Hall Validity

Compute rotor spin direction and validity of Hall sensor sequence

Since R2020a

• 

Libraries:
Motor Control Blockset / Sensor Decoders

Description

The Hall Validity block checks and validates every state of the Hall sensor output sequence. The block identifies the condition when one or more Hall sensors are in an invalid state.

The block executes when a Hall sensor output state (or Hall state) changes.

Examples

Hall Offset Calibration for PMSM

Calculates the offset between the rotor direct axis (d-axis) and position detected by the Hall sensor. The field-oriented control (FOC) algorithm needs this position offset to run the permanent magnet synchronous motor (PMSM) correctly. To compute the offset, the target model runs the motor in the open-loop condition. The model uses a constant (voltage along the stator's d-axis) and a zero (voltage along the stator's q-axis) to run the motor (at a low constant speed) by using a position or ramp generator. When the position or ramp value reaches zero, the corresponding rotor position is the offset value for the Hall sensors.

• Open Model

Field-Oriented Control of PMSM Using Hall Sensor

Implements the field-oriented control (FOC) technique to control the speed of a three-phase permanent magnet synchronous motor (PMSM). The FOC algorithm requires rotor position feedback, which is obtained by a Hall sensor. For details about FOC, see Field-Oriented Control (FOC).

• Open Model

Ports

Input

HallVal — Current Hall sensor output state

scalar

The Hall state at current time. These are the possible input values (three-bit numbers where the MSB represents the output of the first Hall connected):

• 5 - (101)

• 4 - (100)

• 6 - (110)

• 2 - (010)

• 3 - (011)

• 1 - (001)

Note

The output port Invalid indicates a bad hall sensor condition.

Data Types: uint8 | uint16 | uint32

PrevHallVal — Previous Hall sensor output state

scalar

The Hall state prior to the current state.

Data Types: uint8 | uint16 | uint32

Cnt — External counter value

scalar

The external counter value that the block uses to determine the time elapsed between the Hall state change and block execution.

Note

The counter must reset when a Hall state changes.

Data Types: uint8 | uint16 | uint32

PrevDir — Rotor spin direction during previous Hall state

scalar

The direction of rotor spin (either +1 or -1 indicating positive or negative direction of rotation, respectively) during the previous Hall state.

Data Types: int8 | int16 | int32

Output

Invalid — Indicator of Hall state validity

scalar

The indicator of Hall sensor validity during the current or previous Hall state. The block checks the validity of the sensors by comparing the values of the HallVal and PrevHallVal input port with the value of the Expected hall sequence in positive direction parameter. The port can output these values:

• 1 – (001) Indicates that one (or more) sensors are bad.

• 0 – (000) Indicates that all sensors are good.

Data Types: single | double | fixed point

SpdCnt — Count at Hall state change

scalar

The value of the Cnt input port when a Hall state changes.

Note

The counter must reset when a Hall state changes. Therefore, this port indicates the number of counts during the previous Hall state.

Data Types: single | double | fixed point

Dir — Rotor spin direction during current Hall state

scalar

The direction of the rotor spin (either +1 or –1 indicating positive or negative direction of rotation, respectively) during the current Hall state. The block computes the direction by comparing the values of the HallVal and PrevHallVal input ports with the value of the Expected hall sequence in positive direction parameter.

Data Types: single | double | fixed point

SpdVal — Validity of current and previous Hall states and speed calculation

scalar

The port outputs zero when either one or both conditions occur:

• The block detects a bad hall sensor state (in either HallVal or PrevHallVal input port values).

• The block detects a change in the rotor spin direction.

The zero value indicates that you cannot calculate the valid speed for the current Hall state because the current value of SpdCnt is invalid. The port outputs the value one to indicate that a valid speed calculation is possible.

Data Types: single | double | fixed point

HallChng — Set flag to one, indicating Hall state change

scalar

The port outputs the value one (and sets the Hall state change flag to one) after the Hall state changes and the block has completed execution.

Data Types: single | double | fixed point

Parameters

Expected hall sequence in positive direction — Sequence indicating positive direction

ABC (default) | CBA | Custom sequence

The Hall sensor sequence that represents the positive direction of rotor spin.

Sequence — Custom sequence indicating positive direction

[5,4,6,2,3,1] (default) | scalar

The custom sequence that you can enter to represent rotor spin in the positive direction.

Dependencies

To enable this parameter, set Expected hall sequence in positive direction to Custom sequence.

Counter size — Size of external counter register

16 bits (default) | 8 bits | 32 bits

The register size of the external counter. The maximum counter value is $${\text{2}}^{\text{n}}\text{-1}$$, where $$\text{n}$$ = counter size.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Fixed-Point Conversion
Design and simulate fixed-point systems using Fixed-Point Designer™.

Version History

Introduced in R2020a