Abstract: A method and control system to control a brushless DC motor to a preferred position is provided. The advantages that accrue to a system employing the method and apparatus to control the brushless DC motor to a preferred position include optimizing response time, energy usage, coil heating, and ability to hold to a fix position. The method to control the brushless DC motor to a position comprises monitoring actual position of the brushless DC motor, monitoring energy used by the brushless DC motor, and determining a commanded position of the brushless DC motor. A zero torque commutation method is employed to control the brushless DC motor to the commanded position only when a time-rate change in the commanded position is less than a first threshold, a difference between the commanded position and actual position is less than a second threshold, and, the monitored energy used is less than a third threshold.

Abstract: It is an object of the invention to provide a technique to effectively prevent a power tool from being adversely affected when a battery is removed from the power tool. According to the present invention, a power tool is provided that includes a tool bit, a motor that drives the tool bit, a body that houses the motor, a battery detachably coupled to the body so as to supply driving current to operate the motor, a control device that controls the operation of the motor and a power circuit that leads the driving current from the battery to the motor. Within the power tool, the control device stops the motor prior to an interruption of the power circuit when the battery is disengaged from the body in order to prevent a large driving current from being passed through the power circuit. As a result, arc can be effectively prevented from being generated between the battery and the body of the power tool.

Abstract: An electric machine assembly having an electric machine. The electric machine can include a first speed circuit and a second speed circuit. In some constructions, both speed circuits can be of a permanent split capacitor design. At least one of the speed circuits can include a switch that is controlled by the controller to limit current through an auxiliary circuit of the unused speed circuit when certain conditions exist.

Abstract: A servo motor with a built-in drive circuit is provided in which, when power is off, positional data including multiple-rotation counting values is stored in a nonvolatile memory to thereby eliminate battery back-up, and in which the CPU of a drive control circuit portion is in charge of the multiple-rotation counting itself to thereby eliminate the circuit for multiple-rotation counting. Due to a reduction in the number of lines involved and an elimination of battery back-up, a reduction in size is achieved. The servo motor with a built-in drive circuit includes an absolute encoder for detecting rotation of a servo motor portion and an electromagnetic mechanical brake, in which, when the power is off, the positional data at that time is stored in a nonvolatile memory.

Abstract: A temperature sensor (33) detects the temperature of a MOS transistor (7), and a current detecting circuit (35) detects current flowing in the MOS transistor (7). When the voltage corresponding to the detected temperature or the voltage corresponding to the detected current is increased to a threshold value or more, an overheat state detecting signal and further switching signal is set to a high level. As a result, a switch circuit in a driving circuit (17) is turned on, and the gate resistance value becomes the parallel value of a resistor (25), and the PWM frequency in the PWM control circuit is lowered, whereby the switching loss of the MOS transistor (7) can be reduced under the state that the motor (2) is rotated.

Abstract: A system for control of a plurality of motors comprising: an inverter including at least three legs, with each leg including two series switching devices configured to receive a command from a controller. The system also includes a first motor operably connected to an inverter at a common terminal of the switching devices for a first leg and at a common terminal of the switching devices for a second leg; a second motor is operably connected to the inverter at the common terminal of the switching devices for the second leg and at a common terminal of the switching devices for a third leg. The outer terminals of the switching devices for each of the first leg, second leg and third leg are operably connected to the voltage source. The controller executes a process for controlling the first motor and the second motor with an error arbiter function.

Abstract: An AC motor control apparatus that is applicable to commonly used PM motors and capable of detecting the magnetic pole position with simple algorithm. The AC motor control apparatus comprises an inverter for applying arbitrary AC power to an AC motor and a controller for sending a control signal to the inverter. The controller comprises a ripple current generator for supplying a ripple current to the AC motor and a magnetic pole position estimator. The magnetic pole position estimator observes at least two current values of the ripple current for both positive and negative sides of the ripple current to estimate the magnetic pole position of the AC motor.

Abstract: A method of controlling the torque of a multiphase induction motor includes the step of energizing the stator windings of the motor from a power converter using thyristors, inserted between a multiphase main supply and the windings producing a stator current set point expressed by its amplitude and its phase, predicting phase coincidences between the stator current and the set point, and commanding the power converteer so that the windings receive current waves substantially when such coincidences occur.

Abstract: A control system for an electric machine includes a flux weakening module, which includes a voltage magnitude calculator that receives d-axis and q-axis command voltages and that generates a voltage magnitude. An error circuit compares the voltage magnitude to a reference voltage and generates an error signal. A controller receives the error signal and generates a feedback flux correction signal. A limiter limits the feedback flux correction signal to a predetermined flux value and generates a limited feedback flux correction signal. A feedforward stator flux generating circuit generates a feedforward stator flux signal. A summing circuit sums the feedforward stator flux signal and the limited feedback flux correction signal to generate a final stator flux command.

Abstract: A hybrid drive apparatus includes an engine, a first electric motor for generating electric power by using at least a portion of its output and for controlling the speed of the engine and a control unit for controlling the engine and the first electric motor. The control unit performs a prepositioning control for positioning the engine being fuel-cut to a predetermined cranking start position such as a constant crank angle position or a constant cranking load position by the motoring of the first electric motor. As a result, the engine can always be started under identical conditions, and the torque vibrations to be outputted to a wheel have identical waveforms so that a simple torque correction can be made by outputting corresponding waveform data.

Abstract: A method for changing the speed of a motor group, in particular for starting or stopping it, the motor group comprising a plurality of squirrel-cage induction motors or synchronous motors and network converters arranged for their control, when the nominal supply power (Pns), the acceleration power (Pacct) at the final speed (Vmax) of the motors and the losses (Ploss) of the used power are known.

Abstract: A servo control device comprises a current supply unit for supplying a drive unit with a drive current for driving a target to be controlled, a first detector for detecting at least the drive current value, and a logical arithmetic section. The logical arithmetic section introduces a current command determining the drive current for controlling the drive speed of the drive unit to move the target to a predetermined position, and introduces the drive current value fed back from the first detector. The logical arithmetic section outputs the current command to the current supply unit after converting the current command by a digital logic process on the basis of the drive current value by using a custom LSI.

Abstract: The position and speed and, in some embodiments, direction of rotation of a motor for turning the rod of an object such as a window covering is determined by placing a braking magnet next to the motor and a piezoelectric element between the braking magnet and motor. As the motor rotates, the piezoelectric element generates a signal that can be used to determine the speed of rotation and also the position of the motor (and, hence, the position of the object being moved). The magnet brakes the motor from turning under the weight of the object when the motor is deenergized.

Abstract: A system and method of motor control enable improved motor control by controlling a phase winding to float or enter a high impedance state prior to activating phase detection of the phase winding. Because the phase winding floats prior to phase detection, the effect residual current coupling in such phase can be mitigated and thereby help improve motor operation.

Abstract: The present invention discloses a robotic manipulator, comprising at least one joint, each joint having a drive axis and at least one microelectromechanical system (MEMS) inertial sensor aligned with at least one drive axis providing sensing of a relative position of the drive axis. The robotic manipulator can include an inertial measurement unit (IMU) coupled to the robotic manipulator for determining the end effector position and orientation. A controller can be used, receiving a signal from at least one MEMS inertial sensor and controlling at least one joint drive axis in response to the signal to change the relative position of the joint drive axis. Rate information from MEMS sensors can be integrated to determine the position of their respective drive axes.

Abstract: A region judging circuit judges an electric angle region of a three-phase brushless DC motor based on an output signal of a resolver. A latch timing output circuit determines an optimum latch timing. A driving direction judging circuit judges a rotational direction of the motor based on a comparison in largeness between a pair of phase currents. A latch circuit latches a judgement result of the driving direction judging circuit at the latch timing designated by the latch timing output circuit and retains the judgement result until the next latch timing comes.

Abstract: In a foot of a legged mobile robot, deformation of the foot is absorbed by a first concavity and the position and shape of a ground-contact portion hardly change. Accordingly, variation in a resistive force against the moment about the yaw axis can be reduced and a spinning motion can be prevented. In addition, when the foot is placed on a bump or a step, a flexible portion deforms and receives it, and a frictional retaining force is generated between the flexible portion and the bump. Thus, the foot is flexibly adapted to the road surface, and sliding caused by the bump and excessively fast motion are prevented. Accordingly, the foot can be adapted to various kinds of road surfaces such as surfaces having bumps and depressions, and the attitude stability can be increased.

Abstract: A dual stage drive for a switched reluctance motor (SRM) is disclosed, the SRM having a plurality of phase coils associated therewith. In an exemplary embodiment, the dual stage drive includes at least one of the plurality of phase coils coupled to a first power bus, and at least another one of the plurality of phase coils coupled to a second power bus. Energy within the at least one phase coil coupled to said first power bus is dissipated through said second power bus.

Abstract: A steering controlling device comprising a power source, a motor connected to a steering system, a motor driving circuit converting a power source voltage to a predetermined voltage and applying the voltage to the motor, and a controlling means for controlling the motor driving circuit, wherein the controlling means controls the motor driving circuit so as to boost the power source voltage when a rotational speed of the motor is a predetermined value or more, whereby a sufficient motor output torque is obtainable under various steering conditions in use of a converter, an efficiency is improved by suppressing a frequency of operating the converter, and an appropriate fail safe treatment is conducted when the converter is disordered.

Abstract: In a motor control device controlling a motor by a state feedback control, high control accuracy is maintained regardless of fluctuations in a motor load so as to improve control performance of the state feedback control. A control signal (manipulation amount) outputted from a feedback calculator for controlling the motor is compared to a manipulation threshold set to a manipulation threshold setting register so as to determine the magnitude of a load amount of the motor. The feedback calculator includes an observer and performs the state feedback control of the motor. When the load amount is in normal level, a normal load observer matrix set in an observer table is selected to configure a normal load observer. When the load amount is increased, a high load observer matrix is selected to configure a high load observer.