Jtekt Corporation

Hiroshi Sumasu

Shigeki Nagase

Takeshi Ueda

Yuji Kariatsumari

Nobuhiro Uchida

Motoo Nakai

Koichiro Matsuhisa

Ryohei Shigeta

Hiroshi Kitamoto

Kouya Yoshida

Noboru Niguchi

Shigekazu Okumura

Yuta Iwai

Mayuko Wakida

Fumihiko Satou

Kohji Kimura

A microcomputer includes a current command value setting unit configured to set a two-phase current command value in a two-phase rotating coordinate system for each of PWM cycles in a current control cycle, and an open-loop control unit configured to calculate a two-phase voltage command value for each of the PWM cycles, according to a motor voltage equation, based on the two-phase current command value for each of the PWM cycles that is set by the current command value setting unit and a rotation speed of an electric motor. The two-phase voltage command value is a command value of voltage that is to be applied to the electric motor.

Motor control device

A motor control device includes: a noise reduction unit that sets a PWM count in units of PWM cycles for each PWM cycle in a current control cycle such that a current that flows through a frame ground because of a phase voltage for any one of three phases is canceled out with a current that flows through the frame ground because of a phase voltage for one of the two other phases in each PWM cycle in the current control cycle; and a noise canceling circuit configured to generate a current that is opposite in phase to a current that flows through the frame ground because of a phase voltage for the other of the two other phases in each PWM cycle in the current control cycle.

A motor controller includes a motor drive circuit, a noise cancellation circuit, and a control unit. The motor drive circuit supplies electric power to an electric motor. The noise cancellation circuit includes an RLC circuit, a switch element, and a pull-down resistor. One end of the RLC circuit is electrically connected to a positive terminal of a power supply via the switch element, and the other end of the RLC circuit is electrically connected to a frame ground. A connection point between the RLC circuit and the switch element is electrically connected to a negative terminal of the power supply via the pull-down resistor. The control unit turns ON the switch element for a predetermined time at falling timings of phase voltages output from the motor drive circuit.

Motor controller

An electric motor that is controlled by a motor control device has two-system multi-phase motor coils. The motor control device includes a common mode noise reduction unit that changes a PWM count in a PWM cycle for at least one phase in one of two systems such that a current that flows through a stray capacitance because of an output voltage for one phase in the other system is canceled out with a current that flows through the stray capacitance because of an output voltage for the at least one phase in the one system in at least one PWM cycle in a current control cycle.

A motor control unit includes a PWM count calculator, a PWM count setter, and a PWM count changer. The PWM count calculator calculates first PWM counts of phases. Each first PWM count is calculated for a current control period. The PWM count setter sets the first PWM count of each phase as a second PWM count of a corresponding phase. The second PWM count is set for each of PWM periods included in the current control period. The PWM count changer changes the second PWM count of at least one of the phases, without changing the total of the second PWM counts of the at least one phase within the current control period, such that the number of times switching elements corresponding to the at least one phase are switched within the current control period is reduced.

Motor control unit

A first PWM count computation unit computes a first PWM count for each of three phases in a first system. A second PWM count computation unit computes a second PWM count for each of three phases in a second system. Upper and lower switching elements for each phase in the first system are controlled in accordance with a first pattern in which the upper and lower switching elements are varied in the order of an upper on state, a lower on state, and the upper on state from the time of start of PWM cycles. Upper and lower switching elements for each phase in the second system are controlled in accordance with a second pattern in which the upper and lower switching elements are varied in the order of a lower on state, an upper on state, and the lower on state from the time of start of PWM cycles.

An auxiliary drive device includes: a drive unit that has an electric motor; a meshing clutch that has a first meshing member and a second meshing member; an actuator that moves the second meshing member; and a control unit that controls the electric motor and the actuator. The actuator moves the second meshing member among a separation position, at which the second meshing member is not meshed with the first meshing member, an abutment position, at which first meshing teeth and second meshing teeth possibly abut against each other, and a meshing position, at which the first meshing teeth and the second meshing teeth are meshed with each other. The control unit makes a current supplied to the electric motor when the second meshing member is located between the abutment position and the meshing position smaller than a current required to maintain the rotational speed of the electric motor.

Auxiliary drive device

A motor control device includes: a PWM count computation unit that computes a PWM count for each of three phases for each current control cycle; a PWM count setting unit that sets the PWM count for each phase in the current control cycle as a PWM count for each PWM cycle in the relevant current control cycle for the corresponding phase; and a common mode noise reduction unit that changes the PWM count in a PWM cycle for at least one phase, of two of the three phases other than one particular phase, such that a current that flows through a stray capacitance because of an output voltage for the one particular phase is canceled out with a current flowing through the stray capacitance because of an output voltage for the at least one of the two other phases in at least one PWM cycle in the current control cycle.

A common mode noise reduction section performs a first noise reduction process in a first system, a second noise reduction process in a second system and a third noise reduction process in the case where the two systems have a phase, a current for which that flows through a stray capacitance is not canceled out in at least one PWM cycle in a current control cycle after the first noise reduction process is performed and the second noise reduction process is performed. The third noise reduction process includes shifting a PWM count for each phase in the first system by a first predetermined amount and shifting a PWM count for each phase in the second system by a second predetermined amount such that the currents for such a phase which flow through the stray capacitances in the two systems cancel out each other in the relevant PWM cycle.

A motor control unit includes a PWM count changer that when, out of all possible combinations of any two of three phases, at least one of the combinations has a difference in PWM count less than a threshold value, changes a PWM count of at least one of the two phases of the at least one of the combinations for each of PWM periods within a current control period, without changing the total of the PWM counts of the at least one of the two phases within the current control period, such that each of the combinations has a difference in PWM count greater than or equal to the threshold value.

A maximum spectrum peak reduction unit sets a PWM count generated by a PWM duty ratio calculation unit for a specific current control period as PWM counts for respective PWM periods within the current control period, and changes the set PWM counts for the respective PWM periods within the current control period so that a frequency component having a frequency obtained by dividing a carrier frequency in half or less is included in a PWM signal waveform within the current control period without changing a total value of the PWM counts for the respective PWM periods.

A power circuit abnormality detection method for a power circuit detects whether an abnormality in a power source relay exists. The power circuit includes a pre-charge circuit opening and closing a connection between a direct current power source and a smoothing condenser by bypassing the power source relay to pre-charge the smoothing condenser, and a discharge circuit connected in parallel to the smoothing condenser to discharge electric charges stored in the smoothing condenser via a discharge resistance when a discharge switch is closed. The power circuit abnormality detection method includes a step of detecting whether the open contact abnormality in the power source relay exists based on whether a charge voltage of the smoothing condenser is reduced when a predetermined period of time has elapsed since both the discharge circuit and the power source relay are closed after the pre-charge circuit is opened.

Power circuit abnormality detection method

When one of six FETs has short-circuit faulted, a controllable region identification unit stops driving of an electric motor, and then performs processes for determining whether a short-circuit fault has occurred, and when a short-circuit fault has occurred, for identifying the position of the FET that has short-circuit faulted based on phase voltages (induced voltages) V, V, and Vof phases. When the position of the FET that has short-circuit faulted is identified, the controllable region identification unit performs a controllable region identification process. In detail, the controllable region identification unit identifies a 'possible region,' an 'indeterminate region,' and a &#x201c;impossible region&#x201d; based on phase voltages V, V, and Vof the phases.

A command current setting portion has a target value corrector that calculates d-axis and q-axis current command values idc, iqc that are to be supplied to an open-loop controller, based on d-axis and q-axis current target values id*, iq*. When d-axis and q-axis voltage target value vd*, vq* calculated from the d-axis and q-axis current target values id*, iq* by the motor circuit equations exceed a voltage limit, this target value correctorcorrects the d-axis and q-axis current target values id*, iq* by the field weakening control such that d-axis and q-axis voltages vd, vq and d-axis and q-axis currents id, iq satisfy &#x221a;(vd+vq)&#x2266;Vlim and &#x221a;(id+iq)&#x2266;Ilim respectively. The d-axis and q-axis current command values idc, iqc are obtained by this correction.

Motor controller and electronic power steering apparatus

A multilayer circuit substrate includes: a laminated circuit portion in which conductive layers and resin insulating layers are alternately laminated; and a metal substrate portion, wherein the laminated circuit portion is fixed to the metal substrate portion so that at least part of a lower surface of the laminated circuit portion is in contact with at least part of an upper surface of the metal substrate portion. An electronic component is mounted on the metal substrate portion.

Growing community of inventors

Kashihara, Japan

Hiroshi Sumasu