Abstract: In a sensorless control of a motor, due to the characteristic of a response frequency, an induced voltage, a magnetic pole position estimation gain, a current control gain, and a speed control gain are closely related. An object of the invention is to enable the induced voltage and the frequency characteristic of a magnetic pole position estimation system to be clearly designed and to theoretically and quantitatively design all of the control gains necessary for the sensorless control so as to solve a problem that a method of designing those parameters cannot be established and the parameters have to be adjusted in a try and error manner. A control device has an estimator estimating an estimation induced voltage and a phase error of a motor by applying an induced-voltage observer and a controller controlling the motor on the basis of the estimation induced voltage and the phase error.

Abstract: The present invention provides a signal processor that improves a resolution of a phase detection without increasing a clock frequency of a controller or decreasing a frequency of an excitation signal. A signal processor 10 includes a comparator 11 that compares a signal obtained by phase modulating a carrier frequency at a rotor rotation angle of a resolver with a dither signal.

Abstract: In a sensorless control of a motor, due to the characteristic of a response frequency, an induced voltage, a magnetic pole position estimation gain, a current control gain, and a speed control gain are closely related. An object of the invention is to enable the induced voltage and the frequency characteristic of a magnetic pole position estimation system to be clearly designed and to theoretically and quantitatively design all of the control gains necessary for the sensorless control so as to solve a problem that a method of designing those parameters cannot be established and the parameters have to be adjusted in a try and error manner. A control device has an estimator estimating an estimation induced voltage and a phase error of a motor by applying an induced-voltage observer and a controller controlling the motor on the basis of the estimation induced voltage and the phase error.

Abstract: Provided is a control system for a work vehicle having a work implement, the control system including: a position measurement unit for measuring a position of a windrow produced by grading work; a work route setting unit for setting a work route based on the position of the windrow that has been measured by the position measurement unit; and a travel control unit for controlling the work vehicle to travel along the work route that has been set by the work route setting unit.

Abstract: A method of controlling a motor grader including a blade provided between a front wheel and a rear wheel which are attached to a vehicular body and a height adjustment mechanism which adjusts a height of the blade includes obtaining current topography in front of the motor grader and adjusting a height of the blade with respect to the front wheel based on the current topography.

Abstract: A control method is performed in a motor grader, the motor grader including a blade between a front wheel and a rear wheel, the blade being attached to a swing circle which adjusts a blade angle. The control method includes detecting a load applied to the blade and revolving, when the detected load is larger in value than a predetermined reference value, the swing circle in such a direction that the blade angle is smaller than the blade angle at the time of detection of that value.

Abstract: A work vehicle capable of accurately obtaining current topography to be worked is provided. A motor grader includes a vehicular body frame, a blade, and a camera. The blade is arranged between a front end of the vehicular body frame and a rear end of the vehicular body frame. The camera is configured to obtain current topography in front of the vehicular body frame. The camera is attached to the vehicular body frame. The camera is arranged in front of the blade.

Abstract: A motor grader includes a blade between a front wheel and a rear wheel, the blade being attached to a swing circle which adjusts a blade angle. A control method performed in the motor grader includes obtaining current topography in front of the motor grader and adjusting the blade angle to an angle in accordance with the current topography by revolving the swing circle.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Abstract: A control apparatus includes, for at least two-phase signals detected from a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, a signal generator that generates a correction signal for canceling out an error component of the carrier signal, and a synthesizer that synthesizes the phase-shifted first phase signal, the phase-shifted second signal, and the correction signal for canceling out the error component, in order to create a phase-modulated signal that is the carrier signal being modulated at a rotation angle of a rotor of the resolver.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Abstract: In a sensorless control of a motor, due to the characteristic of a response frequency, an induced voltage, a magnetic pole position estimation gain, a current control gain, and a speed control gain are closely related. An object of the invention is to enable the induced voltage and the frequency characteristic of a magnetic pole position estimation system to be clearly designed and to theoretically and quantitatively design all of the control gains necessary for the sensorless control so as to solve a problem that a method of designing those parameters cannot be established and the parameters have to be adjusted in a try and error manner. A control device has an estimator estimating an estimation induced voltage and a phase error of a motor by applying an induced-voltage observer and a controller controlling the motor on the basis of the estimation induced voltage and the phase error.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Abstract: A control apparatus includes, for at least two-phase signals detected from a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, a signal generator that generates a correction signal for canceling out an error component of the carrier signal, and a synthesizer that synthesizes the phase-shifted first phase signal, the phase-shifted second signal, and the correction signal for canceling out the error component, in order to create a phase-modulated signal that is the carrier signal being modulated at a rotation angle of a rotor of the resolver.

Abstract: The present invention provides a signal processor that improves a resolution of a phase detection without increasing a clock frequency of a controller or decreasing a frequency of an excitation signal. A signal processor 10 includes a comparator 11 that compares a signal obtained by phase modulating a carrier frequency at a rotor rotation angle of a resolver with a dither signal.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.

Abstract: A circle rotator of a motor grader includes a worm, a worm wheel and a shaft. The worm wheel has an inner peripheral portion, an outer peripheral portion enclosing the inner peripheral portion from outside, and a plurality of first clutch discs to be spline-coupled to the inner peripheral surface of the inner peripheral portion. The inner peripheral portion is made of a material harder than a material of which the outer peripheral portion is made.

Abstract: A signal converter 100 includes, for at least two-phase signals detected by a resolver excited by a carrier signal having a carrier frequency fc, a first phase shifter 101 that shifts a phase of a first phase signal of the resolver with a pole at a frequency f1 lower than the carrier frequency fc, a second phase shifter 102 that shifts a phase of a second phase signal of the resolver with a pole at a frequency f2 higher than the carrier frequency fc, and a synthesizer 103 that combines the phase-shifted first phase signal with the phase-shifted second phase signal.