WO2013004425A1

WO2013004425A1 - Redundant determination of the rotary motion of an electrical machine

Info

Publication number: WO2013004425A1
Application number: PCT/EP2012/059057
Authority: WO
Inventors: Chengxuan Fu; Wilfried Feuchter; Rene Bischof
Original assignee: Robert Bosch Gmbh
Priority date: 2011-07-04
Filing date: 2012-05-15
Publication date: 2013-01-10
Also published as: DE102011078586A1

Abstract

The invention relates to a circuit (2) for processing resolver sensor signals (28) in a vehicle, comprising a resolver sensor (4) installed to sense a rotary motion of a rotor (6) of an electrical machine (16), a resolver digital converter circuit (14) connected to communicate with the resolver sensor (4) and designed to control the resolver sensor (4) and to process the resolver sensor data (28), and a processor element (12) comprising a data connection (24a) on the resolver digital converter circuit (14) for transmitting processed resolver sensor data, characterized in that the processor element (12) has an additional data connection (24b) for transmitting further measurement data for the redundant verification of the processed resolver data.

Description

Description title

Redundant determination of the rotational movement of an electric machine

The present invention relates to drives for electric or hybrid vehicles. In particular, the present invention relates to a determination of a

Rotary movement of an electric machine. Furthermore, in particular, the present invention relates to a circuit for evaluating resolver sensor signals in a vehicle, a control device for a vehicle having a circuit according to the invention and a vehicle, in particular an automobile having a circuit according to the invention and / or an inventive control device.

State of the art

In electric or hybrid vehicles, a drive power of the vehicle is provided, at least in part, by an electric machine, thus an electric motor. For a preferred control of such an electric machine, it is usually helpful to determine accurate information about the current operating state of the electric machine.

For such a determination is usually a so-called resolver sensor on the electric machine use, which is used to detect rotational speed and angular position of the rotor position of an electric machine.

Speed and angular position are of central importance for motor control. An evaluation logic is used to evaluate the raw data supplied by the resolver sensor in such a way that the required measured variables speed and angular position are provided to a control device, for example as digital data values.

FIG. 1 shows a conventional resolver sensor with rotor excitation. Winding 10a is mounted on the rotor 6 of an electric machine. This winding is energized with a sinusoidal AC voltage. Two windings 10b, 10c mounted on the stator in perpendicular orientation receive a voltage induced by winding 10a.

In this case, the amplitudes of the voltages induced in the windings 10b, 10c are determined by the angle of the rotor or the winding 10a and correspond in each case to the sine and cosine of the angular position of the rotor.

Resolver sensor and Auswertelogik are usually only available.

FIG. 2 shows a conventional evaluation of a resolver sensor 4.

Control unit 20 in this case has microprocessor 12, which controls a resolver drive / evaluation circuit 14, a so-called resolver chip 14 or resolver digital converter circuit 14 by means of a reference signal 30. This is exemplarily supplied with a voltage of 5V _dc .

Resolver chip 14 in this case generates an excitation signal form by way of example, for example sinusoidal oscillation with 10 kHz and ± 2.5 V _Pea k- this

Sine wave is converted via amplifier element 18 into an excitation waveform with ± 10 Vpeak and fed to the resolver sensor 4 in winding 10a.

Area 26 thus represents the resolver drive. Resolver sensor 4 is shown schematically on the motor of an electric machine 16.

The resolver sensor data 28 are sent via filter element 22, e.g. one

Low-pass filter, in turn, the resolver chip 14 as a sine or cosine signals, supplied with, for example, ± 2.85 V _Pea k.

The resolver chip 14 itself is connected via data link 24a with microprocessor 12 and provides digital signal values with respect to rotational speed and angular position of the rotor of the electric machine 16 to the microprocessor 12. Furthermore, the microprocessor 12 via

Data connection 24a error information provided. Although the evaluation logic can include a simple diagnosis of the resolver sensor signals that detects various types of error resolver signals.

However, this error information regularly contains no errors that occur within the resolver chip because they are not sufficiently detectable, or the resolver chip does not have suitable internal precautions in order to be able to check even its proper function.

Thus, errors within the evaluation logic itself as well as the

Data transmission to a further processing microprocessor of a

Control unit mostly not recognize. These errors include, for example, register errors, data bit errors, addressing errors of the evaluation logic, frozen data, autonomous reconfiguration of the evaluation logic, as well as arithmetic unit defects, etc.

Such undetectable errors can thus result in the transmission of erroneous speed and angle values, which nevertheless are considered valid by a subsequent control device and can result in a, then faulty, control of the motor. Such faulty motor control can thus lead to such a faulty

Trigger control of the electric machine, so that this performs a situation-inadequate rotational movement, or works with an unwanted torque. The risk of "unwanted vehicle movement" or "unwanted vehicle movement direction" can also be caused by a failure of the resolver chip.

Such a faulty control, for example, to a

Accidental acceleration of the vehicle to block the drive axle, or even destroy the motor-driving IGBTs lead.

Disclosure of the invention

An aspect of the present invention can thus be seen in terms of errors within the evaluation logic of a resolver sensor as well as in the subsequent data transmission of the evaluated sensor signals from the evaluation logic a microprocessor, such as a control unit to recognize and thus avoid dangerous operating conditions.

In the light of this aspect, a circuit for evaluating resolver sensor signals in a vehicle, a control device for a vehicle having a circuit according to the invention, and a vehicle, in particular an automobile, comprising a circuit according to the invention and / or a control device according to the invention are provided according to the independent claims , Preferred embodiments will be apparent from the dependent claims.

The present invention thus relates to the redundant detection of a rotational speed, a direction of rotation, and angular position or the verification of information supplied by a resolver chip on the basis of further characteristics of a vehicle.

For redundant detection of the rotational speed, for example, one of the analog signals supplied by the resolver sensor can be processed or demodulated by a separate electronic circuit such that a digital frequency signal is generated from the supplied amplitude signal. Such a frequency signal can thus provide the rotor speed via its frequency, at least by means of one of the rotor speed proportional

Information.

This rotor speed proportional frequency can have another

Data connection are supplied to the microprocessor of a control unit. The microprocessor can then compare this information with the information directly supplied by the resolver chip and, for example, a

Deviation of the two information and thus detect a fault.

If not only one of the signals provided by the resolver sensor, but both analog resolver signals modulated by separate electronic circuits so that two digital frequency signals are generated, the direction of rotation of the rotor can be determined from the phase relationship of the two signals to each other. This information can also have one more

Data connection provided to the microprocessor of a control unit to verify the correct evaluation of the resolver sensor signals. In this case, in particular an in-phase demodulation of

Resolver sensor signals used with respect to the reference signal of the microprocessor.

As the demodulation circuit, a suitable amplitude demodulation circuit can be used. This can be realized for example by using an amplifier element, a diode element or generally a rectification element, a filter element, in particular low-pass filter element or by means of a Schmitt trigger element.

By using a demodulation element, an error in the evaluation logic can be detected by comparing the frequency of the demodulated digital signal with the rotor speed as provided by the resolver chip. When using two demodulation elements may be an error in the

Auswertelogik by comparing the frequency of the digital signals with the rotor speed and by comparing the direction of rotation of the

Digital signals and the sign of the speed of the resolver sensor data are detected.

Also, a calculation of speed, direction of rotation and angular position instead of with separate demodulation elements by means of another

Processor element, such as a digital signal processor (DSP) are performed.

For this purpose, a suitable digital signal processor with the two analog resolver sensor signals and the reference signal is applied and thereby forms a separate, redundant data processing and data evaluation. The analog resolver signals together with the reference signal can thus in the DSP or in a second microprocessor or under

Using a software microprocessor as part of a complex

Programmable Logic Device (CPLD) are evaluated by appropriate software.

The separate data processing in the DSP or the software used for this purpose forms, for example, the functionality of the evaluation logic of the resolver. Chips nach and thus independent of and redundant to this speed, direction of rotation and angular position determine.

These second values can now be compared with the values supplied by the resolver chip in order to detect errors in the evaluation logic. Of the

Microprocessor, to which both the resolver chip and the separate data processing unit (DSP or CPLD) is connected, can thus detect a difference by comparing the rotational speed values, the direction of rotation, for example, signs of the rotational speed, and by comparing the angle values detect an error.

However, the verification of the proper functioning of a resolver chip can also be provided by further vehicle data that is not supplied by the resolver sensor. In particular, a speed can under

Use of an external control unit to be checked.

For this purpose, in particular, a speed mechanically correlated with the electrical machine speed can be measured by another control unit by a separate sensor system. Usable is, for example, the wheel speed supplied by an ESP or ABS control unit with the connected via a fixed gear electric machine or even the engine speed of the engine, supplied by the engine control unit. Such speed information can subsequently be passed on via a communication interface, for example via a CAN bus or FlexRay to the engine control unit of the electrical machine.

By a subsequent comparison of the Resolver sensor speed supplied by the resolver chip with the externally measured speed, the speed value of the resolver chip can be checked for its correctness or plausibility.

Embodiments of the invention are illustrated in the drawings and explained in more detail in the following description. Show it FIG. 1 shows a resolver sensor;

Figure 2 shows an exemplary embodiment of a circuit of resolver sensor and resolver evaluation logic;

3a, b, an exemplary embodiment of an arrangement for

redundant evaluation of the resolver sensor signals;

FIGS. 4a, b show a further exemplary embodiment of a redundant resolver sensor signal evaluation according to the present invention;

FIG. 5 shows a further exemplary embodiment of a redundant resolver sensor signal evaluation according to the present invention; and

FIG. 6 shows an exemplary embodiment of a verification of the resolver sensor signal evaluation.

Embodiments of the invention

With further reference to FIGS. 3 a, b, an exemplary embodiment of an arrangement for the redundant evaluation of the resolver sensor signals is shown.

Figure 3a shows centrally resolver chip 14 and schematically resolver sensor 4. Using the amplifier element 18 with gain G resolver chip 14 controls the resolver sensor 4 via reference signal 30.

Due to the above-described functionality of the resolver sensor 4, two amplitude-modulated analog signals 28 are forwarded to the evaluation element 22, here exemplified as two amplifier elements with gain G, and fed back into the resolver chip 14. Resolver chip 14 evaluates the resolver signals 28 and passes them as digital information on speed and angular position using the data link 24a via a data bus to microprocessor 12 on. One of the two signals supplied by the resolver 28 is tapped in parallel and the

Demodulation element 32a supplied. In particular, a demodulation element in the context of the present invention may be a normal frequency demodulation circuit. This may, for example, as an amplifier element, a diode, a rectifier circuit, a

Low-pass filter or a Schmitt trigger element be realized.

Demodulation element 32a converts the analog resolver signal 28, shown in FIG. 3b as amplitude-modulated sine or cosine oscillation, into a digital rectangular signal, likewise shown in FIG. 3b, and forwards it to the microprocessor 12 via data connection 24b. This one points

For example, a General Purpose Timing Ray, which can evaluate the demodulated or digitized resolver signal with respect to its frequency, pulse width, period, etc. In particular, by evaluating the frequency or the period can be at a speed of the rotor 6 of the electric

Close the machine.

Still referring to FIGS. 4a, 4b, another example is shown

Embodiment of a redundant resolver sensor signal evaluation according to the present invention shown.

The arrangement of FIG. 4a substantially corresponds to the arrangement of FIG. 3a, but with two demodulator elements 32a, 32b in each case

connected to one of the resolver signals 28 are provided. The

Functioning of each demodulator element 32a, 32b is in this case

Essentially identical as previously described.

Each demodulator element 32a, 32b generates a digital rectangular signal from the amplitude-modulated analog signal of the resolver sensor 4, which, however, are shifted from one another by a fraction of a period, in particular by half a period. From the period of the digital signals and thus from their frequency can in turn close to the rotor speed, while the direction of rotation of the digital signals and the sign of the

Speed of the resolver evaluation can be removed. Still referring to FIG. 5, another example is shown

FIG. 5 has a further processor element 34, for example a digital signal processor. Both analog resolver sensor signals 28 and the reference signal 30 are fed to the further microprocessor 34. This is also connected to the microprocessor 12 via the further data connection 24b.

In the digital signal processor, for example, the functionality of a resolver chip can now be simulated in software. Thus, information comparable to those provided by resolver chip 14 to data processor 24a to microprocessor 12 may also be passed from digital signal processor 34 to microprocessor 12 via data interface 24b. By a simple comparison of data supplied via data links 24a and 24b data regarding speed, direction of rotation and angular position can be on a

proper function of resolver chip 14 and microprocessor 34 are closed.

Still referring to FIG. 6, an exemplary embodiment of a verification of the resolver sensor signal evaluation is shown.

In essence, FIG. 6 shows a known resolver sensor evaluation comparable to that of FIG.

Direction of rotation and angular position using the data link 24a to microprocessor 12 passes.

Via data connection 24b, microprocessor 12 receives further information from further control devices 36a, b, for example an ESP control device 36a or an engine control control device 36b. These other values can

For example, be the wheel speed of the ESP control unit 36a or the speed of an internal combustion engine of engine control unit 36b.

This information can be viewed together with the information supplied by the resolver chip 14 from the microprocessor 12 and thus on the Plausibility be checked. For example, information from the ESP control unit 36a about the standstill of the wheels and the information of the resolver chip 14, after which the rotor 6 of an electric machine 16 would rotate, indicate an error or an erroneous evaluation in the resolver chip 14.

Claims

claims

A circuit (2) for evaluating resolver sensor signals (12) in a vehicle

a resolver sensor (4) adapted to receive a

Rotary movement of a rotor (6) of an electrical machine (16); a resolver-to-digital converter (RDC) circuit (14) communicatively coupled to the resolver sensor (4), adapted to drive the resolver sensor (4) and to evaluate the resolver sensor data (28); and

a processor element (12) having a data connection (24a) to the resolver-to-digital converter circuit (14) for the transmission of

evaluated resolver sensor data;

characterized in that

the processor element (12) has a further data connection (24b) for the transmission of further measurement data for the redundant verification of the evaluated resolver sensor data.

Circuit according to claim 1,

wherein the further measurement data are also the resolver sensor data (28). A circuit according to claim 1 or 2,

wherein the resolver sensor (4) is arranged to output at least one sine or cosine amplitude-modulated analog signal (28); wherein a demodulator element (32a, b) is connected to the further data connection (24b) and receives at least one analog signal (28) in parallel with the resolver-digital converter circuit (14); and

wherein the demodulator element (32a, b) is arranged to convert the analogue signal (28) into a speed-proportional digital one Frequency signal to provide and forward to the processor element (12).

Circuit according to one of the preceding claims,

wherein the resolver sensor (4) is arranged to output a sinusoidal and a cosinusoid amplitude modulated

Analog signal (28);

wherein two demodulator elements (32a, b) are connected to the further data connection (24b) and each demodulator element (32a, b) receives one of the two analog signals (28) in parallel with the resolver-digital converter circuit (14);

wherein each demodulator element (32a, b) is arranged to provide conversion of the respective analogue signal (28) to a speed proportional digital frequency signal and to forward it to the processor element (12); and

wherein the processor element (12) is arranged to detect a direction of rotation of the rotor (6) of the electric machine (16) based on the phase relationship of the digital frequency signals to one another.

Circuit according to one of claims 3 or 4,

wherein the demodulator element (32a, b) is an element selected from the group consisting of amplifier element, rectifier element, diode element, filter element, low-pass filter element and Schmitt trigger element.

Circuit according to one of claims 1 or 2,

Analog signal (28);

wherein the resolver-to-digital converter circuit (14) provides a reference signal (30) for driving the resolver sensor (4);

wherein a further processor element (34) is connected to the further data connection (24b) and receives the two analog signals (28) in parallel with the resolver-digital converter circuit (14) and the reference signal (30); and

wherein the further processor element (34) is set up to evaluate the analog signals (28) and of the reference signal (30) in such a way that rotational speed, Direction of rotation and angular position of the rotor (6) of the electric machine (16) can be determined and forward this information to the processor element (12). 7. A circuit according to claim 1,

wherein the further measurement data are data of a separate sensor from the resolver sensor (4) or separate control device (36a, b) of the vehicle. 8. A circuit according to claim 7,

wherein the data is selected from the group consisting of wheel speed of an ESP or ASB control unit, engine speed of an engine control unit; and or

wherein the processor element (4) is set up to provide a plausibility comparison of the further measured data with the data of the resolver-digital converter circuit (14), in particular for the redundant verification of the evaluated resolver sensor data (28).

9. control unit (20) for a vehicle, comprising a circuit (2) according to one of the preceding claims.

10. Vehicle, in particular automobile, comprising a circuit (2) according to one of claims 1 to 8 and / or a control device (20) according to claim 9.