WO2017135716A1

WO2017135716A1 - Power assisted driving system and method

Info

Publication number: WO2017135716A1
Application number: PCT/KR2017/001163
Authority: WO
Inventors: 김정엽; 신동준
Original assignee: 중앙대학교 산학협력단; 서울과학기술대학교 산학협력단
Priority date: 2016-02-05
Filing date: 2017-02-03
Publication date: 2017-08-10

Abstract

According to one embodiment of the present invention, provided is a power assisted driving system comprising: a measurement part for measuring an operation state of a crank; a control part for determining a voltage or current necessary for power assistance on the basis of the measured value of the measurement part; a motor part, to which the voltage or current is applied, for providing driving power; and a power supply part for providing electric power to components other than itself.

Description

Power assist drive system and method

Embodiments relate to a power assisted drive system and method for increasing energy efficiency and enabling smooth acceleration of a driver in a driver that simultaneously uses human pedaling power and driver power, such as an electric bicycle.

In general, a bicycle is a two-wheeled vehicle that rotates a wheel through a crank-pedal mechanism when human force acts on a pedal, and is widely used for transportation, exercise, and leisure. Recently, as bicycle activation policies have been promoted nationally to reduce carbon emissions, which are the cause of global warming, the use of bicycles as a means of commuting as well as for sports and leisure is increasing rapidly.

These bicycles can be used by the elderly to reach their destination in a short time while consuming less stamina than running, so older people can use it without hesitation, but when there are many ramps, they have more physical strength than walking or running. In addition, if the distance to the destination is too far, so much physical strength has to be exhausted, rather it causes a problem that harms the user's health.

Electric bicycles, which are being used to solve these problems, are equipped with direct current motors and power assistance to wheel hubs of ordinary bicycles to provide a comfortable driving experience on flat and uphill roads.

The driver of a general electric bicycle can control the degree of power assistance of the DC motor provided in the electric bicycle by selectively using two methods, a throttle mode and a PAS (Pedal Assist System) mode.

The throttle mode is similar to the throttle lever used in a general motorcycle, and is mounted on the right handlebar of the electric bicycle and is pulled or released by the right handlebar of the electric bicycle. Speed, which is mounted on the so-called electric bicycle, plays a role of varying the torque value of the DC motor serving the auxiliary power function.

In the PAS mode, the electric bicycle driver controls the output of the motor through the pedaling operation, and can control the amount of torque for the power assist of the DC motor provided in the electric bicycle through a speed sensor that detects the rotation of the crankshaft when pedaling. .

The speed sensor using the Hall Effect is generally mounted on the crankshaft of the electric bicycle and detects the rotation of the crankshaft by the voltage generated by the Hall effect when the electric bicycle driver rolls the pedal.

The speed sensor torque control device used in the conventional electric bicycle is an on-off method for detecting only whether the driver rolls the pedal. When the voltage is detected by the speed sensor, the torque value of the DC motor of the electric bicycle is set to maximum. Let power assist However, since the existing electric bicycle assists the power in proportion to the RPM of the crankshaft measured from the Hall sensor, the power of the motor is rapidly reduced at low speed, when there is a problem that large power assistance is impossible when large power is required at low speed.

An alternative to the problem of the speed sensor method is the torque sensor method, but the torque sensor method is a mechanical method for measuring the distortion of the disc or spring generated during pedaling, and it is a high mounting cost and it is difficult to mount on a conventional electric bicycle. There is a need for an effective solution to control the motor output in proportion to the speed by the speed sensor method.

Patent document 1 proposed an electric bicycle torque control device that can control the torque of the motor variably according to the analog output signal of the speed sensor. According to patent document 1, the output of the motor is controlled in proportion to the pedaling speed, which is convenient. Although there was a side surface, the digital speed sensor composed of a double Hall sensor outputs a digital pulse signal, and thus, the method of Patent Document 1, which receives and uses an analog signal, has a problem that it is difficult to use a digital speed sensor.

In addition, since the conventional electric bicycle driving system drives the motor provided in the electric bicycle together in the crank phase angle section in which the occupant's power transmission efficiency is high, the total amount of energy consumed, which is the sum of the energy consumed by the occupant and the motor driving. Compared with this, there is a problem in that energy efficiency of the entire system is lowered.

In addition, since electric bicycles use the power of the human power and the power of the driver at the same time, it can be regarded as a hybrid system. Examples of the hybrid system are the power of human power, such as electric wheelchairs and electric scooters, in addition to the electric bicycle. An example is a system that uses the power of a driver simultaneously.

Hereinafter, a system that uses both human power and driver power, such as electric bicycles, electric wheelchairs, and electric scooters, is referred to as a hybrid system.

In addition, the speed sensor-based power assist device used in the conventional electric bicycle is an on-off method of detecting only whether the driver rolls a pedal. When a voltage is detected by the speed sensor, the torque value of the electric motor of the electric bicycle is detected. Set to maximum to assist with power.

However, since the existing electric bicycle assists the power in proportion to the RPM of the crankshaft measured from the Hall sensor, the power of the motor is rapidly reduced at low speed, when there is a problem that large power assistance is impossible when large power is required at low speed.

An alternative to the problem of the speed sensor method is a torque sensor method.

Torque sensor methods are mechanical methods for measuring the distortion of discs or springs that occur during pedaling, and have high mounting costs and difficult installation in conventional electric bicycles. An effective solution to control is needed.

Patent document 1 (Korean Patent Publication No. 10-2014-0142117) proposed an electric bicycle torque control device that can control the torque of the motor variably according to the analog output signal of the speed sensor. The motor output control is proportional to the speed, which is convenient. However, the digital speed sensor, which consists of a double Hall sensor, outputs a digital pulse signal. There was a problem that was difficult to use the speed sensor.

In addition, since the output of the motor is controlled in proportion to the pedaling speed, in order for the electric bicycle to run at high speed, the pedaling speed should be increased even if the electric bicycle driver does not want it. There was this.

The embodiment provides a power assist drive system and method using a virtual stroke drive of a hybrid system that can increase the energy efficiency by driving the motor in a low section rather than a section of high human power transmission efficiency.

In addition, the present invention provides a power assist drive system and method using a virtual stroke drive of the hybrid system to reduce the amount of torque change of the rotating shaft according to the force transmission of the hybrid system to enable smooth acceleration of the hybrid system.

The embodiment aims to increase the driving energy efficiency of the electric bicycle, reduce the pedaling heterogeneity and improve the riding comfort by driving the motor of the electric bicycle in proportion to the rigidity of the crank interacting with the person.

The problem to be solved by the present invention is not limited to the above-mentioned problem and other problems not mentioned herein will be clearly understood by those skilled in the art from the following description.

The present invention measuring unit for measuring the operating state of the crank; A controller configured to determine pre-cancer or current required for power assistance based on the measured value of the measurement unit; A motor unit to which the voltage or current is applied to provide a driving force; And a power supply unit providing power to components other than itself.

In one embodiment of the present invention, the measuring unit may be characterized by measuring the angle of the crank and the torque of the crank provided in the hybrid system.

The method may further include: initializing the measuring unit and starting a virtual stroke driving method waiting for power to be transmitted; An operation determining step of the virtual stroke driving method for determining whether the virtual stroke driving method is operated based on whether power is transmitted; Measuring the crank angle and the crank torque of the virtual stroke driving method; A storage step of the virtual stroke driving method in which the crank angle and the crank torque are stored in a storage unit; Determining a virtual stroke driving method for determining a voltage or a current to be applied to a virtual stroke driving motor by using the crank angle and the crank torque measured in the measuring step; And a virtual stroke driving method applying step of applying the determined voltage or current to the virtual stroke driving motor.

According to another embodiment of the present invention, the control unit may determine the voltage or current value based on the stiffness of the crank.

In addition, a crank stiffness-based power assist drive method comprising: a measurement preparation step of preparing a measurement by initializing a sensor; An operation detecting step of detecting whether the auxiliary driving method is operated; Obtaining an output value from the sensor; A crank stiffness calculation step of calculating the crank stiffness from the output value; A voltage or current determination step of determining a voltage or current to be applied to the motor in proportion to the crank stiffness; And applying the determined voltage or current to the motor.

According to the embodiment, there is an effect that can improve the energy efficiency of the hybrid system.

In addition, the wheel torque change amount according to the crank angle of the hybrid system is reduced.

In addition, smooth acceleration and ride comfort improvement of the hybrid system are possible.

According to another embodiment of the present invention, it is possible to accurately predict the intention of the occupant to drive the motor, to lower the pedaling heterogeneity, and to improve the riding comfort and energy efficiency.

In addition, while minimizing the heterogeneity of the pedaling, by increasing the energy efficiency has the advantage of light weight while obtaining the same output.

Various and advantageous advantages and effects of the present invention are not limited to the above description, and will be more readily understood in the course of describing specific embodiments of the present invention.

1 is a configuration diagram showing the configuration of a power assist drive system,

FIG. 2 is a diagram illustrating a measurement unit measuring torque from a power transmission unit of the configuration of FIG. 1 in a hybrid system according to an exemplary embodiment of the present disclosure.

3 is a diagram illustrating power compensation according to phase delay in the configuration of FIG. 1;

4 is a flowchart illustrating a processing flow of a power assist driving method using a virtual stroke driving of a hybrid system according to an embodiment of the present invention;

5 is a flowchart showing a processing procedure of FIG. 4;

6 is a graph showing the degree of the total force according to the crank angle when applying an embodiment of the present invention,

7 is a graph showing a change in the total torque according to the crank angle when applying the embodiment of the present invention.

8 is a graph showing the total power consumption according to the crank angle in the conventional power assist system,

9 is a graph showing the total power consumption according to the crank angle when applying another embodiment of the present invention,

10 is a flowchart illustrating a processing flow of a crank stiffness based power assist driving method according to another embodiment of the present invention;

FIG. 11 is a flowchart showing a processing procedure of FIG. 10.

As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in the drawings. However, this is not intended to limit the embodiments of the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the embodiments.

Terms including ordinal numbers such as first and second may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the embodiments, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of example embodiments. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

In the description of the embodiment, when one element is described as being formed "on or under" of another element, it is on (up) or down (on). or under) includes both two elements being directly contacted with each other or one or more other elements are formed indirectly between the two elements. In addition, when expressed as "on" or "under", it may include the meaning of the downward direction as well as the upward direction based on one element.

Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

1 to 11 clearly illustrate only the main features in order to conceptually clearly understand the present invention, and as a result, various modifications of the drawings are expected, and the scope of the present invention is limited by the specific shapes shown in the drawings. It doesn't have to be.

The present invention is a measuring unit for measuring the operating state of the crank, a control unit for determining a voltage or current required for power assistance based on the measured value of the measurement unit, a control unit for applying a voltage or current to provide a driving force, the voltage determined by the control unit or And a motor unit to which electric current is applied to provide driving power, and a power supply unit to supply electric power to components other than itself.

Hereinafter, the invention will be described according to the examples.

A power assist drive system and method using a virtual stroke drive of a hybrid system according to an embodiment of the present invention will be described with reference to FIGS. 1 to 7.

1 is a block diagram showing the configuration of a power assist drive system using a virtual stroke drive of a hybrid system.

Referring to FIG. 1, the power assist drive system 100 using the virtual stroke driving of a hybrid system according to an exemplary embodiment of the present invention may include a control unit 10, a motor unit 20, a storage unit 30, and a measurement unit 40. ) And the power supply unit 50.

The controller 10 controls the driving of the entire power assist drive system 100 using the virtual stroke drive of the hybrid system. Specifically, it serves to control the motor unit 20, the storage unit 30, and the measuring unit 40, which are components of the present invention. The controller 10 controls the measurement unit 40 to initialize the measurement unit 40, or receives the measurement values measured by the measurement unit 40, and when the virtual stroke generation timing and the virtual stroke are generated therefrom, The voltage or current to be applied to the motor is calculated, and the calculated voltage or current is applied to the motor of the hybrid system.

The controller 10 may also be implemented in the form of a conventional microprocessor.

When the power assist drive system 100 using the virtual stroke driving of the hybrid system is implemented as an electric bicycle, the control unit 10 virtualizes the body size and driving conditions of the occupant in order to reduce a sudden change in torque applied to the crank. The voltage or current required for the stroke drive can be determined. The driving situation may be determined in consideration of the degree of inclination of the road and the current acceleration degree. In order to take into account such driving conditions, control variables according to driving conditions may be stored in the storage unit 30, and the controller 10 may use a control variable stored in the storage unit 30 to supply a voltage or a current required for driving the virtual stroke. Can be determined.

The motor unit 20 may transmit a driving force for driving the power assist drive system using the virtual stroke driving of the hybrid system by a voltage or a current applied at the timing of the virtual stroke generation under the control of the controller 10. In addition, although the encoder may be provided in the motor unit 20, whether or not the encoder of the motor unit 20 is provided is not related to the configuration of the present invention, and the use of the encoder of the motor unit 20 is a known part. No explanation is given for this.

The storage unit 30 serves to store the torque of the crank according to the angle of the crank obtained from the measuring unit 40, and the angle and torque of the stored crank can be referred to by the controller 10.

The storage unit 30 may store an appropriate range or optimum value of the crank torque according to the angle of the crank in the form of a lookup table, and may be implemented to be referred to by the controller 10 as needed.

In one embodiment, when the crank rotates, the storage unit 30 may store the crank torque according to the angle of the crank measured from the measuring unit 40 in the storage table. At this time, since the crank rotates repeatedly, the crank torque according to the crank angle can be continuously updated, the control unit 10 can use the information continuously updated.

In addition, in a preferred embodiment of the present invention, the storage unit 30 may be implemented integrated into the control unit 10.

The measuring unit 40 measures an operating state of the crank provided in the hybrid system.

The measuring unit 40 may measure various variables capable of determining the rotation state of the crank, and various measuring apparatuses for measuring the same may be used. In one embodiment, the measurement unit 40 may measure the angle of the crank and the torque of the crank. The measuring unit 40 may be provided to measure the angle and torque of the crank respectively or together. The measurement unit 40 may use at least one of a crank torque sensor, a pedal force sensor, or a pressure sensor to measure the crank angle and torque.

If a crank torque sensor is used, the crank torque sensor may be installed in the frame or crank of the hybrid system. In one embodiment, when the crank torque sensor is installed in the frame, it can be installed at one point where the crank passes by while the crank is rotating. This is to improve the accuracy of the measured value of the torque is installed inside the rotation radius of the crank.

The power supply unit 50 serves to supply power to the control unit 10, the motor unit 20, and the measurement unit 40. When the storage unit 30 is implemented separately without being integrated into the control unit 10, the storage unit 30 is also implemented in the form of supplying power.

In addition, although the control unit 10 does not send a control signal to the power supply unit 50 in FIG. 1, the control unit 10 transmits a control signal to the power supply unit 50 so as to control the power supplied to each unit. May be

Referring to the lines connecting each part in Figure 1, the lines not shown at one end is a power line, it represents a line for supplying power generated by the power supply unit 50 to each part, the line with an arrow at one end Lines indicating a transmission direction of a control signal or a data transmission direction, indicating that signals or data are transmitted from a component connected to an end without an arrow to a component connected to an arrow with an end of the line.

In addition, in the above description of the present invention, for convenience of description, a case where the virtual stroke driving system is applied to a bicycle is expressed as an example, but this is to limit the virtual stroke driving system of the present invention to be applied only to a bicycle. It is to be understood that only the bicycle is illustrated as an example so that anyone, including those of ordinary skill in the art, may easily understand the present invention.

When the virtual stroke drive system of the present invention is applied to a wheelchair, in the description of the embodiment applied to the bicycle, it is understood that the crank is replaced by a rotating shaft and the pedal by a rim.

In addition, when the virtual stroke driving system of the present invention is applied to a device other than a bicycle or a wheelchair, the parts described as cranks or pedals in the description of the embodiments of the present invention correspond to the cranks or pedals of the corresponding devices. It will be understood by substituting the names of the components.

2 is a view showing that the measurement unit 40 measures the torque from the power transmission unit 60 in the power assist drive system using the virtual stroke driving of the hybrid system according to an embodiment of the present invention.

Referring to FIG. 2, the measurement unit 40 of the power assist drive system using the virtual stroke driving of the hybrid system may measure the torque acting on the crank from the force acting on the power transmission unit 60. The measurement unit 40 may be located inside the power transmission unit 60, and when separately positioned, may receive a force measured by the power transmission unit 60 using short-range communication. In addition, the power transmission unit 60 itself may operate as the measurement unit 40. In one embodiment, the power transmission unit 60 may be a pedal in the electric bike.

The power transmission unit 60 is connected to the end of the crank so as to be rotatable, and a load is applied for driving the power assist drive system 100 using the virtual stroke driving of the hybrid system. The power transmission unit 60 may measure the load applied to the power transmission unit 60 and the rotation angle θ formed by the power transmission unit 60 with the horizontal plane. The measurement unit 40 measures the total force F acting on the power transmission unit 60 using the load values (vertical component and horizontal component) and rotation angle θ measured by the power transmission unit 60. Thereafter, the measurement unit 40 separates the total force F acting on the power transmission unit 60 into the tangential component F _t and the normal component force F _n of the crank rotation radius. The measuring unit 40 may measure torque acting on the crank by using the tangential component F _t and the normal component component F _n .

1 and 2, the detailed operation of the power assist drive system using the virtual stroke drive of the hybrid system will be described.

The power assist drive system using the virtual stroke driving of the hybrid system measures the operating state of the crank from the measuring unit 40, and the control unit 10 based on the measured value of the measuring unit 40, the voltage required for the virtual stroke driving. Alternatively, the current is determined to drive the motor unit 20.

[Equation 1]

Equation 1 is an equation for obtaining a voltage or current value to be applied to the motor from the controller 10.

S _motor is a voltage or current signal to be applied to the motor,

k is a proportional constant and is set to minimize the amount of wheel torque change, and is set to 1 in the virtual stroke driving system according to the preferred embodiment of the present invention. Also, k may be adjusted to a value other than 1 in consideration of the driving situation and the like so as to minimize the amount of wheel torque change. According to an embodiment, the k values according to various situations and respective situations may be previously stored as a lookup table and stored in the storage unit 30, and the controller 10 may select the necessary values and apply them to the calculation. have.

Denotes the angle of the current crank measured by the measuring unit 40.

Is the phase delay angle, which is the difference between the crank angle at the time when the driving force is provided by the occupant and the crank angle at the time when the driving force is provided by the virtual stroke driving, and is a preset value, but the change is made to minimize energy consumption during driving. It is possible. In one embodiment, the phase delay angle in four-stroke crank drive may be used at 45 degrees.

Also,

If the value is 360 degrees, the timing at which the driving force provided by the virtual stroke driving is provided and the timing at which the driving force is provided by the occupant become the same, so that the meaning of using the virtual stroke driving method is lost. You do not need to generate

You can also set the value to 360 degrees.

3 is a diagram illustrating power compensation according to phase delay in a power assist drive system using a virtual stroke drive of a hybrid system according to an exemplary embodiment of the present invention.

In FIG. 3, a human, electric bicycle (PAS), and virtual stroke driving system (VSA) are separately shown as graphs showing degrees of torque according to phases.

In the case of humans, when the bicycle is driven, torque is generated according to the angle of the crank and the direction in which the load is applied. In addition, in the case of the electric bicycle, the assistance of the power occurs, but this serves only to increase the power, it can be seen that the delay of the phase angle does not occur.

However, in the power assist drive system using the virtual stroke drive of the hybrid system, the human and the motor unit work together. This is not a simple assistance of power as in the case of electric bicycles, but the phase delay is applied to the crank torque to apply motor power.

As shown in Equation 1, the efficiency of power assistance may be improved by using a phase delay angle.

As such, the virtual stroke driving system of the hybrid system has an effect of increasing driving efficiency by assisting power in an area where human driving force is hard to operate by using delayed power assistance.

On the other hand, with reference to the accompanying drawings will be described a power assist drive method using a virtual stroke drive of a hybrid system according to an embodiment of the present invention. However, the same descriptions as those described in the power assist driving system using the virtual stroke driving of the hybrid system according to the exemplary embodiment will be omitted.

4 is a flowchart illustrating a processing flow of the power assist drive method using the virtual stroke drive of the hybrid system according to an embodiment of the present invention, Figure 5 is a flow chart of the processing procedure of the power assist drive method using the virtual stroke drive of the hybrid system. It is a flowchart showing. 4 and 5, the same reference numerals as used in FIGS. 1 to 3 denote the same members and detailed descriptions thereof will be omitted.

Referring to FIG. 4, the flow of a schematic process of the power assist driving method using the virtual stroke driving of the hybrid system according to another embodiment of the present invention may be divided into five steps of F1000 to F1400.

Hereinafter, five steps of F1000 to F1400 will be described step by step.

The step F1000 is a step of starting the power assist driving method using the virtual stroke driving of the hybrid system according to the present invention. When a person rides in the hybrid system according to the present invention, the passenger's pedal input, that is, a state of waiting for pedaling do.

In step F1100, when the crank and the wheel starts to rotate due to the pedaling of the person in the hybrid system according to the present invention, the measurement unit 40 starts the measurement and starts to output the measured value.

In operation F1200, the measurement value output of the measurement unit 40 is stored in the storage unit 30 via the control unit 10. Here, the measured value includes the angle and torque of the crank, and when the angle and torque of the crank are stored in the storage unit 30, torques according to various angles are stored in association with the angle.

In step F1300, the crank torque associated with the crank angle after the preset crank angle (= after the phase delay angle) is multiplied by an appropriate gain or proportional constant k to determine the voltage or current to be applied to the motor.

In step F1400, the motor is driven in a virtual stroke by applying the voltage or current determined in step F1300 to the motor.

The power assist drive method using the virtual stroke drive of the hybrid system according to the present invention, after applying the voltage or current to the motor through the above steps, and returns to step F1100, while the pedaling of the occupant as described above By repeatedly performing the steps F1100 to F1400, the motor of the hybrid system is driven in a virtual stroke.

Referring to FIG. 5, FIG. 5 is a flowchart configured to reflect a case in which a passenger arbitrarily turns on / off a power assist drive system 100 and a method using a virtual stroke drive of a hybrid system in the process flow of FIG. 4. .

Referring to the processing of the power assist drive method using the virtual stroke drive of the hybrid system as follows.

Step S1000 is a step of starting the power assist driving method using the virtual stroke driving of the hybrid system according to an embodiment of the present invention, when a person rides on the hybrid system according to the present invention, the measurement unit 40 automatically To initialize the state, the state of waiting for the drive of the power transmission unit 60, that is, a state of waiting for the transmission of power.

Hereinafter, step S1000 is referred to as a start step of the virtual stroke driving method.

In step S1100, it is determined whether the person in the hybrid system according to an embodiment of the present invention, the virtual administrative driving method.

If the virtual stroke driving method is not operated, the process returns to step S1000.

When the virtual stroke driving method is operated, the measurement value output including the angle and torque of the crank output from the measurement unit 40 is transmitted to the control unit 10.

In addition, as a means for the passenger to operate the virtual stroke driving method according to the present invention, when the physical switch is provided in the hybrid system, when the display of the touch panel is provided in the hybrid system, or in conjunction with the passenger's smartphone The case where the control unit 10 is provided in the hybrid system may be used. All of these means are well known, and since they are obvious to everyone in the general public, detailed description thereof will be omitted.

Hereinafter, operation S1100 is referred to as an operation determination stage of the virtual stroke driving method.

In step S1200, the measured value including the angle and torque of the crank is transmitted from the measuring unit 40 to the control unit 10, and in the subsequent step, the control unit 10 determines the voltage or current using the received measured value In addition, the controller 10 transmits the measured value to the storage unit 30.

Here, the measurement value is an example of the angle and torque of the crank, but is not limited to this, various measurement values for knowing the operating state of the crank provided in the hybrid system can be used.

In addition, the sensor included in the measurement unit 40 is a crank torque sensor or a pedal force sensor, and measures or predicts the crank torque, measures or predicts the crank angle from the encoder or the tilt sensor, and outputs these measured values together with the control unit. To (10). The control unit 10 measures the current operating state of the crank and at the same time compares the previous driving state to predict the operating state of the next crank.

The measurement unit 40 refers to a crank torque sensor or a pedal force sensor, a pressure sensor, an encoder, an inclination sensor, etc., and measures any one of a plurality of sensors provided by the measurement unit 40 in the hybrid system. Note that no reference is made specifically.

Hereinafter, step S1200 is referred to as a measurement step of the virtual stroke driving method.

In operation S1250, the storage unit 30 stores the received measured values. In one embodiment, the storage unit 30 separately stores the crank angle and the crank torque among the received measured values.

Here, storing the measured values separately in the storage unit 30 does not mean that the crank angle and the crank torque are simply divided and stored as separate values, and the crank angle and the crank torque at the angle are related. It means that it is stored.

As such, by being stored in association with the individual crank angle and the crank torque, it is possible to grasp the tendency of the crank torque to change according to the crank angle in some cases.

In one embodiment, the crank angle and the crank torque measured by the measuring unit 40 are sequentially stored in the storage table provided in the storage unit 30, the crank angle and crank torque newly measured during the virtual stroke driving is stored in the storage table Can be updated continuously. This is to determine the voltage or current to be applied to the motor by reflecting this, because the rotation speed of the crank is different every revolution. The shape of the storage table is not limited and can be stored in various ways, such as the shape of a continuous graph or the shape of a digitized table.

Hereinafter, step S1250 is referred to as a storage step of the virtual stroke driving method.

In step S1300, the control unit 10 determines the voltage or current to be applied to the motor through the following operation, it is formulated as follows. Equation 2 is a voltage or current applied to the motor is determined in the same manner as the power assist drive system using the virtual stroke drive of the hybrid system.

[Equation 2]

Equation 2 is an equation for obtaining a voltage or current value to be applied to the motor from the controller 10.

S _motor is a voltage or current signal to be applied to the motor,

Denotes the angle of the current crank measured by the measuring unit 40.

Also,

You can also set the value to 360 degrees.

The current or voltage value calculated by Equation 2 above is

1) obtain the previous crank angle obtained by subtracting the preset angle from the current crank angle included in the sensor's measurement value,

2) refer to the crank torque associated with the crank angle of 1) above,

3) The voltage or current to be applied to the motor is determined by multiplying the crank torque of 2) by an appropriate gain or proportional constant k.

Here, the gain or proportional constant k is determined such that the rate of change of the wheel torque of the electric bicycle is minimized.

In addition, according to the exemplary embodiment, a method of forming a look-up table and storing the values of some suitable proportional constant k in advance in the storage unit 30 and selecting and applying the appropriate values by referring to the control unit 10 may be possible. Do.

In addition, the k value may be determined in consideration of driving conditions of the hybrid system.

In one embodiment, the k value may consider whether the road is inclined while driving. When the hybrid system is driving uphill, the weight of k may be added, and when driving downhill, the k value may be lowered for stable driving in an acceleration situation. In this way, the k value may be stored in the storage unit 30 in advance by using a relationship between the inclination angle of the road and the driving speed.

The control unit 10 determines the power and voltage required for power assistance by using the measured value of the measuring unit 40 measuring the operating state of the crank, and at this time, to allow more comfortable driving in consideration of the variable according to the driving situation. do.

Hereinafter, step S1300 will be referred to as a determination step of the virtual stroke driving method.

In operation S1400, the motor is driven in a virtual stroke by applying the voltage or current determined in operation S1300 to the motor.

Hereinafter, step S1400 is referred to as an application step of the virtual stroke driving method.

As such, the power assist driving method using the virtual stroke driving of the hybrid system according to the embodiment of the present invention can reduce the amount of torque change by supplementing the driving force of the hybrid system while repeatedly performing the steps of S1000 to S1400, thereby smooth acceleration. Can improve ride comfort.

6 is a graph showing the degree of the total force according to the crank angle, when applying the embodiment of the present invention, Figure 7 is a graph showing the change of the overall torque according to the crank angle, when applying the embodiment of the present invention to be.

6 and 7, in the case of using the power assist drive system 100 and the method using the virtual stroke driving of the hybrid system according to the embodiment of the present invention, the amount of torque change according to the crank angle can be confirmed.

6 and 7 show the change in total power and crank angle according to the crank angle of the electric bicycle to which the human bicycle, the electric bicycle (PAS) and the virtual stroke driving system or method (VSA) are applied. The amount of change in torque is shown.

The experiment shows the total power and torque required to achieve the same speed. Looking at the graph, it can be seen that in the case of an electric bicycle, the crank torque is reduced, but the total power is increased rather than a general bicycle.

However, in the case of the electric bicycle to which the virtual stroke driving is applied, it can be seen that both the total power and the torque of the crank are effectively reduced, which can be confirmed that more efficient power assistance is achieved when the virtual stroke driving is applied.

1 and 8 to 11, a power assist drive system and method based on crank stiffness according to another embodiment of the present invention will be described.

Referring to FIG. 1, the power assist drive system 100 based on the crank stiffness according to the embodiment of the present invention includes a control unit 10, a motor unit 20, a storage unit 30, a measurement unit 40, and a power supply unit ( 50).

The controller 10 controls the driving of the entire power assist drive system 100 based on the crank stiffness. Specifically, it serves to control the motor unit 20, the storage unit 30, and the measuring unit 40, which are components of the present invention. The control unit 10 controls the measurement unit 40 to initialize the measurement unit 40 or receives the measurement values measured by the measurement unit 40, and measures the generation timing of the power assist driving system based on the measurement unit 40. When power assistance occurs, the voltage or current required for power assistance is calculated, and the calculated voltage or current is determined based on the crank stiffness and applied to the motor.

When the power assist drive system 100 based on the crank stiffness is implemented as an electric bicycle, the control unit 10 adjusts the crank stiffness based power assist in accordance with the passenger's body size and driving conditions to reduce the sudden change in torque applied to the crank. Determine the voltage or current required for The driving situation may be determined in consideration of the degree of inclination of the road and the current acceleration degree. In order to take into account such driving conditions, control variables according to driving conditions may be stored in the storage unit 30, and the controller 10 may use a control variable stored in the storage unit 30 to supply a voltage or a current required for power assist driving. Can be determined.

The motor unit 20 may provide a driving force for driving the power assist drive system based on the crank stiffness by a voltage or a current applied to the timing of generating the power assist under the control of the controller 10. In addition, although the encoder may be provided in the motor unit 20, whether or not the encoder of the motor unit 20 is provided is not related to the configuration of the present invention, and the use of the encoder of the motor unit 20 is a known part. No explanation is given for this.

The measuring unit 40 may measure various variables capable of determining the rotation state of the crank, and various measuring apparatuses for measuring the same may be used. In one embodiment, the measurement unit 40 may measure the angle of the crank and the torque of the crank. The measuring unit 40 may be provided to measure the angle and torque of the crank respectively or together. The measurement unit 40 may use at least one of an encoder, a crank torque sensor, a pedal force sensor, or a pressure sensor to measure the crank angle and torque.

The power supply unit 50 may provide power to components other than itself. The power supply unit 50 serves to supply power to the control unit 10, the motor unit 20, and the measurement unit 40. When the storage unit 30 is implemented separately without being integrated into the control unit 10, the storage unit 30 is also implemented in the form of supplying power.

In addition, in the description of the present invention, for convenience of description, a case in which the crank rigidity-based power assist system is applied to the bicycle has been expressed as an example, which means that the crank stiffness-based power assist system of the present invention may be applied only to the bicycle. It is not intended to be limiting, but it is to be understood that the bicycle is exemplified only by others, including those of ordinary skill in the art.

When the crank stiffness-based power assistance system of the present invention is applied to a wheelchair, in the description of the embodiment applied to the bicycle, it is understood that the crank is replaced by the rotational axis and the pedal by the rim.

In addition, when the crank stiffness-based power assistance system of the present invention is applied to a device other than a bicycle or a wheelchair, the parts described as cranks or pedals in the description of the embodiments of the present invention may be applied to the cranks or pedals of the corresponding devices. It will be understood by substituting the names of the corresponding components.

Referring to Figure 1, the detailed operation of the power assist drive system based on the crank stiffness according to another embodiment of the present invention will be described.

The power assist drive system based on the crank stiffness measures the operation state of the crank by the measurement unit 40, and the control unit 10 measures the voltage or current required for the power assist drive based on the measured value of the measurement unit 40. The motor unit 20 is driven by the determination.

The value of the voltage or current determined by the controller 10 is determined based on the stiffness of the crank. In one embodiment, the voltage or current value is proportional to the amount of change in the crank torque, and may be determined to be inversely proportional to the amount of change in the crank angle or the rotational speed of the crank.

[Equation 3]

only,

Current crank angle

Crank stiffness at.

(Equation 3 above

Is the voltage or current to be applied to the motor,

Is a proportional constant, a value set to reduce a sudden change in torque (changeable during driving),

Is the stiffness of the crank,

Is,

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)

According to Equation 3, the controller 10 determines the voltage or current value based on the rigidity acting on the crank. As shown in Equation 3, the supply power is determined based on the absolute value of the stiffness to supply voltage or current only when the crank is advanced.

In another embodiment, the controller 10 may determine a voltage or current value for power assistance by Equation 4 below.

[Equation 4]

only,

Current crank angle

Crank stiffness at.

(Equation 4 above

Is the voltage or current to be applied to the motor,

Is the stiffness of the crank,

Is,

Is the phase delay angle, which is a variable for reducing the energy consumed for driving (variable during driving),

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)

Equation 4 determines the value of the voltage or current to be applied to the motor in consideration of the phase delay angle to the stiffness value determined by the controller 10. The controller 10 may determine the driving intention of the occupant from the stiffness of the crank, reduce the heterogeneity by assisting the power at an appropriate time using the phase delay angle, and increase energy efficiency by removing unnecessary force for driving.

The k values used in the equations (3) and (4) may vary depending on the torque change amount of the crank. As an example, when the torque change amount has a positive change amount, the driver's driving will is determined to be high and the k value may be increased. When the torque change amount has a negative change amount, the driver's driving will is determined to be low and k is determined. You can decrease the value.

In addition, the k value is a proportional constant, which is set to reduce the sudden change in torque, and can be changed in accordance with a situation that changes during driving.

8 is a graph showing the total power consumption according to the crank angle in the conventional power assist system, Figure 9 is a graph showing the total power consumption according to the crank angle when applying an embodiment of the present invention. 8 and 9 were tested under the same load and traveling speed, and the power assist drive system based on the crank stiffness can be typically applied to an electric bicycle.

FIG. 8 illustrates a case in which a conventional power assist system assists power using a general PAS mode, in which driving of a pedal and power assist of a motor occur at the same cycle.

9 is a case of applying a power assist drive system based on crank stiffness, which is another embodiment of the present invention, there is a difference in a phase in which a peak value appears between a drive of a motor and a drive of a pedal, and a phase shift occurs at an angle. You can check it.

In addition, in FIG. 9, the power assist drive system does not continuously operate, but assists power at the time when the occupant generates power through pedaling, and decreases the power assist power at some point (before reaching the maximum value). can confirm.

Comparing FIG. 8 with FIG. 9, in the case of the PAS, the average of the total power is 136.8 W, but in another embodiment of the present invention, it can be seen that the average of the total power corresponds to 114 W. It can be seen that the decrease. This can be seen that the energy efficiency is increased by reducing the unnecessary energy consumption caused by the heterogeneity between the occupant and the pedal for transmitting power.

On the other hand, with reference to the accompanying drawings will be described a power assist drive method based on crank stiffness according to another embodiment of the present invention. However, the same description as that described in the power assist driving system based on the crank stiffness according to another embodiment of the present invention will be omitted.

FIG. 10 is a flowchart illustrating a processing flow of a crank stiffness based power assist driving method according to an embodiment of the present invention, and FIG. 11 is a flowchart illustrating a processing sequence of a crank stiffness based power assist driving method. 10 and 11, the same reference numerals as used in FIGS. 1 and 8 to 9 denote the same members, and detailed descriptions thereof will be omitted.

Referring to Figure 10, according to another embodiment of the present invention, the flow of the rough processing process of the power assist drive method based on the crank stiffness may be divided into six steps of F2000 to F2500.

Hereinafter, six steps of F2000 to F2500 will be described step by step. As described above, the present invention will be described based on the electric bicycle which is a representative embodiment.

In step F2000, the crank stiffness-based pedal assist driving method according to the present invention is started. When a person rides in the electric bicycle according to the present invention, the passenger's pedal input, that is, a state of waiting for pedaling, is entered.

In step F2100, when the crank starts to rotate due to the pedaling of the person in the electric bicycle according to the present invention, the sensor (s) starts the measurement and starts to output the measured value.

In step F2200, the torque and angle of the crank is obtained from the output of the crank torque sensor.

In step F2300, the amount of crank torque change per unit time obtained from the crank torque and crank angle value obtained in step F2200 is divided by the amount of crank angle change per unit time, and the absolute value is taken to obtain crank stiffness.

In step F2400, the crank stiffness obtained in step F2300 is multiplied by the phase delay angle φ d, and multiplied by the proportional constant k at a later crank angle position to determine the voltage or current to be applied to the motor. In other words, the signal of the motor applied at the current crank angle is actually multiplied by the gain k by the crank stiffness obtained from the previous crank angle by φ.

In step F2500, the voltage or current to be applied to the motor, which is determined in step F2400, is applied to the motor.

Crank stiffness-based pedal auxiliary drive method of the electric bicycle according to the present invention, after applying the voltage or current to the motor through the above steps, and returns to step F2100, while the pedaling of the occupant as described above F2100 to By repeatedly performing the F2500 steps, the motor of the electric bicycle is driven to reflect the change in the crank stiffness.

11 is a flowchart showing a processing procedure of a power assist drive method based on crank stiffness.

FIG. 11 is a flowchart configured to reflect a case where an occupant arbitrarily turns on / off a crank stiffness-based pedal assist driving method in the processing flow of FIG. 10.

Referring to FIG. 11, a process of a crank stiffness-based pedal assist driving method of an electric bicycle according to an exemplary embodiment of the present invention will be described below.

Hereinafter, six steps of S2000 to S2500 will be described in detail step by step.

Step S2000 is a step in which the crank stiffness-based pedal assist driving method according to the present invention is started. When a person rides in the electric bicycle according to the present invention, the output value of the sensor (s) is automatically initialized and the pedal input of the passenger is performed. Waiting, that is, waiting for pedaling.

In step S2100, it is determined whether the person riding in the electric bicycle according to the present invention has activated the crank rigidity-based pedal assist drive method, and if it is not operated, returns to step S2000, and if it is operated, the crank rotates due to pedaling. Once started, the sensor (s) initiate the measurement and output the measurement.

In step S2200, the torque and angle of the crank is obtained from the output of the sensor installed in the frame or crank of the electric bicycle according to the present invention.

In one embodiment, the sensor may measure torque of the crank using at least one of a crank torque sensor, a pedal force sensor or a pressure sensor, simultaneously measure the crank angle from an encoder or tilt sensor, and output both measurements together. have.

In step S2300, the amount of crank torque change per unit time obtained from the crank torque and crank angle value obtained in step S2200 is divided by the amount of crank angle change per unit time, and the absolute value is taken to obtain crank stiffness.

In the step S2400, a phase delay angle φ is given to the crank stiffness obtained in the step S2300, and multiplied by a proportional constant k at a subsequent crank angle position by φ to determine a voltage or a current to be applied to the motor. Is expressed.

In addition, a calculation process such as Equation 6 may be used to exclude the phase delay in operation S2400.

In step S2500, the voltage or current to be applied to the motor, determined in step S2400 is applied to the motor.

[Equation 5]

only,

Current crank angle

Crank stiffness at.

In Equation 5

Is the voltage or current to be applied to the motor,

Is a proportional constant, which is a value set to reduce a sudden change in torque (changeable during driving),

Is the stiffness of the crank,

Is,

Is the change in crank torque per unit time,

Denotes the amount of change in the crank angle per unit time.

According to Equation 5, the controller 10 determines the voltage or current value based on the rigidity acting on the crank. As shown in Equation 5, the supply power is determined based on the absolute value of the stiffness to supply voltage or current only when the crank is advanced.

In another embodiment, the controller 10 may determine a voltage or current value for power assistance by Equation 6 below.

[Equation 6]

only,

Current crank angle

Crank stiffness at.

(Equation 6 above

Is the voltage or current to be applied to the motor,

Is the stiffness of the crank,

Is,

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)

The embodiments of the present invention have been described in detail with reference to the accompanying drawings.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

[Description of the Code] 10: control unit, 20: motor unit, 30: storage unit, 40: measuring unit, 50: power supply unit, 60: power transmission unit

Claims

A measuring unit measuring an operating state of the crank;

A controller configured to determine a voltage or current required for power assist based on the measured value of the measurement unit;

A motor unit to which the voltage or current is applied to provide a driving force; And

A power supply unit providing power to components other than itself;

Power assist drive system comprising a.
According to claim 1,

The measuring unit is a power assist drive system, characterized in that for measuring the angle of the crank and the torque of the crank provided in the hybrid system.
The method of claim 2,

And the measuring unit uses at least one of a crank torque sensor, a pedal force sensor, and a pressure sensor.
The method of claim 3, wherein

The crank torque sensor is installed in the frame of the hybrid system or the crank drive system.
The method of claim 4, wherein

When the crank torque sensor is installed in the frame,

And the crank torque sensor is installed at one point of the portion where the crank passes while the crank rotates.
The method of claim 2,

Storage unit for storing the torque of the crank according to the angle of the crank

Auxiliary drive system further comprising.
The method of claim 2,

The control unit selects a control variable according to a driving situation to reduce a sudden change in torque applied to the crank, and determines the voltage or current required for driving the virtual stroke in consideration of the control variable. Driving system.
The method of claim 2,

The control unit,

Power assist drive system, characterized in that for determining the voltage or current to be applied to the motor through the following equation (1).

[Equation 1]

(In Equation 1,
Is the voltage or current to be applied to the motor,

Crank angle
Represents the crank torque for

Is a proportional constant and is set to reduce the sudden change in torque (changeable during driving).

Is the current crank angle,

Is the phase delay angle, which is a variable to increase energy efficiency (can be changed during driving)
The method of claim 2,

The crank is connected to the rotatable power transmission,

And the measuring unit measures the torque acting on the crank from the force acting on the power transmission unit.
The method of claim 9,

And the measuring unit converts vertical and horizontal components acting on the power transmission unit into tangential and normal components acting on the crank and calculates torque acting on the crank shaft.
Initializing the measurement unit and starting a virtual stroke driving method waiting for power to be transmitted;

An operation determining step of the virtual stroke driving method for determining whether the virtual stroke driving method is operated based on whether power is transmitted;

Measuring the crank angle and the crank torque of the virtual stroke driving method;

A storage step of the virtual stroke driving method in which the crank angle and the crank torque are stored in a storage unit;

Determining a virtual stroke driving method for determining a voltage or a current to be applied to a virtual stroke driving motor by using the crank angle and the crank torque measured in the measuring step; And

Applying a virtual stroke driving method for applying the determined voltage or current to a virtual stroke driving motor;

Power assist drive method comprising a.
The method of claim 11, wherein

In the measuring step of the virtual stroke driving method,

The voltage or current is a power assist drive method characterized in that determined in consideration of the passenger's body size and driving conditions.
The method of claim 12,

The driving situation is a power assist drive method, characterized in that considering the inclination angle of the road to run.
The method of claim 11, wherein

In the storing step of the virtual stroke driving method,

The crank angle and the crank torque are sequentially stored according to the rotation angle of the crank,

And a crank angle and a crank torque, which are newly measured when the virtual stroke is driven, are updated in the storage table.
The method of claim 12,

In the determining step of the virtual stroke driving method,

The voltage or current is a power assist drive method characterized in that for determining the voltage or current to be applied to the motor through the equation (2).

[Equation 2]

(In Equation 1,
Is the voltage or current to be applied to the motor,

Crank angle
Represents the crank torque for

Is a proportional constant and is set to reduce the sudden change in torque (changeable during driving).

Is the current crank angle,

Is the phase delay angle, which is a variable to increase energy efficiency (can be changed during driving)
According to claim 1,

And the control unit determines the voltage or current value based on the rigidity of the crank.
The method of claim 16,

And the measuring unit uses at least one of a crank torque sensor, a pedal force sensor, and a pressure sensor.
The method of claim 17,

The crank torque sensor is a power assist drive system installed in the frame or the crank.
The method of claim 18,

When the crank torque sensor is installed in the frame,

And the crank torque sensor is installed at one point of the portion where the crank passes while the crank rotates.
The method of claim 16,

The voltage or current value determined by the control unit is proportional to the amount of change in the crank torque, and is inversely proportional to the amount of change in the crank angle or the rotational speed of the crank.
The method of claim 16,

Storage unit for storing the torque of the crank according to the angle of the crank

Auxiliary drive system further comprising.
The method of claim 20,

The crank stiffness of the power assist drive system, characterized in that determined by the following equation (3).

[Equation 3]

only,
Current crank angle
Crank stiffness at.

(Equation 3 above
Is the voltage or current to be applied to the motor,

Is a proportional constant, a value set to reduce a sudden change in torque (changeable during driving),

Is the stiffness of the crank,
Is,

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)
The method of claim 20,

The crank stiffness is a power assist drive system characterized in that determined by the following equation (4).

[Equation 4]

only,
Current crank angle
Crank stiffness at.

(Equation 4 above
Is the voltage or current to be applied to the motor,

Is a proportional constant, a value set to reduce a sudden change in torque (changeable during driving),

Is the stiffness of the crank,
Is,

Is the phase delay angle, which is a variable for reducing the energy consumed for driving (variable during driving),

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)
Crank rigidity based power assist drive method,

A measurement preparation step of preparing a measurement by initializing the sensor;

An operation detecting step of detecting whether the auxiliary driving method is operated;

Obtaining an output value from the sensor;

A crank stiffness calculation step of calculating the crank stiffness from the output value;

A voltage or current determination step of determining a voltage or current to be applied to the motor in proportion to the crank stiffness;

Applying the determined voltage or current to a motor;

Power assist drive method comprising a.
The method of claim 24,

And wherein said calculating step calculates an absolute value of said crank stiffness.
The method of claim 24,

The crank stiffness calculation step and the step of determining the voltage or current, the power assist drive method, characterized in that for determining the crank stiffness and the voltage or current to be applied to the motor.

[Equation 5]

only,
Current crank angle
Crank stiffness at.

(Equation 5 above
Is the voltage or current to be applied to the motor,

Is a proportional constant, a value set to reduce a sudden change in torque (changeable during driving),

Is the stiffness of the crank,
Is,

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)
The method of claim 24,

The crank stiffness calculation step and the step of determining the voltage or current, the power assist drive method characterized in that for determining the crank stiffness and the voltage or current to be applied to the motor through the equation (6).

[Equation 6]

only,
Current crank angle
Crank stiffness at.

(Equation 6 above
Is the voltage or current to be applied to the motor,

Is a proportional constant, a value set to reduce a sudden change in torque (changeable during driving),

Is the stiffness of the crank,
Is,

Is the phase delay angle, which is a variable for reducing the energy consumed for driving (variable during driving),

Is the change in crank torque per unit time,

Is the amount of change in crank angle per unit time.)
The method of claim 26 or 27,

remind
Above
A power assist drive method characterized in that it changes in accordance with.
The method of claim 24,

In the operation detection step,

Determine whether the auxiliary driving method is activated;

If not activated, the process returns to the measurement preparation step,

In the case of operating the power assist drive method characterized in that the measured value is output from the sensor when the crank starts to rotate.
The method of claim 24,

The sensor measures the torque of the crank using at least one of a crank torque sensor, a pedal force sensor or a pressure sensor, simultaneously measures the crank angle from the encoder or the tilt sensor, and outputs the two measured values together. Secondary drive method.