Abstract: An air pressure information display device of a vehicle tire has a normal air pressure storage module (10a) for storing a normal air pressure of a tire corresponding to a tire temperature, an excessive/deficient amount detection module (10b) for detecting the excessive/deficient amount from the normal air pressure on the basis of the stored normal air pressure, and air pressure information detected by an air pressure information detection module (6-9), and a display control module (10c) for controlling a display (11) to display the detected excessive/deficient amount. Hence, since the user is informed of the excessive/deficient amount from the normal air pressure, he or she can appropriately determine an air pressure state of a tire even when he or she does not recognize the normal air pressure.

Abstract: A server for changing control gains of a vehicle is disclosed. The server includes a first receiver for receiving environment data obtained by vehicles of a plurality of users running in specific areas, and a second receiver for receiving learned data obtained by a plurality of users operating vehicles, and a storage device for accumulating the environment data and the learned data. The server further includes a transmitter for fetching environment data and learned data necessary to produce control gains from among the accumulated environment data and the learned data and transmitting the fetched environment data and learned data to a user requesting the environment data and the learned data. In a vehicle of the user, the control gains are newly produced and previously produced control gains are changed to the newly produced ones.

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 motor drive system without any portion for directly detecting the rotor position, rotation speed and motor phase currents, capable of realizing a high-performance variable speed drive even at high carrier frequencies. When detecting a current from a DC power supply of an inverter for driving a motor, applied voltages and frequencies to the motor are controlled based on sampled values by sampling a current flowing as intermittent pulses in the vicinity of each power conduction time period.

Abstract: An electric motor driving system has a permanent magnet type synchronous motor, an inverter for driving the motor, a generator for issuing a rotational frequency command to the motor and a controller including a conversion gain for generating a control signal to the inverter on the basis of the rotational frequency command, an integrator, a zero generator, a qc-axis voltage command arithmetic unit, a dq inverter, a dq coordinate converter, a high-pass filter, and an adder, wherein the system includes the high-pass filter for correcting the rotational frequency command to the motor on the basis of current detection values flowing through the motor, and a step-out detector for comparing the correction amount with a threshold value previously set for the coordinate amount to judge when the correction amount exceeds the threshold value at least one or more times that the motor is in the step-out state.

Abstract: A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: In order to provide a driving device for a motor having a capability equivalent to conventional vector control type sensorless method by simplifying the controls structure to reduce number of parts to be adjusted, and to stabilize the control system, a driving device for a synchronous motor does not include a speed controller or a current controller, and calculates a voltage impressed on a motor on coordinate axes (dc/qc axes) based on a magnetic pole axis. For calculating a voltage command, command values such as a rotation speed command and a current command are used, and Iq* corresponding to a torque current command is calculated and provided based on a detected current value.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: An air pressure warning device of a vehicle tire has an excessive/deficient amount calculation module (10b) for calculating an excessive/deficient amount on the basis of the difference between a normal air pressure stored in a normal air pressure storage module (10a) and a detected tire air pressure, an informing control module (10c) for controlling an informing module (11) to inform an excessive/deficient state of the tire air pressure determined based on the calculated excessive/deficient amount, and a normal air pressure correction module 10e for increasing the readout normal air pressure by a predetermined value when an expressway traveling detection module (10d) detects that the vehicle is on an expressway.

Abstract: An electric power steering system determines an assist control quantity for assist control by multiplying a turning torque applied to a steering wheel by a control gain, a damping control quantity for damping control by multiplying a rotational speed of motor by a control gain and a feedback control quantity for steering angle feedback control from a deviation between a target rotational speed of motor determined on the basis of the turning torque and an actual rotational speed of motor, and controls an electric motor with a motor control quantity that is determined on the basis of the assist control quantity, the damping control quantity and the feedback control quantity.

Abstract: In an air pressure information display system of a vehicle tire, a vehicle (1) has air pressure sensors (7-9) for detecting the air pressure of a vehicle tire (2-5), and transmitting air pressure information indicating the detected air pressure via a wireless communication, and an informing unit (100) installed in a gas station or the like has a display module (100b) for displaying the received air pressure information.

Abstract: An air pressure warning device of a vehicle tire has an excessive/deficient amount calculation module (10b) for calculating an excessive/deficient amount on the basis of the difference between a normal air pressure stored in a normal air pressure storage module (10a) and a detected tire air pressure, an informing control module (10c) for controlling an informing module (11) to inform an excessive/deficient state of the tire air pressure determined based on the calculated excessive/deficient amount, and a normal air pressure correction module 10e for increasing the readout normal air pressure by a predetermined value when an expressway traveling detection module (10d) detects that the vehicle is on an expressway.

Abstract: An air pressure information display device of a vehicle tire has a normal air pressure storage module (10a) for storing a normal air pressure of a tire corresponding to a tire temperature, an excessive/deficient amount detection module (10b) for detecting the excessive/deficient amount from the normal air pressure on the basis of the stored normal air pressure, and air pressure information detected by an air pressure information detection module (6-9), and a display control module (10c) for controlling a display (11) to display the detected excessive/deficient amount. Hence, since the user is informed of the excessive/deficient amount from the normal air pressure, he or she can appropriately determine an air pressure state of a tire even when he or she does not recognize the normal air pressure.

Abstract: In an electric power steering apparatus for a motor vehicle comprising a rack shaft (1) provided with first and second rack portions (14 and 15), a pinion (21) of a steering shaft for meshing with the first rack portion (14), and a pinion (31) of an electric motor (34) for meshing with the second rack portion (15), the first rack portion (14) is constructed to have a constant gear ratio and the second rack portion (15) is constructed to have a variable ratio so that an abnormal feeling during a steering operation is prevented and the lock to lock of a steering wheel is reduced to a small value.

Abstract: An electric motor driving system has a permanent magnet type synchronous motor, an inverter for driving the motor, a generator for issuing a rotational frequency command to the motor and a controller including a conversion gain for generating a control signal to the inverter on the basis of the rotational frequency command, an integrator, a zero generator, a qc-axis voltage command arithmetic unit, a dq inverter, a dq coordinate converter, a high-pass filter, and an adder, wherein the system includes the high-pass filter for correcting the rotational frequency command to the motor on the basis of current detection values flowing through the motor, and a step-out detector for comparing the correction amount with a threshold value previously set for the coordinate amount to judge when the correction amount exceeds the threshold value at least one or more times that the motor is in the step-out state.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: A server for changing control gains of a vehicle is disclosed. The server includes a first receiver for receiving environment data obtained by vehicles of a plurality of users running in specific areas, and a second receiver for receiving learned data obtained by a plurality of users operating vehicles, and a storage device for accumulating the environment data and the learned data. The server further includes a transmitter for fetching environment data and learned data necessary to produce control gains from among the accumulated environment data and the learned data and transmitting the fetched environment data and learned data to a user requesting the environment data and the learned data. In a vehicle of the user, the control gains are newly produced and previously produced control gains are changed to the newly produced ones.

Abstract: A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.