Low speed and high speed estimates of rotor angle and speed relative to the stator are received from a low speed estimator and a high speed estimator, respectively. LS_θ_EST and a subset of torque-controlling I_Q trajectory curve (“IQTC”) parameter values appropriate to low speed rotor operation are selected for rotor speeds below a low speed threshold value ω_LOW_THRS. HS_θ_EST and a subset of IQTC curve parameter values appropriate to high speed rotor operation are selected for rotor speeds above a high speed threshold value ω_HIGH_THRS. LS_θ_EST and the low speed subset of IQTC parameter values remain selected for rotor speeds less than ω_HIGH_THRS after accelerating to a rotor speed greater than ω_LOW_THRS. HS_θ_EST and the subset of high speed IQTC parameter values remain selected for rotor speeds greater than ω_LOW_THRS after decelerating to a rotor speed less than ω_HIGH_THRS.

A method for determining a position of a rotor of a brushless direct current (BLDC) motor at standstill. The method includes providing a plurality of current pulses to a plurality of windings of the BLDC motor while the rotor of the BLDC motor is at a standstill position. The method further includes measuring a plurality of times that it takes for the plurality of current pulses to reach a threshold for respective ones of the plurality of windings. A first position corresponding to a shortest time of the plurality of times is determined. A position detection value is determined based on the shortest time and based on times corresponding to positions that are adjacent to the first position. A position of the rotor at the standstill position is determined based on the position detection value and an interpolation function.

A method of determining a position of a rotor of a brushless permanent magnet motor includes measuring phase current flowing through a phase winding of the motor during excitation of the phase winding, and measuring voltage applied to the phase winding of the motor during excitation of the phase winding. The method includes calculating a phase of back EMF induced in the phase winding using the measured phase current and the measured voltage. The method includes determining a zero-crossing point of the back EMF induced in the phase winding using the calculated phase of back EMF induced in the phase winding. The method includes determining an aligned position of the rotor of the brushless permanent magnet motor when the back EMF induced in the phase winding is at the zero-crossing point.

A method for ascertaining, without an encoder, a rotational angle position of the rotor of a brushless DC motor, includes the steps of: detecting a voltage induced in a stator of the brushless DC motor; checking whether the voltage induced in the stator is lower than a threshold value; and if the induced voltage is lower than the threshold value, then ascertaining an initial rotational angle position of the rotor based on an Indirect Flux detection by Online Reactance Measurement, and subsequently updating the rotational angle position proceeding from the calculated initial rotational angle position using at least one continuous test signal.

A method for operating a brushless direct current motor wherein, by the energization of a plurality of armature coils which are arranged on a stator and form a three-phase current winding for generating a rotating field which rotates around the stator, and having three terminals, a rotating field is generated in order to drive a rotor, which is rotatable about an axis of rotation relative to the stator and has at least two opposing permanent magnet poles. For the determination of the position of the rotor relative to the stator a measurement voltage signal is applied between a first and second of the terminals, a resulting voltage is measured on a third of the terminals, a gradient value which indicates the gradient of the resulting voltage in a time interval is determined with reference to the progression over time of the resulting voltage.

A motor controller includes a square wave voltage generator and adding circuitry for adding the square wave voltage to a first drive voltage that is connectable to the stator windings of a motor. A current monitor for monitoring the input current to the motor as a result of the square wave voltage. A device for determining the position of the rotor based on the input current.

A method of smoothly starting a Hall-less motor includes the steps of applying voltage to two items of a three-phase motor, determining positioning duty and positioning time so that duty cycle progressively increases from zero to prevent jitter during positioning, using fixed duty cycle so that dragging duty cycle equals to positioning duty cycle, setting initial phase-changing time and phase-changing time when dragging is ended, changing phase after timer is interrupted, generating logic signal by three-phase signal generated by three-phase motor, and transmitting to central processor simultaneously using external interruption method. The method adopts low cost hardware circuit structure, optimizes starting algorithm, and simplifies product design. Algorithm optimization is carried out in every step, and it has the advantages of smooth starting process, short starting time, and almost zero starting failure rate.

The present relates to a sensorless driving apparatus and a sensorless driving method for a brushless motor. In a state that the brushless motor is driven by rectangular waves, when the driving apparatus detects that a rotation speed of the brushless motor becomes higher than a predetermined speed and thereafter it detects that an angle of a rotor of the brushless motor becomes a predetermined angle, the driving apparatus switches the drive from rectangular wave drive to sign wave drive. The driving apparatus sets as the predetermined angle an angle at which energizing mode is switched in the rectangular wave drive or an angle at which a motor torque is at a peak value in the rectangular wave drive.

Low speed and high speed estimates of rotor angle and speed (LS_θ_EST/LS_ω_EST and HS_θ_EST/HS_ω_EST) relative to the stator are received from a low speed estimator and a high speed estimator, respectively. LS_θ_EST and a subset of torque-controlling I_Q trajectory curve (“IQTC”) parameter values appropriate to low speed rotor operation are selected for rotor speeds below a low speed threshold value ω_LOW_THRS. HS_θ_EST and a subset of IQTC curve parameter values appropriate to high speed rotor operation are selected for rotor speeds above a high speed threshold value ω_HIGH_THRS. LS_θ_EST and the low speed subset of IQTC parameter values remain selected for rotor speeds less than ω_HIGH_THRS after accelerating to a rotor speed greater than ω_LOW_THRS. HS_θ_EST and the subset of high speed IQTC parameter values remain selected for rotor speeds greater than ω_LOW_THRS after decelerating to a rotor speed less than ω_HIGH_THRS. Hysteresis in the selection of θ_EST and IQTC parameter values results in smooth acceleration/deceleration control.

The present invention relates to a rideable saddle vehicle (200) comprising: an electric traction motor (1) which includes a stator and rotor; a first vehicle speed measurement sensor configured to generate a first signal (6.1) which is characteristic of the vehicle speed; a control system of the vehicle comprising; a first unit (2) for supplying and controlling said electric motor (1), wherein said first unit (2) supplies and controls said electric motor (1) on the basis of a control signal (5.1), said control signal (5.1) being characteristic of the torque required to said electric motor (1); a computing unit (20) configured to generate a second signal (7.1) which is characteristic of the speed of the vehicle, wherein said computing unit (20) comprises first computing means (4) configured to calculate the angular position of said rotor with respect to said stator on the basis of the counter-electromotive force produced by said electric motor (1), and wherein said second signal (7.1) is generated on the basis of the value of said position calculated by said computing means (4); wherein said control signal (5.1) is generated on the basis of a torque signal (8) and on the basis of said first signal (6.1) and/or said second signal (7.1) which are characteristic of the speed of said vehicle.