WO2018006729A1

WO2018006729A1 - Wheel rotational speed detection apparatus and detection method

Info

Publication number: WO2018006729A1
Application number: PCT/CN2017/090436
Authority: WO
Inventors: 肖艳杰; 石永福; 陈映杰
Original assignee: 舍弗勒技术股份两合公司; 肖艳杰; 石永福; 陈映杰
Priority date: 2016-07-05
Filing date: 2017-06-28
Publication date: 2018-01-11
Also published as: CN107576811A

Abstract

A wheel rotational speed detection apparatus, where integrated in a wheel are: a wheel hub motor, an excitation unit (2), and a rotary transformer (1). The rotary transformer (1) receives an alternating excitation signal from the excitation unit (2) to monitor the rotational speed of the motor and generates an output signal comprising motor rotational speed information; the output signal is converted into a square wave signal, the square wave signal being an ABS input signal corresponding to the rotational speed of the wheel. Also provided is a wheel rotational speed detection method. The output signal of the rotary transformer (1) is utilized in conversion processing to detect the rotational speed of the wheel, thus replacing a conventional solution in which a wheel rotational speed sensor is utilized in detecting the rotational speed of the wheel. The wheel hub motor, the rotary transformer (1), and the excitation unit (2) are integrated in the wheel; a conversion unit (3) is an electronic component and has a small footprint. The wheel rotational speed detection apparatus obviates a wheel rotational speed sensor, obviates the need for additional external mechanical components, neither modifies the mechanical structure of the wheel, nor causes inconvenience with respect to the wheel structure and wheel layout.

Description

Wheel speed detecting device and detecting method

The present application claims priority to Chinese Patent Application No. 201610525008.9, entitled "Wheel Speed Detection Device and Detection Method", filed on July 5, 2016, the entire contents of which is incorporated herein by reference. .

Technical field

The invention relates to the technical field of a hub motor, and in particular to a wheel rotation speed detecting device and a detecting method for use in a hub motor.

Background technique

During the braking process of the car, the Antilock Brake System (ABS) determines whether the wheel tends to lock according to the wheel speed signal input by the wheel speed sensor, thereby making an anti-lock control signal.

At present, in the field of hub motor technology, a wheel speed sensor is mounted on a wheel, and a wheel speed sensor is used to test the wheel speed and send it to the ABS. The wheel speed sensor works on the principle that the wheel speed sensor comprises a magnetic coil and an inductive component. The magnetic ring gear is mounted on the wheel, the magnetic ring gear is coaxial with the wheel, and the number of teeth in the magnetic ring gear is w. In the radial direction of the magnetic ring gear, the sensing assembly is spaced from the magnetic ring gear. When the magnetic ring gear rotates with the wheel, the sensing component can sense a change in the magnetic field and generate a periodic sine wave corresponding to one tooth of the magnetic ring gear. When the wheel makes one revolution, w sine waves can be generated, so the wheel speed can correspond to the number of sine waves generated per unit time. After that, the sine wave is converted into a square wave and sent to the ABS. The ABS reads the number of high-level occurrences in each square wave signal generation period to determine whether the wheel tends to lock.

This square wave signal corresponding to the wheel speed has the following problem: the wheel speed sensor is an external mechanical component with respect to the wheel. Therefore, an additional adapter is required to secure the wheel speed sensor to the wheel, which affects the wheel structure and inconveniences in the layout of the components on the wheel.

Summary of the invention

The problem to be solved by the present invention is that in the field of the existing wheel motor technology, in the wheel speed detecting method, the wheel speed sensor is an external mechanical component with respect to the wheel, and an additional adapter is needed to fix the wheel speed sensor to the wheel, which affects the wheel structure and It is inconvenient for the layout of the components on the wheel.

In order to solve the above problems, the present invention provides a wheel rotation speed detecting device in which: an in-wheel motor, an excitation unit, and a resolver are integrated, the hub motor is coupled to the wheel to drive the wheel to rotate; and the resolver is connected The hub motor receives an alternating excitation signal from the excitation unit to monitor a motor speed to generate an output signal including motor speed information; the wheel speed detecting device is integrated in the wheel, and includes: a conversion unit, configured to: A square wave signal is generated according to the output signal, and the square wave signal is an ABS input signal corresponding to a wheel speed.

Optionally, the wheel rotation speed detecting device further includes: a demodulator, configured to receive the output signal and the alternating excitation signal, and demodulate an envelope signal corresponding to the motor speed; the conversion unit For receiving the envelope signal and converting into the square wave signal.

Optionally, the conversion unit includes: an operation unit, configured to receive the envelope signal and calculate a phase angle signal corresponding to a wheel rotation angle in the square wave signal generation period every time a square wave signal generation period is calculated; And a square wave generating unit configured to generate the square wave signal according to the phase angle signal in each of the square wave signal generation periods.

Optionally, the converting unit includes: an operating unit, configured to receive an envelope signal of the corresponding motor speed and calculate an envelope signal corresponding to the wheel speed; and a square wave generating unit configured to rotate the corresponding wheel The envelope signal is converted to the square wave signal.

Optionally, the arithmetic unit and the square wave generating unit are integrated.

Optionally, the demodulator, the conversion unit and the excitation unit are integrated in the same housing.

Optionally, the excitation unit is further configured to: receive an output signal of the resolver and demodulate a motor speed signal; and the converting unit is configured to: receive the motor speed signal and convert the signal into the square wave signal.

The invention also provides a wheel rotation speed detecting method, which integrates: an in-wheel motor, an excitation unit and a rotary transformer, wherein the hub motor is connected to the wheel to drive the wheel to rotate; the rotary transformer is connected to the hub motor And for receiving an alternating excitation signal from the excitation unit to monitor a motor speed to generate an output signal including motor speed information; the wheel speed detecting method includes: converting the output signal into a square wave signal, the square wave The signal is the ABS input signal corresponding to the wheel speed.

Optionally, the method for converting the output signal into a square wave signal comprises: demodulating an envelope signal corresponding to a motor speed by using the output signal and the alternating excitation signal; converting the envelope signal into a Square wave signal.

Optionally, the method for converting the envelope signal into the square wave signal comprises: calculating, according to the envelope signal, a wheel rotation angle in a square wave signal generation period every time a square wave signal generation period is calculated Corresponding phase angle signal; generating the square wave signal according to the phase angle signal in each square wave signal generation period.

Optionally, the method for converting the envelope signal into the square wave signal comprises: receiving an envelope signal of the corresponding motor speed and calculating an envelope signal corresponding to the wheel speed; and the packet corresponding to the wheel speed The network signal is converted to the square wave signal.

Optionally, the excitation unit receives an output signal of the resolver and demodulates a motor speed signal; and the wheel speed detection method further includes: receiving the motor speed signal and converting the square wave signal.

Compared with the prior art, the technical solution of the present invention has the following advantages:

The technical solution utilizes the output signal of the resolver to perform conversion processing to detect the wheel speed, and can replace the conventional scheme of detecting the wheel speed by using the wheel speed sensor. In the hub motor technology, the hub motor, the resolver and the excitation unit are integrated in the wheel, and the conversion unit is an electronic device, which has a very small footprint compared to the wheel speed sensor. Therefore, the wheel speed detecting device can discard the wheel speed sensor, does not require additional external mechanical components, does not change the mechanical structure of the wheel, and does not substantially change the wheel structure and the wheel layout, and does not cause inconvenience to the wheel structure and the wheel layout.

DRAWINGS

1 is a schematic structural view of a wheel rotation speed detecting device according to a specific embodiment of the present invention;

2 is a flow chart of a method for detecting a rotational speed of a wheel according to an embodiment of the present invention;

In Fig. 3, Fig. 3(a) is an alternating excitation signal generated by an excitation unit in the wheel, and Fig. 3(b) is an output signal of the rotary transformer in the wheel;

4 is a conversion correspondence relationship between an envelope signal corresponding to the rotational speed of the motor and a square wave signal corresponding to the rotational speed of the wheel;

Fig. 5 is a structural view showing a conversion unit in the wheel rotation speed detecting device shown in Fig. 1.

detailed description

The above described objects, features, and advantages of the present invention will be more apparent from the aspects of the invention.

Referring to Fig. 1, in the hub motor technology, an in-wheel motor (not shown), an energizing unit 2, and a resolver 1 are integrated in the wheel, and the hub motor connects the wheels to drive the wheels to rotate. The excitation unit 2 provides an alternating excitation signal, and the resolver 1 is coupled to the hub motor and receives an alternating excitation signal from the excitation unit 2 to monitor the motor speed to produce an output signal including motor speed information.

The rotor of the resolver 1 is mechanically coupled to the rotor of the motor at a fixed rotational speed ratio. The rotor of the motor is mechanically coupled to the wheel at a fixed rotational speed ratio. The resolver 1, the rotor of the motor and the wheel have a fixed rotational speed ratio with each other, thus the wheel The rotation speed detecting method may include converting the output signal of the resolver 1 into a square wave signal, which is an ABS input signal corresponding to the wheel speed.

The present technical solution utilizes the output signal of the resolver 1 to perform conversion processing to detect the wheel speed, and can replace the conventional scheme of detecting the wheel speed by using the wheel speed sensor. The hub motor, the resolver 1 and the excitation unit 2 are all integrated components in the wheel, no additional external mechanical components are needed, and no mechanical improvement of the wheel structure is required. Therefore, the wheel speed detecting method of the present invention does not apply to the wheel. Structure and wheel layout bring inconvenience.

It should be noted that the "square wave signal corresponding to the wheel speed" is a square wave signal including wheel speed information. Referring to the prior art wheel speed detecting method, the wheel speed sensor can generate w square wave signals for every 360° rotation of the wheel, and the wheel speed can correspond to the number of sine waves generated per unit time. Therefore, in the technical solution, when the output signal of the resolver 1 is converted into a "square wave signal corresponding to the wheel speed", the ABS can receive w square wave signals per revolution of the wheel as a reference for conversion. Corresponding to different models, w is different, can be set according to specific conditions.

Referring to FIG. 2, the method of converting the output signal of the resolver 1 into a square wave signal may include: performing step S1, demodulating the package corresponding to the motor speed by using the output signal of the resolver 1 and the alternating excitation signal output by the excitation unit 2. The signal is output; step S2 is performed to convert the envelope signal into a square wave signal corresponding to the wheel speed.

Referring to FIG. 3(a), FIG. 3(a) is an alternating excitation signal Ur(t)=Vsinωt outputted by the excitation unit 2, and the alternating excitation signal Ur(t) is an alternating voltage. 3(b), FIG. 3(b) shows an output signal Us(t, θ)=Vsin ωtsin θ of the resolver 1, and θ is the rotation angle of the resolver 1.

The stator of the resolver 1 is stationary with respect to the wheel, and the rotor of the resolver 1 is connected to the rotor of the motor. The resolver 1 has ρ pole pairs. Therefore, the resolver 1 outputs ρ sine waves every time the motor rotates, and θ is the phase angle of the sine wave. Therefore, according to the principle that the resolver 1 detects the rotational speed of the motor, the θ is not the motor rotation angle, but may correspond to the motor rotational speed, and the envelope signal Vsin θ of Us(t, θ) contains the motor rotational speed information. Simultaneously obtaining Ur(t) and Us(t, θ), the envelope signal US1(t, θ) = Vsin θ containing the motor speed can be demodulated from Us(t, θ).

Step S2, the method for converting the envelope signal into a square wave signal may include:

First, according to the envelope signal US1(t, θ)=Vsinθ, the phase angle signal Δφ corresponding to the wheel rotation angle α in the square wave signal generation period Δt is calculated every time a square wave signal generation period Δt is obtained; Square wave signal generation phase in period Δt The bit angle signal Δφ produces the square wave signal.

In a square wave signal generation period Δt, the initial time is t1, the end time is t2, and Δt=t2-t1. At the initial time t1, US11(t1, θ) = Vsin θ(t1), θ(t1) is obtained by the inverse sine formula. At the end time t2, US12(t2, θ) = Vsin θ(t2), θ(t2) is obtained by the inverse sine formula. In the square wave signal generation period Δt, the rotation angle Δθ of the resolver 1 = θ(t2) - θ(t1).

Each time the rotor of the motor rotates, the resolver 1 outputs ρ sine waves, and the ratio of the motor speed to the wheel speed is s, and the wheel angle α=Δθ/(ρ*s) can be calculated. Each time the wheel is set to rotate, the ABS can receive w square wave signals, and the phase angle Δφ=(Δθ*w)/(ρ*s) corresponding to α. Therefore, Δφ = k * Δθ (k = w / (ρ * s)).

In the square wave signal generation period Δt, the number of cycles of the sine wave corresponding to Δφ is: Δφ/360=N+R, N is an integer and R is a remainder. The integer N is taken from it, converted into N periodic square waves and output. The initial time of each square wave signal generation period Δt is the end time of the previous square wave signal generation period Δt, and the end time of each square wave signal generation period Δt is the initial time of the next square wave signal generation period Δt.

Therefore, in conjunction with FIG. 4, FIG. 4 is a correspondence relationship between the envelope signal US1(t, θ)=Vsinθ corresponding to the motor speed and the square wave signal, and the square wave signal can be continuously generated in the continuous square wave signal generation period Δt. In the number of cycles of the sine wave corresponding to Δφ calculated in each square wave signal generation period Δt, the remainder R is counted in the next square wave signal generation period Δt.

The square wave signal is generated every other square wave signal generation period Δt, and the square wave signal generated each time may include N periodic square waves. The ABS receives a square wave signal every other square wave signal generation period Δt, and reads the number of occurrences of the high level to determine whether the wheel tends to lock.

As an alternative, the method for converting the envelope signal corresponding to the motor speed into the corresponding square wave signal may include: first, receiving an envelope signal corresponding to the motor speed and calculating an envelope signal corresponding to the wheel speed; and then, corresponding wheels The envelope signal of the speed is converted into square Wave signal. Please refer to the previous correspondence between the motor speed and the wheel speed. The envelope signal corresponding to the wheel speed can be directly calculated according to the envelope signal corresponding to the motor speed. The envelope signal corresponding to the wheel speed is a sine wave, which can be directly converted into a square wave.

In addition, the excitation unit 2 also receives the output signal of the resolver 1 and demodulates the motor speed signal. Therefore, as an alternative, according to the corresponding relationship between the motor speed and the wheel speed, the wheel speed detecting method may further include: receiving the motor speed signal from the excitation unit and converting the square wave signal into the square wave signal. With this option, it is not necessary to specifically demodulate the output signal of the resolver, and the square wave signal required by the ABS can be converted by directly using the motor speed signal output by the excitation unit.

The output signal of the resolver 1 includes Vsinωtsin θ and Vsin ωtcos θ, and the square wave signal corresponding to the wheel rotational speed can be obtained by Vsin ω tsin θ conversion. As an alternative, the square wave signal corresponding to the wheel speed can also be obtained by using Vsinωtcos θ conversion. At this time, it is necessary to pay attention to the phase difference between the cosine wave and the sine wave, and there is a delay in the process of converting into a square wave, so the conversion process Phase adjustment is required to obtain a square wave signal that meets the requirements.

Referring to FIG. 1, the wheel rotation speed detecting device may include a rotary transformer 1, an excitation unit 2, and a conversion unit 3. The resolver 1 is in communication with the excitation unit 2, and the excitation unit 2 outputs an alternating excitation signal to the resolver 1, which produces an output signal containing motor speed information and feeds it back to the excitation unit 2.

The conversion unit 3 is in communication with the resolver 1 for generating a square wave signal based on an output signal of the resolver 1, the square wave signal being an ABS input signal corresponding to the wheel speed.

The hub motor, the resolver 1 and the excitation unit 2 are integrated in the wheel, and the wheel rotation speed detecting means performs the conversion processing using the output signal of the resolver 1 in the wheel to detect the wheel rotation speed, which can discard the conventional wheel rotation speed sensor. Moreover, the conversion unit 3 belongs to the electronic device and has a very small footprint compared to the wheel speed sensor. Therefore, the wheel speed detecting device does not require additional external mechanical components and does not change the wheel's machine. The mechanical structure, therefore, the wheel speed detecting device of the present technical solution does not substantially change the wheel structure and the wheel layout, and does not cause inconvenience to the wheel structure and the wheel layout.

The wheel rotation speed detecting device further includes a demodulator 4 for receiving an alternating excitation signal from the excitation unit 2 and receiving an output signal from the resolver 1 to demodulate an envelope of the corresponding motor speed from the output signal of the resolver 1. signal. The converting unit 3 is configured to: receive the envelope signal and convert it into a square wave signal corresponding to the wheel speed, and send the square wave signal to the ABS.

The demodulator 4 and the conversion unit 3 can be integrated on one PCB board, and the PCB board takes up very little space, does not affect the wheel structure and affects the wheel layout. Thereafter, the PCB can be integrated in the excitation unit 2 so that no additional space is occupied.

Referring to FIG. 5, the conversion unit 3 includes an arithmetic unit 30 and a square wave generating unit 31. The operation unit 30 is configured to: receive an envelope signal from the demodulator 4 and calculate a phase angle signal corresponding to the wheel rotation angle in the square wave signal generation period every time a square wave signal generation period is calculated, and the operation method may refer to the foregoing wheel The relevant content of the speed detection method. The square wave generating unit 31 is configured to: generate a square wave signal according to the phase angle signal in each square wave signal generating period, and the specific method for generating the square wave signal may refer to the related content of the foregoing wheel speed detecting method.

The arithmetic unit 30 and the square wave generating unit 31 can be integrated together, for example, can be integrated into a Microcontroller Unit (MCU), and the occupied space is very small. The MCU and the excitation unit 2 can be integrated in the same housing.

As an alternative, the operation unit 30 may be configured to: receive an envelope signal corresponding to the motor speed and calculate an envelope signal corresponding to the wheel speed; the square wave generating unit 31 may be configured to: convert the envelope signal corresponding to the wheel speed into Square wave signal.

The excitation unit 2 can be integrated into a Power Electronic Unit (PEU) to provide an alternating excitation signal. The ADI series demodulation chip is also integrated in the PEU. The ADI series demodulation chip is used to receive the output signal of the resolver 1 and demodulate the motor speed signal. Therefore, as an alternative, the conversion unit can be directly The excitation unit 2 is in communication for receiving a motor speed signal from the excitation unit 2 and converting to the square wave signal. The demodulator 4, the conversion unit 3 and the excitation unit 2 can be integrated in the same housing, for example integrated in the housing of the PEU. Thus, the demodulator 4 and the conversion unit 3 effectively utilize the layout space of the PEU without the need to allocate additional layout space for the demodulator 4 and the conversion unit 3, which significantly reduces the influence on the wheel structure and the wheel layout.

Although the present invention has been disclosed above, the present invention is not limited thereto. Any changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention, and the scope of the invention should be determined by the scope defined by the appended claims.

Claims

A wheel rotation speed detecting device is integrated in a wheel: an in-wheel motor, an excitation unit and a rotary transformer, wherein the hub motor is connected to the wheel to drive the wheel to rotate;

The resolver is coupled to the hub motor and receives an alternating excitation signal from the excitation unit to monitor a motor speed to generate an output signal including motor speed information;

The vehicle wheel speed detecting device is integrated in the wheel, and includes:

And a converting unit, configured to generate a square wave signal according to the output signal, where the square wave signal is an ABS input signal corresponding to a wheel speed.
The wheel rotation speed detecting device according to claim 1, further comprising: a demodulator for receiving the output signal and the alternating excitation signal, and demodulating an envelope signal corresponding to a motor speed;

The conversion unit is configured to: receive the envelope signal and convert the signal into the square wave signal.
The wheel rotation speed detecting apparatus according to claim 2, wherein said converting unit comprises: an arithmetic unit configured to receive said envelope signal and calculate a square wave signal every time a square wave signal generation period is calculated Generating a phase angle signal corresponding to a wheel angle in a cycle;

And a square wave generating unit configured to generate the square wave signal according to the phase angle signal in each of the square wave signal generation periods.
The wheel rotation speed detecting device according to claim 2, wherein the conversion unit comprises: an arithmetic unit configured to receive an envelope signal of the corresponding motor speed and calculate Calculating an envelope signal corresponding to the wheel speed;

The square wave generating unit is configured to convert the envelope signal of the corresponding wheel speed into the square wave signal.
A wheel rotation speed detecting device according to claim 3 or 4, wherein said arithmetic unit and said square wave generating unit are integrated.
A wheel rotation speed detecting device according to claim 2, wherein said demodulator, said converting unit and said exciting unit are integrated in the same casing.
The wheel rotation speed detecting device according to claim 1, wherein the excitation unit is further configured to: receive an output signal of the resolver and demodulate a motor rotation speed signal; and the conversion unit is configured to: receive the The motor speed signal is converted to the square wave signal.
A wheel rotation speed detecting method is integrated in a wheel: an in-wheel motor, an excitation unit and a rotary transformer, wherein the hub motor is connected to the wheel to drive the wheel to rotate;

The resolver is coupled to the hub motor and receives an alternating excitation signal from the excitation unit to monitor a motor speed to generate an output signal including motor speed information;

The method for detecting a wheel speed includes: converting the output signal into a square wave signal, wherein the square wave signal is an ABS input signal corresponding to a wheel speed.
The wheel rotation speed detecting method according to claim 8, wherein the method of converting the output signal into a square wave signal comprises:

Demodulating an envelope signal corresponding to the motor speed by using the output signal and the alternating excitation signal;

Converting the envelope signal to the square wave signal.
The wheel rotation speed detecting method according to claim 9, wherein the method of converting the envelope signal into the square wave signal comprises:

Calculating, according to the envelope signal, a phase angle signal corresponding to a wheel rotation angle during a square wave signal generation period for each square wave signal generation period;

The square wave signal is generated based on the phase angle signal in each of the square wave signal generation periods.
The wheel rotation speed detecting method according to claim 9, wherein the method of converting the envelope signal into the square wave signal comprises:

Receiving an envelope signal corresponding to the motor speed and calculating an envelope signal corresponding to the wheel speed;

The envelope signal corresponding to the wheel speed is converted into the square wave signal.
The wheel rotation speed detecting method according to claim 8, wherein the excitation unit receives an output signal of the resolver and demodulates a motor rotation speed signal; and the wheel rotation speed detection method further comprises: receiving the motor rotation speed The signal is converted into the square wave signal.