RU2312363C1 - Contactless programmable pickup of absolute angular position - Google Patents

Abstract

FIELD: automotive instrument industry.

SUBSTANCE: pickup comprises two mechanically disconnected and insulated members mounted with a spaced relation one with respect to the other. One member is made of the rotor unit, and the other member is made of a stator having a set of unmovable mechanical and electronic parts that send information on the angular position of the rotor with the magnet through the contact interface. The magnetic system of the pickup is made of a programmable unit, analogue output, and rotating cylindrical dipole diametrically magnetized magnet.

EFFECT: enhanced reliability.

8 cl, 24 dwg, 1 tbl

Description

The present invention relates to automotive electronic instrumentation and can be directly used in electronic vehicle control systems to determine the opening angle of the throttle, the degree of depressing the accelerator pedal, the position of the exhaust gas recirculation valve, the angular position of the camshaft, crankshaft, in other automotive systems requiring analog, PWM or serial signal about the absolute angular position of a rotating object (shaft), and also for non-contact detection of the absolute angular position of a large number of rotating objects in many other sectors of light and heavy industry.

An analogue of the claimed sensor is an accelerator pedal position sensor (United States Patent 4915075 dated April 10, 1990).

The device includes a potentiometer installed in the pedal and a board with a PWM signal generating circuit with an output duty cycle proportional to the position of the pedal.

The disadvantages of this device include the susceptibility to wear, characteristic of potentiometers, a short service life, low reliability, sensitivity to vibration and dust.

An analogue of the claimed device is an angular position sensor with a Hall device and a permanent magnet of a given shape (United States Patent 5159268 dated October 27, 1992.).

In the description of the device, two preferred variants of the shape of the magnet are indicated - oblong and bell-shaped, allowing to achieve high linearity during its rotation.

The disadvantage of this device is the complexity of the magnetic system, the need to use magnets of a special shape and the application of calculated mathematical methods.

An analogue of the claimed device is a magnetic angle sensor with improved output linearity (United States Patent 5444369 of August 22, 1995).

The device uses massive stationary axial magnetic circuits and a rotating magnetic circuit to which one or more magnets are attached.

The disadvantages of this device include cumbersomeness, structural complexity, the need to use both design methods and settings and adjustments when developing the device, lack of adaptability to the special requirements for the mechanics of automotive sensors operating in a limited range of rotation angles.

An analogue of the claimed device is a pedal position sensor with a magnet moving relative to a magnetic field sensor located in the stator channel (United States Patent 6577119 dated June 10, 2003).

The device is a non-contact position sensor in which the stator surface includes two areas of magnetic material, the magnet is mechanically connected to the accelerator foot pedal, the relative movement of which along one or two Hall sensors in the stator channel causes the formation of an electrical signal proportional to the movement of the magnet, which is processed in integrated sensor circuits and one or two external ASIC (Application Specific Integrated Circuit) with programming capabilities, for example, in the EEPROM linear output oh characteristics and temperature compensation as well as a signal for transmission over a serial protocol, such as CAN bus.

The disadvantage of this device is the complexity of the described magnetic system, the need to use two Hall sensors to improve measurement accuracy, one or two external interface ASICs to implement the required interface.

An analogue of the claimed device is an angular position sensor with two radial magnets mounted on the rotor, creating a working field, which when the rotor is rotated is measured by an external magnetic field sensor (preferably a magnetoresistive AMP sensor or a Hall sensor) (United States Patent 6806702 dated October 19, 2004) .

The disadvantage of this device is the bulkiness, the need to use two magnets and one or more external ASIC processors of the bridge signal; the functional angular range of the AMP sensor does not exceed 180 °.

Structural analogues of the claimed device are also:

non-contact vehicle speed sensor, designed to measure the angular speed of the gear rotor, using a magnetic circuit as part of a magnetically sensitive element to obtain a duty cycle close to two (RF Patent No. 35441 for utility model according to application No. 2003127267 of 08.09.2003, IPC G01P 3/488, registered in the State Register of Utility Models of the Russian Federation 10.01.2004);

a non-contact vehicle speed sensor that is built into the gearbox (RF Patent No. 36994 for utility model as per application No. 2003132947 dated 11.11.2003, IPC G01P 3/488, registered in the State Register of the RF PM March 27, 2004);

and non-contact vehicle speed sensor. (Decision on the grant of a patent for an invention No. 2004102133/28 (002114) dated January 26, 2004; conclusion dated April 12, 2004).

The use of these devices, the functional purpose of which is the detection of angular velocity, does not provide the ability to detect the absolute angular position in continuous real time.

The prototype of the proposed sensor is a measuring device for non-contact determination of the angle of rotation (United States Patent 6534971 dated March 18, 2003).

This device includes a rotor on which a permanent magnet with a diametrical direction of magnetization is located and a stator is a Hall element located asymmetrically and describing the elliptical rotational movement of the permanent magnet. However, no magnetic flux concentrators are used in this design. The indicated magnetic system makes it possible to obtain an output characteristic region with a steep lowering region and characteristic flat regions.

The disadvantage of this device is the narrowing of the range of the measured angle due to insufficient uniformity of the output characteristic (the description of the invention indicates the angular region of linearity to 80 °, while in many cases for the effective operation of the sensor it is necessary to measure angles of 100 ... 120 ° or more, up to 360 ° or for some types of devices angles of several full revolutions).

Conventional linear Hall effect sensors recommended for this prototype device have quite a few drawbacks: low sensitivity, sensitivity drifts, displacement and bias drifts, and significant non-linearity (up to 3% in the full range, which is usually less than 90 °).

The device also lacks special circuitry and mechanical means of adaptation to specific working conditions.

The objective of the invention is to simplify the design of the device and the technology of its assembly and installation, increase reliability and accuracy, increase linearity (absolute and relative linearity of the analog signal, duty cycle drift of the PWM signal or the accuracy of the transfer characteristic in absolute digital format), improve repeatability, expand the functional range and a linear portion of the measured angle to any value within 0-360 °, an increase in sensitivity, the development of adaptive traits to specific conditions work, direct replacement of analog three-wire and two-wire (PWM) potentiometers and classical sensors based on the Hall effect, the ability to flexibly adapt the device to integrate it into existing automotive systems, as well as for external (with respect to the detected automobile system) mounting the sensor on the shaft end , the ability to use various magnetic rotors, as well as ensuring the functionality of the device in conditions of significant static and dynamic system displacements.

The tasks are solved in that the non-contact absolute angle position sensor, in which a magnetic rotor with a magnet rotates the magnet in a detectable angular range relative to the fixed stator - the integrated circuit (IC) of the Hall effect magnetic field sensor, consists of two mechanically not interconnected and isolated each from each other parts with a constant air gap in the space between them, one part of the above absolute angle sensor is a rotor assembly, made of a material that does not conduct a magnetic field, with a magnet, during assembly according to the alignment results of a rigidly installed (pressed and glued) in the rotor assembly mechanically connected with the rotating shaft of the detected object (target) by means of an orientation flat or an orientation groove in the rotor mounting sleeve and having the ability to rotate from the outside of the device to a detectable angle φ within the full mechanical range of the device, another part of the above absolute angle polo sensor A stator is a set of fixed mechanical and electronic parts that provide information on the angular position of the rotor with a magnet through the contact interface, the rotor and stator of the above absolute angular position sensor are placed in space so that the light axis of magnetization and the base of the diametrically magnetized cylindrical rotor magnet its rotation are parallel to the front surface of the stator IC, which is a dual-axis magnet programmable in the EEPROM memory total angular encoder with an analog output, PWM interface or serial interface, formed by digitizing and digital processing on the integrated steps of the ADC-DSP using the arctangent function of the signals of the integrated cruciform array of planar Hall elements, sensitive to the gradient of the components of the working magnetic field perpendicular to the front surface of the above IC sealed by surface mounting on a printed circuit board with circuit components of the above sensor bsolyutnogo angular position.

The circuit of the aforementioned Hall sensor is a two-axis magnetic angular encoder that allows the format selection and programming after assembly of the entire device of the main parameters of its output transfer characteristic - analog, PWM or serial format characteristics - limiting output voltage levels and calibration points or zero position, direction of rotation magnet or the direction of inclination of the transfer characteristic, bias and gain (sensitivity) and (or) other parameters.

The output connector of the device housing contains only the functional terminals used in the further operation after programming the sensor, and only the functional terminals of the IC are used in the process of programming the device. No technological wire leads and (or) a wire loop of the auxiliary technological socket are not used during programming.

An axial and radial arrangement of the stator housing relative to the rotor, as well as an axial arrangement of the stator, equipped with an internal sleeve for the rotor assembly with an air gap between all stator surfaces and rotor surfaces adjacent to the above stator surfaces (for external installation).

The above IP with an array of planar Hall elements that are sensitive to the gradient of the components of the working magnetic field perpendicular to the front surface of the above IS can be equipped with an integrated magnetoconcentrating (IMC) disk (s), through which the rotation of the dipole magnet converts the parallel field components to the perpendicular front surface of the above IP.

When programming the above IPs, the choice of the output format, support for two- or multi-point calibration, the ability to program the main and auxiliary parameters of individual sections of the output transfer characteristic during multi-point calibration can be provided.

The base of the rotor diametrically magnetized cylindrical permanent magnet can be circular or annular.

For alignment, the magnet can be rigidly installed (pressed and (or) glued) in the sleeve with grooves used to indicate the position of the zero plane of magnetic symmetry (magnet poles), or under a screwdriver, rigidly installed (glued) in the rotor assembly according to the results of alignment of the magnet. Slots for indicating the zero position or for a screwdriver can also be made in the magnet body. Magnet painting can also be used to visually distinguish the poles.

To protect the above-mentioned Hall sensor from reverse voltage, overvoltage, output short circuit, impulse noise in the power supply and output circuits, if this protection is not provided in the integrated circuit of the above integrated Hall sensor, the device circuit located on the sensor circuit board may include the necessary protection circuits ( Zener diode, rectifier, filter capacitors, etc.).

A non-contact programmable angular position sensor in the range of 360 ° is shown in figures 1-24.

Figure 1-8 shows examples of designs of analog non-contact programmable absolute position sensors. Figures 1, 4, 6 show general (axonometric) views of the devices; Figs. 2, 3, 5, 7, 8 shows types of examples of sensors in section, illustrating the principle of operation of the claimed device.

Figure 1-5 shows the performance of devices designed for integration into automotive systems, with a sealing ring:

1 to 3 show an axial design of the device;

figure 4, 5 shows a radial design of the device.

Figures 6-8 show a design of a device for mounting above an end of an output shaft (external to the detected automotive system).

Figures 1, 2 and 6, 7 show a device embodiment in which the rotor assembly is provided with an adjusting sleeve-housing for a magnet with a groove identifying the position of the zero plane of symmetry (magnet poles), or used to adjust the magnet position with a screwdriver during assembly of the rotor assembly . Figure 3, 4, 5 and 8 show the design options of the device without an individual sleeve-body for a magnet, the poles of which are visually distinguishable.

In Fig.9 shows the corresponding Fig.1-8 embodiments of the rotor assembly.

Figure 10 shows an example of an electrical circuit diagram of the inventive device with programmable in the EEPROM IC biaxial magnetic angular encoder MLX90316 Melexis.

Figure 11 shows the functional diagram of the IC MLX90316.

On Fig shows the main elements of the magnetic system and illustrates the principle of operation of the inventive device.

On figa-g illustrates in detail the working principle of the sensor with an array of Hall elements and IMC, implemented in the technology "Triaxis" Melexis:

on figa shows the conversion of components In _|| parallel working magnetic field into perpendicular B _⊥ by means of IMC-disk for reading the field by planar Hall elements;

on figb shows the location of the IMC disk and the array of Hall elements on the substrate in the IC and the conversion of the parallel components of the magnetic field B _X and B _Y in the direction of the measuring axes X and Y;

on figv shows the principle of obtaining sinusoidal and cosine signals from an array of Hall elements for detecting the angle φ;

13 g shows the sine-cosine voltage signals generated at the primary stage of signal generation in the MLX90316 IC.

On Fig given an illustration of the working principle of a 12-bit analog biaxial magnetic angular encoder (DAC resolution of the analog output MLX90316 - 12 bits).

On Fig illustrates the principle of calculating the angle MLX90316 in the SOIC-8 package and shows examples of analog output characteristics of the IC MLX90316,

on Fig shows the output PWM interface MLX90316,

17 illustrates the receipt of a serial interface in the MLX90316.

On Fig shows examples of analog output modes of the inventive device, examples of designs of which correspond to figures 1-8, in a limited range of angle φ selected for these structures equal to 120 °, with the direction of rotation counterclockwise.

On Fig.19-22 shown:

a typical operating mode of a classic analog Hall sensor (figa);

the primary stage of the formation of the transfer characteristics (Fig.19b, c);

typical programmable output characteristics of the classic Hall sensor (Fig.20-22).

On Fig shows the analog output modes of the claimed device in comparison with an example of the characteristics of the classic Hall sensor and possible examples of the characteristics of typical IC encoders (for example, OTPROM AS5043 Austriamicrosystems once programmed in memory).

On Fig shows a comparison of the programming methods of the analog characteristics of the MLX90316 and the encoder IC AS5043:

on figa shows the programming of the zero position (offset) of the output characteristics of AS5043;

on figb shows a multi-point calibration of the output characteristics of the MLX90316.

The table shows the main technical specifications of the MLX90316.

A non-contact programmable sensor of absolute angular position, examples of the designs of which are shown in FIGS. 1-9, implements the operating mode of the device with the rotation of the dipole magnet in the range of the mechanical angle φ _max = 0 ... 360 °. As an example, to obtain analog functional characteristics (FIGS. 15 and 18), the detected mechanical angular value φ _max = 120 ° was selected. The programmed effective electric angle φ _eff and the linear portion φ _lin are also 120 °.

The non-contact programmable absolute angle encoder shown in FIGS. 1-9 consists of a rotor 1 (assembly unit of a rotor assembly) and a stator 2 mounted on one or more screws. There is a constant air gap between the rotor and stator d.

The rotor assembly 1 includes a rigidly mounted diametrically magnetized cylindrical permanent magnet 3, pressed in the versions shown in figures 1-2, 6-7 and 9a, in a plastic adjustment sleeve-housing 4 with a groove 13; the magnet assembly 3 with the sleeve 4 is pressed into the rotating installation sleeve 5. The magnet 3 without the sleeve 4 (also with a groove 13) (Figs. 1, 3, 4-5, 6, 8, 9b) is pressed directly into the rotating installation sleeve 5.

The stator 2 of the sensor includes a printed circuit board 6, on which the Hall sensor is sealed - a biaxial magnetic angular encoder 7 and the contacts of the connector 8.

To ensure the functionality of the inventive sensor, it is necessary to provide a working gap D between the magnet 3 and the Hall sensor 7, prescribed for this magnetic system (Fig.12-14).

The stator 2 of the sensor is performed as a single assembly. Roughly the assembly steps of the housing 2 with the components of the claimed device are determined by the following sequence. Initially, an electronic assembly is manufactured as an assembly with the upper or lower part of the housing 9, with the contacts of the connector 8 using the pouring or press-in technology. Integral Hall Sensor - a two-axis magnetic angle encoder 7 is mounted on the board 6 and sealed. The preferred mechanical arrangement of the sensor 7 on the board 6 relative to the housing 2 is selected constructively. The board 6 is installed in the groove of the upper part of the housing 9 of the stator 2. The contacts 8 are sealed on the board 6. Then the electronic unit with the housing part 9 is doused with plastic to form the lower part of the housing 10 (Figs. 1-5) or closed with a lid 10, which is then sealed ( 6-8).

The rotor 1 is mechanically connected with the rotating shaft of the detected object (target) 11 and has the ability to rotate from the outside of the base of the housing 2 by an angle φ = 0 ... 360 °. On the reverse side of the mounting sleeve 5 of the rotor 1 there are orienting grooves (or flat) for the exact pairing of the rotor assembly 1 with the shaft 11. The stator housing 2 is rigidly fixed with one, two or more screws to the fixed part of the object.

Devices designed to be embedded in automotive systems (FIGS. 1-5) are additionally equipped with a sealing ring 12.

The permanent magnet 3 (or the assembly of magnet 3 with the sleeve 4) is rigidly installed (pressed and glued) in the installation sleeve 5 of the rotor assembly 1 according to the results of alignment of the zero plane of symmetry of magnet 3, which is necessary to obtain identical technical characteristics of the batch of products.

Zero magnetic vector with a zero value of magnetic induction of the magnetic field (or easy axis of magnetization) in the inventive device can correspond to any mechanical position of the magnet 3 relative to the rotor 1, the mounting sleeve 5 and the stator housing 2, but the rotation of the zero vector (or light axis of magnetization) magnet 3 when programming the transfer characteristics must be consistent with the measuring principle of this IC, as shown in Fig.15 for analog characteristics MLX90316.

When programming the MLX90316, the limiting voltage levels U _ClampLo , U _ClampHigh , offset U _0q (voltage at zero field induction), tilt direction (direction of rotation of the magnet) and other parameters of the output characteristic are set.

For the inventive device, the circuit diagram of which is shown in Fig. 10, the MLX90316 is the first commercially available product. The measuring principle of the MLX90316 in the SOIC-8 package is shown in FIGS. 12-14. With this relative position of the magnetic poles of the magnet 3 and the IS 7 in the structures shown in figures 1-9, the zero angle of rotation of the magnet 3 relative to the IS 7 corresponds to a zero value of the magnetic induction of the field.

Given this mutual arrangement in the design of the sensor, the zero magnetic vector indicated by the groove 13 of the sleeve 4 or magnet 3 (Figs. 1-9) may coincide or differ from the zero reference vector of the effective electric angle φ relative to the stator housing 2 and IS 7 by a constant angular value , which in case of mismatch, it is advisable to take equal to φ _max / 2 (see Fig.15 and 18).

The rotation of the magnet 3 in the examples of structures shown in figures 1-8, is carried out counterclockwise relative to the front surface of the IC 7, which is set programmatically (Fig.18).

Since in serial production it is desirable to obtain identical characteristics of the claimed device, for this purpose it is advisable to install the magnet 3 according to the results of its alignment in the rotor assembly 1, which should be identical for a batch of manufactured products.

To install magnet 3, a sleeve 4 can be used, which is provided with a groove 13 for a screwdriver to enable preliminary orientation of the zero plane of symmetry or the easy axis of magnetization of magnet 3 (Fig. 9) before its rigid installation (according to the results of magnetic field measurements, for example, teslameter, gaussmeter calibrated linear Hall IC or using special hardware and software).

In addition, through the use of the sleeve 4 provides:

1) the ability to align the zero position of the magnet 3 during installation of the stator 2 or assembly of the rotor assembly 1;

2) increase in the working area of alignment with a small magnet 3 - the initial angular tolerances; while the dimensions of the sleeve 4 can be increased.

Instead of the alignment groove 13 of the sleeve 4 (Fig. 9a), the zero plane of symmetry of the magnet 3 can also be indicated by a groove 13 on the surface of the magnet 3 (Fig. 9b) or marked with paint. To visually distinguish between the poles, the magnet 3 can also be coated with two colors of paint.

In mass production, as well as in the case where the use of the sleeve 4 reduces the range of permissible working air gaps d and D (see Figs. 1-9 and 12-14), a variant with paint of one or two colors is preferable. The magnet 3 can then be combined with the sleeve 5 of the rotor 1.

In the inventive device can be used both of the above options for installing magnet 3. In all cases, the alignment of the magnet 3 relative to the sensor 7 is provided during installation of the rotor 1 and stator 2 of the claimed device or assembly of the mechatronic unit with rotor 1; according to the alignment results, magnet 3 (also in the case of application of the housing 4) is rigidly installed (sealed) in the rotor assembly 1.

3 - pin output connector of the housing 2 of the angle position sensor with MLX90316, the circuit diagram of which is shown in Fig.10, is intended to form an analog data channel (options shown in Fig.15, 18). Alternatives are a two-wire PWM interface or a serial IC interface shown in FIGS. 16 and 17, respectively.

In the process of programming the MLX90316, only the functional outputs of the IS 3 and the contacts of the connector 8 are used. No special wire leads, process jumpers and / or connectors are required for programming the device.

The programmable magnetic angle encoder MLX90316, recommended for the magnetic system of the inventive sensor, operating on the basis of the working principle shown in Fig.12-14, is the newest and most preferred component base existing at the time of filing this application, two-axis magnetic angle encoders supporting analog, PWM or serial interface.

MLX90316 is a hybrid absolute magnetic encoder IC in the range 0 ... 360 ° based on Melexis Triaxis ™ technology, the sensor part of which consists of one integrated magnetoconcentrating (IMC) disk 14 with a diameter of D _IMC on a CMOS substrate 16 IC 7 in SOIC-8 case (or two IMCs located on a double substrate in the TSSOP16 enclosure), and an integrated cross-shaped array (arrays) of mutually orthogonal planar Hall elements 15, located under the IMC 14, pairwise sensitive to X and Y directions, respectively, in a plane parallel to IP itsevoy surface 7 (Figure 13).

The use of IMC 14 provides the conversion of components _|| magnetic fields parallel to the surface of the IC 7, perpendicular to B _⊥ (figa-b). Due to this transformation, the physical sensitivity of the sensor is achieved specifically to the magnetic field components B _X and B _Y parallel to the surface of the IC 7, which, when the magnetic vector of dipole magnet 3 is rotated in the described magnetic system without IMI, dominates perpendicular. MLX90316 with IMC 14 and an array of planar Hall elements 15 produces an electrical display of the transformed IMC 14 of the working magnetic field B _⊥ perpendicular to the surface of the IC 7, to which the hall elements 15 of the IS 7 are sensitive.

Thus, an increase in the sensitivity of the sensor due to the effects of the concentration of the components of the magnetic field precisely in the direction of the measuring axes of the sensor X and Y simultaneously means a significant increase in the sensitivity of the sensor to the field components in the vertical axis Z, an increase in the touch distance D and, therefore, d (Fig. 1 -8, 13-14).

Functional diagram of the MLX90316 is shown in Fig.11, the technical characteristics are shown in the table.

In addition to the sensor part itself, the stages of signal processing in the IC include multiplexing (MUX), amplification, ADC, DSP with a microcontroller, RAM, ROM and EEPROM. Then the received digital value is converted into an analog, PWM or serial signal.

The first stage of the circuit is designed to encode mechanical angle signals into two differential signals with a phase difference of 90 ° - sine and cosine (Fig.13g). Sine-cosine signals U _X and U _Y , proportional to the magnitude of the magnetic flux, are processed in a differential analog circuit using classical techniques for canceling shifts ("spinning" and "chopper" - a stabilized amplifier that allows you to achieve bias values of the order of several μT), and then ADCs are digitized with a resolution configurable in 14 or 15 bits, and transmitted to the DSP block.

The main element of the DSP unit is a 16-bit RISC microcontroller that uses the digital representation of the signals to calculate the angle using the arctangent table function applied to the signal ratio U _Y / U _X :

The ADC and DSP block provide a highly accurate calculation of the angular position of the magnet relative to the IC (the angle of rotation of the magnetic vector parallel to the surface of the IC).

The DSP functionality is controlled by a special microcontroller microcode (firmware - F / W) stored in ROM memory.

In addition to the "ATAN" arc tangent function, the F / W microcode controls the entire analog circuit, output transfer characteristic, output protocol, calibration, programming, and self-diagnosis modes.

Since the “ATAN” function is calculated from the ratio U _Y / U _X (as when using magnetoresistive sensors), the angular information is independent of variations in flux density when the air gap D or d changes, magnetic inhomogeneities, temperature effects, inconsistencies of the two quadrature signals U _Y and U _x .

The MLX90316 Hall IC has the ability to measure angles of 0 ... 360 °, unlike AMP sensors (0 ... 180 °) and classical Hall sensors (0 ... 120 °) with high linearity, regardless of the relative position of the IC and the poles magnet in construction.

In the described magnetic system (Figs. 12-14), the axis of rotation of the cylindrical dipole magnet 3 should be centered with the array of measuring elements 15, being the reference point of the polar coordinate system for determining the angle (rotation of the easy axis (Fig. 14), but the measurement principle under consideration is stable also to the displacements of the magnet 3 relative to its optimal position in the plane of the measuring axes X, Y.

The current digital angle value can then be converted by a 12-bit DAC into analog form (Figs. 10, 14, 15, 18). Other types of output format supported by the IC are 12-bit PWM (Fig. 16) and serial output (see Fig. 17 and table).

As mentioned above, the output transfer characteristic of the sensor is fully programmable (offset U _0q (rms voltage), gain, limiting levels U _ClampLo , U _ClampHigh ) directly under operating conditions, and, unlike once-programmable encoders, for example Austriamicrosystems, programming of operating settings and MLX90316 coefficients are executed in a reprogrammable non-volatile EEPROM.

When programming with the RTS-04 Melexis kit the transfer characteristics shown in FIG. 15, for examples of the inventive sensor designs shown in FIGS. 1-8, the following parameters are set:

- output (transfer characteristic) - analog voltage U (φ);

- lower limit level ClampLo = 0.25 V (U _ClampLo ) for φ≤0 ° (or for φ≤-60 °, or φ≤300 °);

- upper limit level ClampHi = 4.75 V (U _ClampHigh ) for φ≥120 ° (or for φ≥60 °);

- offset V _offset (U _0q ) = 2.25 V or 0V;

- the direction of rotation selected in the structures shown in figures 1-8,

- counterclockwise: CLOCKWISE = CCW = 1 (in other designs of the claimed device, the direction of rotation may be different - clockwise - CW);

- Slow (accurate) high-speed DSP operation mode HIGHSPEED = 0 (Slow Mode).

As mentioned above, since the programming of the IC is carried out through the functional outputs, only the functional outputs of the sensor are included in the contact interface. There are no sensor conclusions that are not used later after programming it in the reprogrammable EEPROM memory in the inventive device, which means simplifying the design of the device and the technology of its assembly and installation.

An alternative IC element base for structures of this type is magnetic angular encoders with serial, linear analog or PWM output, designed for one-time programming using special outputs (10-bit AS5040 / 3 Austriamicrosystems ICs, 12-bit AS5045 ICs with PWM output) , programming only in the factory (AM512 RLS ICs), as well as encoders with special pin configuration (iC-MA iC-Haus).

MLX90316 supports all of the above types of output formats; based on this IP, universal non-contact structures can be made (Figs. 1-8), the output format of the transfer characteristic of the inventive sensor, the angular range and other parameters are flexibly adjusted (programmed) to work as part of any automobile system.

It should be noted that the MLX90316 allows you to get exactly the analog characteristic, for example, for the throttle position sensor (Fig.6-8), optimal from the point of view of unification and compatibility with existing automotive systems, which can be programmed after assembly of the device within the entire mechanical angular range φ _max within 0 ° ≤φ≤120 °, which will be both the full range of φ _eff (φ _eff is the effective electric angle or the full range) and the functional linear angular range ohm φ _lin (see Fig. 15, 18).

The use of a programmable IC of a biaxial angular encoder in combination with a rotating permanent magnet creating a working field allows one to obtain four (by the number of Hall elements) or two analogue working signals (Fig. 13 g) in the range 0 ... 360 °, which is equivalent to using four or at least two analog Hall sensors of the classical type in alternative designs and means simplifying the design, assembly technology and installation of the claimed device in comparison with analogues and prototype.

Due to the build quality and uniformity of the magnetic surfaces of the magnet, a further increase in the accuracy and repeatability of measurements, an increase in reliability is achieved.

Special attention is paid to the choice of magnets: magnets should be cylindrical in shape, diametrically magnetized. In the designs shown in figures 1-9, a ⌀6 × 3 magnet is used.

The magnetic material can be any of the following types: AlNiCo, SmCo _5, or NdFeB. In automotive systems with elevated operating temperatures, SmCo is the most preferred material, having better thermal stability properties.

A magnetic field perpendicular to the surface of the sensor array should be approximately ± 50 mT in a radius of about 1 mm (see table). Magnets of other geometries can also be used in the design of the sensor, but this can affect the distance D to the IC (distance d between the rotor and stator).

With a ⌀6 × 3 magnet, the recommended working magnetic field is achieved at a distance of D = 0.5 ... 1.5 mm to the surface of the IC (plus 0.46 mm to the surface of the IMC).

The maximum flux density for ICs with IMC cannot exceed ± 1 T (± 700 mTl is recommended for MLX90316), so in strong fields, IMC induces significant non-linearity.

Unlike classical Hall sensors, the magnets used in the inventive device are smaller and may be weaker; the described measuring principle of the inventive device provides improved temperature accuracy, the ability to measure 360 ° angles with high linearity, independent of the mutual position of the IC and the poles of the magnet in the structure (in contrast to the classical measuring principle of Hall sensors - see Fig. 19).

The diametrically magnetized cylindrical magnet for Hall encoders is much smaller than the magnets for AMP sensors used previously in a similar measuring configuration (as shown in Fig. 12), with the possibility of detecting angles in the range φ = 0 based on the AMP effect ... 180 °.

The high sensitivity of the magnetic angular Hall encoders, after amplification, is comparable with the sensitivity of the AMP effect (of the order of 20 mV / mTl), it allows the use of a working air gap d in all structures (Figs. 1-9), sufficient to isolate the rotor and stator from each other.

Unlike alternative devices based on the AMP effect, which require a special bridge signal processor, the number of external discrete components in the sensor circuit is minimal.

The design of the inventive sensor is characterized by simplicity, manufacturability, reliability, a minimum set of mechanical and electrical components and a maximum set of adaptive features to specific working conditions.

The inventive sensor of the absolute angular position on the Hall effect reflects, first of all, the separation of the device into two parts - rotor and stator, which are not physically contacting each other (with a constant air gap between them). The functioning of the inventive sensor in the angle range 0 ... 360 ° is carried out on the basis of the magnetic system described above and shown in Fig. 12, with a biaxial magnetic angular encoder programmable in the EEPROM and a cylindrical dipole magnet, the magnetic vector of which is rotated parallel to the front surface of the IC .

Dividing the device into two parts allows you to reduce the number of mechanical components involved in the physical implementation of the magnetic system, and to minimize their mechanical contact, thereby improving reliability and increasing product life; due to the possibility of using various magnetic rotors and programming after assembly, the adaptability of the device to specific working conditions is increased.

Dividing the housing into two separate parts - the rotor and the stator - allows you to adjust (usually increase) the magnetic sensitivity of the sensor (the steepness of the working magnetic signals), use smaller working gaps D and d and weaker magnets, or, conversely, large gaps D and d with slightly stronger magnets than specified by the sensor IC specification (MLX90316 working field should be less than ± 700 mT).

Increasing the sensitivity of the claimed device also means that the amplitude of the working sinusoidal and cosine working signals increases, which in this case will be more noise-resistant.

With small working gaps d (D), the location of the microcircuit inside the stator housing of the sensor completely eliminates the risk of its physical destruction due to axial beats of the detected shaft (camshaft, throttle actuator, pedal, etc.), and mechanical vibration.

Due to the introduction of orienting grooves (flats) in the mounting sleeve of the sensor rotor and the sleeve - magnet body for fast mechanical adjustment of the magnet position with a screwdriver, technological design is ensured. Flats in the sensor mounting sleeve, a groove for a screwdriver in the body or body of the magnet, or the ability to visually distinguish the poles when painting the magnet provide identical technical specifications for mass-produced products.

The absence of any mechanical limiters of the axial displacement of the rotor with the magnet and the measured angle (for example, stops in the stator housing of the sensor and the protrusions of the rotor), which is achievable precisely due to the possibility of programming the inventive device after its complete assembly and (or) installation, also means simplifying the design and improving the manufacturability of the device.

In total, due to the separation of the housing into the rotor and stator parts that are not physically contacting each other (with a constant air gap between them), the use of only a minimum set of orienting grooves in the design nodes and due to the programming of the transfer characteristic after assembly and (or) installation is achieved increased reliability, improved measurement accuracy, repeatability of the claimed device.

In the future, due to the capabilities of the integrated encoder signal processing circuitry, IC programming in EEPROM in specific operating conditions, the availability of a ready-made analog, PWM or serial interface and integrated protection circuits, the accuracy of the sensor increases, adaptability to specific operating conditions develops, and the minimum number of circuit components is ensured and sensor contacts.

Programming after assembling the entire device the main parameters of its analog, PWM output characteristics or characteristics in a serial format - limiting levels of the output voltage and calibration points, direction of rotation, displacement and amplification (sensitivity) and (or) other parameters provides an arbitrary or optimal design (for serial production) the choice of the position of the zero plane of the magnetic symmetry of the rotor magnet relative to the stator housing of the sensor, which also increases adaptability l devices.

Minimization of electronic components is achieved through the use of Hall encoder ICs with a high degree of integration (the minimum set of external interface components is used only in the absence of identical integrated tools).

A significant advantage of the claimed device is its ability to detect the maximum mechanical angular range φ _max .

On Fig shows a comparison of the classical transfer characteristics of the Hall sensor (the operation of the classic Hall sensors is illustrated in detail Fig.19-22), the modes of an alternative device based on AS5043 and an example of the output characteristics of the inventive device. Figure 23 illustrates the expansion of the maximum mechanical φ _max , effective electrical φ _eff, and linear ranges φ _{lin of} measured angles φ in the inventive sensor (1 - output characteristic of the classic Hall sensor; 2 - high-linear analog mode of the claimed device; 3, 4 - diagnostic analog modes of the device AS5043).

Figures 19-23 show that the classic Hall sensor allows only a very small full range φ (effective electric angle φ _eff = 90 °, the linear range φ _lin with no more than 80 °) due to the working magnetic field B ( or the Hall voltage signal U _H ) during rotation of the magnet is a sinusoidal signal B (φ), which is linearly approximated in the range of the effective electric angle φ _eff , usually not exceeding 100-120 ° (Fig. 19c, Fig. 20). Conventional Hall sensors are significantly affected by magnetic inhomogeneities and non-equalization tolerances, which means the presence of some non-zero bias B _off or (-B _off ) of the Hall sensor with sensitivity σ (Fig. 19b), as well as the influence of temperature bias drifts ± B _off and sensitivity σ.

The standard analog transfer characteristic of a classic Hall sensor programmed in EEPROM for two calibration points at the linear range boundaries is shown in Fig. 20. On Fig shows the definition of the rms 50% duty cycle at zero magnetic induction field B and PWM outputs at the calibration points for a device based on the classic Hall sensor with PWM transfer characteristic. In contrast to the classical (Fig.21), PWM transfer characteristic of the inventive device (Fig.16) is independent of the position of the poles of the magnet.

Programming a classical linear Hall sensor with EEPROM at two calibration points allows obtaining the angular position in the normalized reference scale (output characteristics U (φ) proportional to the supply voltage U _pit = 5 V (Fig. 22). During the programming process, the rms voltage U _0q and stored estimated value of the magnetic susceptibility _M S example RMS voltage U _0q1, U _0q2, U _0q3 and sensitivity S _M1, S _M2, S _M3 signals 1, 2 and 3 shown in Figure 22 (1 - bipolar characteristic (classical Separated) 2 - unipolar characteristic; 3 - inverted unipolar characteristic).

Programming of the inventive device in EEPROM is performed similarly, but in the linear range of φ _lin within the full range of the effective electric angle φ _eff = φ _lin = 0 ... 360 °.

On the example of the characteristics of the sensor with AS5043 in Figs. 23 and 24a, it is shown that the linear range detected by the alternative device can take values in the range 0 ... 360 ° programmed during assembly, when the value range is selected 360 ° / 180 ° / 90 ° / 45 °. Depending on the actual angle programmed within 0 ... 360 ° of the zero position and zero offset, the transfer characteristic of the AS5043 may electrically “rotate” (see FIG. 24a).

Within the programmed angular range, the slope of the AS5043 characteristic can be further controlled by changing the gain of the output gain stage.

In contrast to the alternative device described above, the analog mode of the inventive device with MLX90316 allows you to get the output characteristic precisely within the functional or full mechanical range of the detected angle (Fig.24b), formed by two or more calibration points.

MLX90316 supports point-to-point or multi-point calibration of the transfer characteristic (Fig.24b). For most automotive sensors, only two-point calibration is sufficient, but the ability to accurately correct the signal, which in some cases can also be used, is an advantage of the claimed sensor.

Thus, high linearity of the output signal (<2%) and accuracy (≤ ± 0.5 °) are ensured to a large extent due to the use of high integral technologies in the device based on the described magnetic system: the differential principle of the quadratic array of elements, methods for eliminating bias , for example, "spinning current", "chopper-stabilization", computational and interface capabilities of encoders (embedded in their theoretical principles), programming the output characteristic in the EEPROM memory after complete assembly of the claimed device properties (using only functional findings).

Thus, the main differences of the claimed device from its predecessors are:

1) a rotor with a magnet and a stator - a set of stationary mechanical and electronic parts that provide information on the angular position of the rotor with a magnet through a contact interface, are two parts that are completely mechanically completely unconnected and isolated from each other in space; in the nodes of the device, only the minimum set of necessary mechanical components (orienting grooves) is used;

2) the use of a non-contact programmable magnetic system sensor in a design mode optimized for specific operating conditions, which implements a rotation of the direction of the magnetic vector of a cylindrical dipole magnet within the detectable angle parallel to the front surface of the IC of a two-axis angular Hall encoder (with IMC) with an adaptable output characteristic;

3) the output transfer characteristic of the inventive sensor is fully programmable for two or more calibration points in the memory of the EEPROM IC using only functional conclusions after assembling the entire device.

It is these differences that further simplify the design of the device and the technology of its assembly and installation, increase the reliability and accuracy of measurements, linearity (absolute and relative indicators of linearity of the analog signal, drift of the signal duty cycle or accuracy of the transfer characteristic in absolute digital format), improve repeatability, expand the functional range and a linear portion of the measured angle to any value within 0 ... 360 °, an increase in sensitivity, the development of adaptive signs specific operating conditions, including the direct replacement of analog three-wire and two-wire (PWM) potentiometers and classical sensors based on the Hall effect, flexible adaptation of the device to be integrated into existing automotive systems, as well as when using it for an external (with respect to a detected automobile system ) mounting on the shaft end, with the possibility of using various magnetic rotors, as well as the implementation of the functionality of the device in conditions of significant static and dynamic their systemic biases.

Table Specifications of Hall IC - Biaxial Angle Encoder MLX90316 Hall IP MLX90316 Technology Tria⊗is ™ (array of planar Hall elements with IMC) Functional Description 12/14 bit programmable magnetic angle encoder Supply voltage 5 (4.5 ... 5.5); absolute range -10 ... + 20 Consumption Current, mA 10 (slow mode - Slow mode); 16 (fast mode - Fast mode) Output interface 12-bit analog, 12-bit PWM output with programmable frequency 100 Hz-1 kHz or serial protocol for transmitting angular information with a resolution of up to 14 bits Programmable Parameters and Modes Limiting levels, gain (sensitivity), bias; output format (analog, PWM or serial output), many other settings: rotation direction, DSP speed, PWM frequency, low-pass filter parameters, diagnostic modes, blocking, 40-bit identification number, etc. The frequency of rotation of the magnet, rpm - * Working magnetic field, mT 50 (20-70); ± 700 mTl maximum Working gap between the IC and the magnet, mm '- * Update rate, kHz / Update time, μs 600 μs (Slow mode); 200 μs (Fast Mode) Power-on time, ms 15, in slow and fast modes Maximum angular alignment error, ° ^' - * Magnetic nonlinearity,% ^' - * Integral nonlinearity with optimal alignment of the magnet, ° ± 2 Integral Nonlinearity, ° ± 4LSB ** Differential nonlinearity, ° 0.05-2LSB ** Transient Noises, ° 0.03-0.06 in slow mode; Slow mode; 0.1-0.2 in fast mode Fast mode Operating temperature range, ° С S (-20 ... 85 ° C); E (-40 ... 85 ° C); K (-40 ... 125 ° C) Housing Types DC (SOIC-8), GO (TSSOP-16) Manufacturer Melexis LSB ** - Least significant bit; least significant least significant bit

Claims (9)

1. A non-contact programmable absolute angle position sensor in the range of 360 °, in which the magnetic rotor rotates the magnet in the detectable angle range relative to the fixed stator - an integrated circuit (IC) of the Hall effect magnetic field sensor, characterized in that the above absolute angle position sensor consists of of two mechanically not interconnected and isolated from each other parts with a constant air gap in the space between them, one part of the above absolute sensor A clear angular position is a rotor assembly made of a non-magnetic field material with a magnet, during assembly according to the alignment results, is rigidly installed (pressed and glued) in the rotor assembly mechanically connected to the rotating shaft of the detected object (target) by means of an orientation flat orientation groove in the rotor mounting sleeve and having the ability to rotate from the outside of the device case to an angle φ, detected within the full mechanical range of the device, each part of the above absolute angular position sensor is a stator - a set of fixed mechanical and electronic parts that provide information on the angular position of the rotor with a magnet through the contact interface, the rotor and stator of the above absolute angular position sensor are placed in space so that the easy axis of magnetization and the base the diametrically magnetized cylindrical rotor magnet during its rotation parallel to the front surface of the stator IC, is which is a programmable in the EEPROM memory IC of a two-axis magnetic angular encoder with an analog output, a PWM interface, or a serial interface formed by the results of digitization and digital processing on the integrated steps of the ADC-DSP using the arctangent function of the signals of the integrated crosswise array of planar Hall elements sensitive to the gradient of components working magnetic field perpendicular to the front surface of the above IP, sealed by surface mounting on a printed circuit board with circuit components of the above absolute angle sensor, the above magnetic field sensor - a biaxial angular Hall encoder allows format selection and programming after assembly of the entire device the main parameters of its output transfer characteristic - analog, PWM or serial format characteristics - limiting output voltage levels and calibration points or zero position, direction of rotation of the magnet or direction of inclination of the transfer characteristic, cm scheniya and gain (sensitivity) and (or) other parameters, the connector device housing comprises only functional terminals used in the further process operation after programming the sensor, the only functional IP terminals used during device programming. 2. A non-contact programmable absolute angular position sensor in the range of 360 ° according to claim 1, in which both the axial and radial positions of the stator housing relative to the rotor are allowed, as well as the axial version of the stator, equipped with an internal sleeve for the rotor assembly with an air gap between all stator surfaces and rotor surfaces adjacent to the above stator surfaces. 3. The non-contact programmable absolute angular position sensor in the range of 360 ° according to claim 1, in which the aforementioned IC with an array of planar Hall elements, gradient-sensitive components of the working magnetic field perpendicular to the front surface of the aforementioned IC, is equipped with an integrated magnetically concentrating (IMC) disk (s) ), by means of which (during rotation of the dipole magnet, the parallel field components are converted to perpendicular to the front surface of the above IP. 4. A non-contact programmable absolute angular position sensor in the range of 360 ° according to claim 1, wherein the stator IC is a two-axis angular Hall encoder with support for two- or multi-point calibration, with a programmable output transfer characteristic that allows the choice of the output format, programming of the main and auxiliary parameters of individual sections of the output transfer characteristic for multi-point calibration. 5. The non-contact programmable absolute angular position sensor in the range of 360 ° according to claim 1, in which the base of the rotor diametrically magnetized cylindrical permanent magnet is a circle or ring. 6. The non-contact programmable absolute angular position sensor in the range of 360 ° according to claim 1, in which for alignment the magnet is rigidly mounted (pressed and (or) glued) in the sleeve with slots to indicate the position of the zero plane of magnetic symmetry (magnet poles) or screwdriver rigidly installed (glued) in the rotor assembly according to the results of alignment of the magnet. 7. A non-contact programmable absolute angle position sensor in the range of 360 ° according to claim 1, in which grooves are made in the magnet body to align the magnet (indicate the position of the zero plane of magnetic symmetry (magnet poles) and (or) a screwdriver). 8. A non-contact programmable sensor of absolute angular position in the range of 360 ° according to claim 1, in which a magnet painting is used to visually distinguish the poles. 9. A non-contact programmable absolute angular position sensor in the range of 360 ° according to claim 1, in which to protect the above Hall sensor from reverse voltage, overvoltage, output short circuit, impulse noise in the supply and output circuits, if this protection is not provided in the integrated circuit of the above integrated Hall sensor, the device circuit located on the sensor board contains the necessary protection circuits (zener diode, rectifier, filter capacitors, etc.).

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