pedaling. , let the microcomputer find out that the crank is the best gear shift time at the time of stepping on the dead point (the position of 0 degree angle and 180 degree angle with respect to the horizontal plane, that is, the position of the fourth picture point 4 and point 8), or It is the best shift timing when anti-stepping; this design is not related to torque detection and electric assist torque.

In the case of No. 20130054102, a pair of pedal position sensors are also provided to detect the rotation angle and the rotation speed of the crankshaft, and the angle zeroing and calibration cannot be performed, so that the missing of the stepping dead point is caused; It is only used to avoid the shifting position of the transmission when the user steps on the pedal, so as to avoid the situation that the shifting gear is not properly engaged when stepping on, but it still does not have the appropriate electric power according to the position of the user to step on.

In addition, an encoder having a rotation angle and a rotation direction for detecting a rotating shaft is also widely applied to a mobile platform such as a machine tool; however, the encoder is mainly composed of an optical position sensor, and the function required is to detect the rotating shaft. The direction of rotation and the cumulative angle of rotation are converted into moving distances.

In view of this, our inventors have devote themselves to further research on electric bicycles, and have begun research and development and improvement, with a better invention to solve the above problems, and have been experimentally and modified to have the present invention.

In order to achieve the above object, the inventors provide a pedal-cranking position sensing device for an electric bicycle, comprising: a pedal crank shaft having a pedal crank at each end thereof; a position sensing system, The method includes at least two sets of position sensors, and defines at least one calibration point corresponding to the pedal crank shaft, and the position sensor is directly or indirectly coupled to the pedal crank shaft, thereby detecting the foot a rotation angle of the crankshaft, a calibration point and a rotation direction; the calibration point is used to set an origin of the rotation angle; and a torque detection unit detects that the pedal crank is subjected to each rotation angle a stepping torque; and a processing unit electrically coupled to the position sensing system, the torque detecting unit, a timer, and an electric assist motor; the processing unit is configured to correspond to the pedal crank The ideal torque curve value of a rotation angle; thereby, the invention can make the electric motor through the processing unit according to the exact rotation angle of the pedal crank, the corresponding pedaling torque value and the set ideal torque curve value. A precise electric assist torque is applied to the crankshaft to compensate for the pedaling torque detected by the torque detecting unit, so that the user's pedaling torque can be equal to the set ideal torque curve value; The stability of the output power and the comfort of the user when stepping on.

According to the pedal-cranking position sensing device of the electric bicycle, the position sensor is selected from the group consisting of an electromagnetic sensor (Hall sensor, metal sensor), and optical One or a combination of a sensor, an encoder, an infrared sensor, or a capacitive sensor.

The position of the position sensor is not limited, can be grouped together, or can be separated into different positions, and the position sensors are directly or indirectly connected to the pedal crank shaft; the position can be The center-mounted electric motor can be installed in the non-center motor system either inside or outside the motor.

The position sensing system may only include a position sensor having one or two calibration points, and a position sensor having a plurality of positioning points of the annular array, and the number of the points determined by the sensor is determined by the sensor. The rotation angle of the pedal crankshaft; the position sensor for calibration is to eliminate the possible crankshaft rotation angle error, and when the receiving end of the calibration position sensor detects the signal, it will immediately The crankshaft rotation angle is recalibrated to zero; and the crankshaft rotation angle can be calibrated one or two times per revolution of the crankshaft.

The position sensing system may also include three or more sets of position sensors to simultaneously detect the rotation angle, calibration point and rotation direction of the pedal crank shaft.

The processing unit of the present invention is electrically connected to the sensing system, the torque detecting unit, the timer and an electric motor respectively; the processing unit is provided with an ideal corresponding to the rotation angle of the pedal crank at each rotation angle. The torque curve value, whereby the invention can be based on the exact rotation angle of the pedal crank, the corresponding pedaling torque value and the set ideal torque curve value, so that the electric assist motor outputs accurate electric assist torque through the processing unit. The crankshaft is configured to compensate for the pedaling torque detected by the torque detecting unit, so that the user's pedaling torque can be equal to the set ideal torque curve value; thereby improving the stability of the output power when riding the bicycle, and the user For the comfort of stepping on.

According to the pedaling shaft position sensing device of the electric bicycle, there is further provided a calibration component, wherein the calibration point and the positioning point of the plurality of annular arrays are provided, and the position sensor is sensed. Positioning point, and determining the rotation angle of the pedal crankshaft according to the sensed number of the measured position points; and the other position sensor sensing the calibration point, thereby eliminating the rotation angle of the pedal crankshaft An error, and when the calibration point is sensed, the detected rotation angle of the pedal crankshaft is recalibrated to zero.

According to the pedal-cranking position sensing device of the electric bicycle, the calibration component is provided with two calibration points, so that the pedal crank shaft can be rotated once to calibrate the second detected pedal crank. The angle of rotation of the shaft.

The pedal-cranking position sensing device of the electric bicycle according to the above, wherein the calibration component further has a direction point of the plurality of annular arrays, and the direction point has a phase difference with the positioning point; The position sensor senses the direction point, and the direction of rotation of the pedal crank shaft is determined by the phase difference.

It is obvious from the above description and setting that the present invention has the following several advantages and effects, which are detailed as follows:

1. The rotation angle calibration function can be achieved every revolution of the invention, which can prevent the incorrect detection and calculation of the rotation angle, so as to prevent the electric motor from providing improper electric assistance at an incorrect rotation angle. Further, the safety and comfort of the present invention during riding can be ensured.

2. The processing unit of the present invention is provided with a plurality of sets of ideal control torque curve values corresponding to the rotation angle of the pedal crank shaft at each rotation angle, and the ideal torque curve is a control target torque curve value after being electrically assisted by the motor, which can be Adjusted for different rides.

3. The invention integrates a set of rotation angle sensing systems capable of achieving a rotation angle calibration function every revolution, and a torsion force detection capable of detecting the pedaling torque of the pedal crank at each rotation angle. An electric assist driving method for the unit, a processing unit, and an electric assist motor; according to the exact rotation angle of the pedal crank, the corresponding pedaling torque value, and the setting of the ideal torque curve value, the electric motor is output through the processing unit Accurate electric torque assisting is applied to the crankshaft to compensate for the pedaling torque detected by the torque detecting unit, so that the user's pedaling torque can be equal to the set ideal torque curve. The value, in turn, enhances the safety, stability and comfort of the present invention during riding.

1‧‧‧ pedal crankshaft

11‧‧‧ pedal crank

2‧‧‧Location sensing system

21, 21', 21" ‧ ‧ position sensor

3‧‧‧ calibration point

31‧‧‧Location points

32‧‧‧ Direction Point

4‧‧‧Torque detection unit

5‧‧‧Processing unit

51‧‧‧Timer

6‧‧‧Electric motor

7‧‧‧ calibration components

8‧‧‧Electric bicycle

81‧‧‧ pedal

82‧‧‧Front sprocket

83‧‧‧ Rear wheel

Fig. 1 is a schematic view showing the structure of a first embodiment of the present invention.

Figure 2 is a schematic cross-sectional view showing a first embodiment of the present invention.

Figure 3 is a schematic diagram of the ideal torque curve value and the treading torque of the present invention.

4 is a schematic view showing the rotation angle of the pedal crank, the calibration point, and the positioning point in the first embodiment of the present invention at a position of 0 degrees.

Fig. 5 is a view showing the state of use of the bicycle when riding the electric bicycle according to the first embodiment of the present invention.

Figure 6 is a schematic view showing the rotation angle of the pedal crank, the calibration point, and the positioning point in the first embodiment of the present invention at a position of 120 degrees.

Figure 7 is a schematic cross-sectional view showing a second embodiment of the present invention.

Figure 8 is a schematic view showing the pedal crank, the positioning point, and the position sensor of the second embodiment of the present invention at a position of 120 degrees, and the calibration point is at a fixed position.

Figure 9 is a schematic cross-sectional view showing a third embodiment of the present invention.

Figure 10 is a schematic view showing the rotation angle of the pedal crank, the calibration point, the positioning point, and the direction point of the third embodiment of the present invention at a position of 120 degrees.

11 is a schematic view showing the rotation angle of the pedal crank, the calibration point, the positioning point, and the direction point in the fourth embodiment of the present invention at a position of 120 degrees.

The invention has been described in detail with reference to the preferred embodiments of the invention.

Referring to FIG. 1 to FIG. 6 , which is a first embodiment of the present invention, the present invention is a pedal-cranking position sensing device for an electric bicycle, comprising: a pedal crank shaft 1; Each of the two ends is provided with a pedal crank 11; a position sensing system 2, the entire group comprising at least two sets of position sensors 21, 21', and defining at least one calibration point 3 corresponding to the pedal crankshaft, and The position sensor 21, 21' is directly or indirectly coupled to the pedal crank shaft 1 to detect the rotation angle of the pedal crank shaft 1, the calibration point 3 and the rotation direction; The origin of the rotation angle is set; in addition, the position sensor 21, 21' is selected from an electromagnetic sensor (Hall sensor, metal sensor), optical sensor One or a combination of an encoder, an infrared sensor or a capacitive sensor; therefore, the position sensing system 2 can be a single type or a combination of different position sensors 21, 21' a torque detecting unit 4 for detecting the pedaling torque of the pedal crank 11 at each rotation angle In an embodiment, the torsion detecting unit 4 can be disposed on the pedal crank shaft 1 to measure the torque of the pedal crank 11, but is not limited thereto; and a processing unit 5 Electrically coupled to the position sensing system 2, the torque detecting unit 4, a timer 51, and an electric motor 6; the processing unit 5 is set to have an ideal angle corresponding to the pedal crank 11 at each rotation angle. Torque curve value; the position of the position sensors 21, 21' is not limited in the present invention, and may be grouped together or separated by different devices, and the position sensors 21, 21' are It will be directly or indirectly connected to the pedal crankshaft 1; the position can be inside or outside the electric motor 6 in the middle, or it can be installed In the present embodiment, the position sensors 21, 21' are all disposed inside the electric motor 6, which can prevent the position sensors 21, 21' from being affected by external forces and affecting their interpretation or damage. .

The position sensing system 2 detects the rotation angle by providing a calibration component 7 so that the calibration component 7 is directly or indirectly connected and synchronously rotated to the pedal crankshaft 1, and the calibration point 3 is provided. The positioning point 31 of the plurality of annular arrays, wherein the position sensor 21' senses the positioning point 31, and determines the rotation angle of the pedal crank shaft 1 according to the number of sensing points 31 sensed; The other position sensor 21 senses the calibration point 3, thereby eliminating the rotation angle error of the pedal crankshaft 1, and detecting the detected pedal crank when sensing the calibration point 3. The rotation angle of the shaft 1 is recalibrated to zero; and the calibration point 3 of the position sensing system 2 is provided with two in this embodiment, and is separated by 180 degrees, so that each rotation of the pedal crank shaft 1 is It can be calibrated twice; in another preferred embodiment, in order to improve the convenience and accuracy of the sensing, at least one of the position sensors 21, 21' can be set as a non-contact sensor, wherein The non-contact sensor can be a Hall sensor, a metal sensor, and an optical sensor. , encoder, infrared sensor or capacitive sensor; therefore, when the position sensor 21, 21' is a Hall sensor, the calibration point 3 and the positioning point 31 is a magnetic component; and if the position sensors 21, 21' are metal sensors, the calibration point 3 and the positioning point 31 are metal components; and the position sensors 21, 21' are optical sensors. The calibration point 3 and the positioning point 31 are reflective elements or optical encoders (ENCODER); the position sensors 21, 21' are capacitive sensors, and the calibration point 3 and the positioning point 31 are electrode units. However, it is merely illustrative and is not limited thereto. The types of position sensors 21, 21' may include, but are not limited to, the aforementioned non-contact sensors, and in addition, the position sensors 21, 21' Can be a contact sensor.

The processing unit 5 compensates the electric assist motor 6 for an electric assist torque according to the rotation angle, wherein the electric assist torque is a difference between the stepping torque and the ideal torque curve value in the rotation angle; In an embodiment, the ideal torque curve value can be set to the waveform curve disclosed in FIG. 3, and the ideal torque curve value can only set the torque change of the pedal crank 11 for one rotation, and of course, the ideal torque can also be used. The curve value is set to change the torque of the pedal crank 11 by half a rotation. However, since the user is stepping on the pedal 81 of the electric bicycle 8 by the left and right interaction, the pedaling force applied by the left and right feet is usually not equal, so the pedal is still set. The torque of the crank 11 is preferably changed by one rotation; and the ideal torque curve value can be obtained by directly measuring the waveform function, and can also be measured by the user when the motor is not driven by the electric motor 6 The torque of one pedal crank 11 is changed by one rotation, wherein the ideal torque curve value is from the maximum value to the minimum value, and the other pedal crank 11 is in the lifting stage of 45 degrees to 135 degrees, so the electric assist torque can be defined. The difference between the pedaling torque and the absolute value of the ideal torque curve value in the rotation angle.

And as shown in FIG. 4, when the calibration point 3 is set to correspond to the pedal crank 11 being 0 degrees, the position sensor 21 is aligned with the calibration point 3 when the pedal crank 11 is 0 degrees. The electric assist torque that the electric assist motor 6 wants to output is determined from the 0 degree of the waveform curve shown in FIG. 3; therefore, in order to allow the user to drive the electric bicycle 8 at the initial stage, the pedal 81 is stepped on the pedal. When the crank 11 is actuated, that is, the origin of the rotation angle is calibrated or reset to zero, and then the electric assist motor 6 compensates for the electric assist torque, so the position sensors 21, 21' can be set between 0 and 90 degrees. The angle is because the user is more inclined to apply force to the pedal crank 11 between the angles, but is not limited thereto.

As shown in FIGS. 5 and 6, when the user steps on the pedal crank 11 and transmits the pedal sprocket 8 through the pedal crank shaft 1 to drive the rear wheel 83 of the electric bicycle 8 As will be described above, the calibration element 7 will rotate in synchronization with the pedal crank shaft 1 so that the position sensor 21 senses the calibration point 3 in one direction, and the position sensor 21 ′ starts to sense the positioning point 31 . The timer 51 also starts counting, whereby the processing unit 5 determines the rotation angle of the pedal crank 11 at each time point, and when the rotation angle is obtained, the torque detecting unit 4 also measures simultaneously. To the pedaling torque of the pedal crank 11 at the rotation angle, it is assumed that the pedaling torque is a double-point chain line as shown in FIG. 3, and it is assumed that the rotation angle of one of the pedal cranks 11 is approximately At the position of 120 degrees, as shown in FIG. 3, the processing unit 5 is at a position of 120 degrees of rotation, and the pedaling torque at this time is deducted from the ideal torque curve value corresponding to the time to obtain the electric torque assisting force τ _{0 .} Therefore, the processing unit 5 causes the electric motor 6 to compensate for the current rotation angle. Torque, by repeating, allows the user to apply the actual pedaling force at each rotation angle equal to the ideal torque curve value on any road surface, thereby improving the comfort of the present invention during pedaling, and electricity The stability and safety of the drive.

Continuing to refer to FIG. 7 and FIG. 8 , which is a second embodiment of the present invention, which differs from the first embodiment in that the position sensor 21 ′ and the calibration element 7 are disposed on the electric motor 6 . Internally, and the calibration element 7 is only provided with the positioning point 31; the other position sensor 21 is arranged and slaved to the pedal crank 11, and the calibration point 3 is set outside the electric motor 6, due to the calibration element 7 And the pedal crank 11 is synchronously rotated by the pedal crankshaft 1; therefore, in the present embodiment, the position sensor 21' is fixed in position, and only the positioning point 31 will be rotated by the calibration element 7 by the position sensor. 21' sensed; the position sensor 21 is inductively fixed to the calibration point 3 outside the electric motor 6 by the rotation of the pedal crank 11, so the embodiment can also sense and calibrate the rotation angle as described above. The remaining embodiments of the present embodiment are similar to the first embodiment, and therefore are not described herein.

Continuing to refer to FIG. 9 and FIG. 10, which is a third embodiment of the present invention, which differs from the first embodiment in that the calibration element 7 of the present embodiment further has a direction point 32 of a plurality of annular arrays. And the direction point 32 has a phase difference with the positioning point 31; and the embodiment is provided with three sets of position sensors 21, 21', 21", and the position sensor 21" senses the a direction point 32, by which the direction of rotation of the pedal crank shaft 1 is determined by the phase difference, such as clockwise or counterclockwise rotation, The rest of the embodiments of the present embodiment are similar to those of the first embodiment, and thus are not described herein.

The fourth embodiment of the present invention is as shown in FIG. 11, which is different from the third embodiment in that the position sensor 21 of the present embodiment is disposed in the setting and is as shown in the second embodiment. The pedal 11 is moved to sense the calibration point 3 disposed outside the electric motor 6 , and the rotation direction of the pedal crank shaft 1 is also determined by using the phase difference; the rest of the embodiments are It is similar to the third embodiment, so it will not be described here.

In summary, the technical means disclosed by the present invention can effectively solve the problems of the prior knowledge, achieve the intended purpose and efficacy, and are not found in the publication before publication, have not been publicly used, and have long-term progress, The invention referred to in the Patent Law is correct, and the application is filed according to law, and the company is invited to give a detailed examination and grant a patent for invention.

The above is only the preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, that is, the equivalent changes and modifications made by the scope of the invention and the contents of the invention are all It should remain within the scope of this invention.

1‧‧‧ pedal crankshaft

2‧‧‧Location sensing system

4‧‧‧Torque detection unit

5‧‧‧Processing unit

51‧‧‧Timer

6‧‧‧Electric motor

Claims (7)

A pedal-cranking position sensing device for an electric bicycle includes: a pedal crank shaft having a pedal crank at each end thereof; a position sensing system including at least two sets of position sensors, and Defining at least one calibration point corresponding to the pedal crank shaft, and the position sensor is directly or indirectly coupled to the pedal crank shaft, thereby detecting the rotation angle, calibration point and rotation of the pedal crank shaft The calibration point is used to set the origin of the rotation angle; a torque detection unit detects the pedaling torque of the pedal crank at each rotation angle; and a processing unit Electrically coupled to the position sensing system, the torque detecting unit, a timer, and an electric assist motor; the processing unit is configured to have an ideal torque curve value corresponding to the rotation angle of the pedal crank; The processing unit compensates an electric assist torque according to the rotation angle, and the electric assist torque is a difference between the pedaling torque and the ideal torque curve value in the rotation angle. The pedal-cranking position sensing device of the electric bicycle according to the first aspect of the invention, wherein the position sensor is selected from the group consisting of an electromagnetic sensor (Hall sensor, Hall sensor, metal sense) One or a combination of a sensor, an optical sensor, an encoder, an infrared sensor, or a capacitive sensor. The pedal crank position sensing device of the electric bicycle according to claim 1, wherein the position sensor is set or separated. The pedal-cranking position sensing device of the electric bicycle according to the first aspect of the invention, wherein the position sensor is directly or indirectly coupled to the pedal crank shaft, and the position sensing The device is disposed inside or outside the electric assist motor. The pedal crank position sensing device of the electric bicycle according to claim 1, further comprising a calibration component, wherein the calibration point and the positioning point of the plurality of annular arrays are provided, and the position sense is The detector senses the positioning point, and determines the rotation angle of the pedal crank shaft according to the sensed number of the measured position points; and the other position sensor senses the calibration point, thereby eliminating the foot The crankshaft shaft rotates by an angle error, and when the calibration point is sensed, the detected rotation angle of the pedal crankshaft is recalibrated to zero. The pedal-cranking position sensing device of the electric bicycle according to claim 5, wherein the calibration component is provided with two calibration points, so that the pedal crank shaft can be rotated once to calibrate the second detection. The angle of rotation of the crankshaft is measured. The pedal-cranking position sensing device of the electric bicycle according to the fifth aspect of the invention, wherein the calibration component further has a direction point of the plurality of annular arrays, and the direction point system and the positioning point have a phase difference; one of the position sensors senses the direction point, thereby determining the direction of rotation of the pedal crank shaft through the phase difference.