Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Katsuhiko Ohmae

Takayuki Kifuku

Takashi Furui

Yukihiro Okimoto

Hiroshi Nishimura

Shigeki Ohtagaki

Yuji Takatsuka

Susumu Zeniya

Norihiro Yamaguchi

Masaki Matsushita

Munenori Yamamoto

Hideki Doi

Kazuo Kikuta

Osamu Fujita

An objective is to detect a resolver malfunction without fail, using a low-cost resolver having the small number of the poles, and a control-motor system having advantage in small sizing and high-power outputting. In the control-motor system, the system for driving a 2m-pole motor based on a rotor rotation angle &#x3b8; detected by a 2n-pole resolver, where m and n being counting numbers, is characterized in that: the sum of the square of a signal modulated by sin &#x3b8; and the square of a signal modulated by cos &#x3b8; in the resolver in which an excitation signal generated in said system is modulated by sin &#x3b8; and cos &#x3b8; in response to the rotor rotation angle &#x3b8; of the resolver is compared to a predetermined malfunction threshold value, so that malfunction determination related to the resolver is performed, and also, given that the sum is awhen the resolver is recognized to be in normal operation, the malfunction determination threshold value is made to be not smaller than {a&#xd7;cos((&#x3c0;/2)/(m/n))}.

Control-motor system

A control device of a motor used in, for example, electric power steering control of a vehicle has to monitor the operation thereof to execute such a processing as stopping the control without delay upon detection of error. However, conventional monitoring devices have a disadvantage of taking a long time period the detection or not being able to detect an error of no output. A three-phase inverter circuithaving a substantially constant operation period is employed. The inverteroutputs an output waveform also at the moment of not driving the motor. An inverter period monitoring circuitis provided to monitor a period of the output waveform. When the period comes to be too large or too small as compared with a carrier period of the inverter, an alarm is outputted, and control of the inverter is stopped.

Motor control device

Conventionally, there was a problem that in cases when it is difficult to place a temperature sensor in the vicinity of a heat-generating portion, overheating could not be prevented. Disclosed is an electric power steering control system including a torque sensor for detecting steering force of a steering system; a motor current determination unit for determining the motor current based on the steering force detected by the torque sensor; a temperature sensor for detecting an ambient temperature; a coefficient setting unit for setting a coefficient in accordance with the detected temperature obtained by means of the temperature sensor; a motor current detection unit for detecting a motor current being passed to a motor; a maximum current limit value calculation unit for calculating a maximum current limit value based on the detected current and the coefficient; a current limiting unit for selecting the smaller value between the motor current determined by the motor current determination unit and the maximum current limit value calculated and outputting this as a target current; and a motor current control section for passing the target current to the motor in such a way that the motor current is equal to the detected current, whereby a motor current limit being set according to temperature is applied.

Electric power steering control system

A steering control device is realized which is capable of handling a variety of torque sensors through the same signal processing circuit, and in which a cost increase is suppressed while taking sufficient failsafe measures, having a torque sensor for detecting a signal corresponding to a steering torque in a steering system; a first microcontroller for outputting a steering torque signal equivalent to the steering torque; a second microcontroller for controlling an actuator based on the steering torque signal outputted; actuator driving means for driving the actuator controlling the steering system; and storage means in which a steering torque neutral point compensation data is stored in advance; wherein the first microcontroller compensates a neutral point of the steering torque signal based on the neutral point compensation data stored in the storage means.

Steering control device

In the prior art electric power steering controller, if it is restarted immediately after being turned off, melting and welding of a contact of a relay are detected while a smoothing capacitor is not yet fully discharged. This may lead to a misdetection. A novel electric power steering controller has a relay contact voltage detection circuit and a discharging circuit. The relay contact voltage detection circuit is located between the battery of a vehicle and an electric motor to give an assisting torque to a steering wheel and acts to detect the voltage at the contact of a relay on the side of the electric motor, the relay controlling the output from the battery. Then, melting and welding of the relay contact are detected, based on the voltage at the relay contact detected by the relay contact voltage detection circuit.

Electric power steering controller

An electric power steering device constructed to detect a steering force by a driver and a vehicle speed respectively by a torque sensor and a vehicle speed sensor, set a steering force assisting current for a motor by a steering force assisting current setter using the detected steering force and the detected vehicle speed, set an upper limit value of a motor current by a motor current upper limit value setter based on a power function of a deviation between the set steering force assisting current and a predetermined motor current reference value, and perform overheat protection by setting an upper limit of a motor current applied by a motor driving circuit based on an integrated value of the motor current squared, whereby a problem of an insufficient steering assisting force when stationary steering is repeated many times while parking in a garage in a narrow parking area is solved.

Electric power steering device

A starting apparatus of a passenger protecting apparatus is actuated by detecting collision of a vehicle. The starting apparatus is provided so as to subtract a predetermined value from an acceleration signal fed from G sensor and integrate the subtracted acceleration signal, and forcedly set an integrated value to zero if the integrated value is less than zero. Further, the starting apparatus is provided so as to provide a starting signal when the integrated value exceeds a preset threshold value. Therefore, it is possible to discriminate collision to start the apparatus from other collision, prevent starting means from being unnecessarily actuated, and avoid malfunction of the starting means.

Starting apparatus of passenger protecting apparatus and method thereof

An air bag activation device for a vehicle air bag system eliminates the need to feed a small test current during the standby state so that the power consumption is minimized, and detects faults of the air bag activating device accurately even if the battery voltage fluctuates, and prevents the air bag from expanding erroneously. The device bases the fault detection on the calculation of the difference between an amplified voltage when a small constant current is fed to the air bag activating device from a constant current circuit, and an amplified voltage in the absence of the current.

Fault detection method and apparatus for air bag activation device

Disclosed herein is a start control device for starting a vehicle passenger protecting device such as an air bag, which does not respond to an impact against which the vehicle passenger protecting device must not be started, but quickly responds to a collision against which the vehicle passenger protecting device must be started. The start control device includes a start level generator for setting a decision level of start signal generation to a higher level for a predetermined time from a rise timing of an acceleration signal obtained from an acceleration sensor in deciding a collision by using an integral value of the acceleration signal. With this arrangement, in case of the impact against which the vehicle passenger protecting device must not be started, the start signal can be prevented from being generated.

Start control device for vehicle passenger protecting device

Starting apparatus of passenger protecting apparatus

A Karman vortex flowmeter which comprises, in addition to a conventional vortex frequency detector for outputting an electrical signal including a vortex frequency signal component, a filter group consisting of a plurality of filters having a gradation of pass bands covering the variation range of the vortex frequency, and a waveform shaper circuit coupled to the output of the filter group for forming a pulse-shaped signal having a frequency equal to the vortex frequency. A filter in the filter group is selectively coupled to the shaper circuit in response to the output frequency thereof. The shaper circuit, on the other hand, holds the peak and the bottom level of the electrical signal; compares them with the positively and the negatively shifted electrical signal, respectively; and sets and resets a flip-flop when the peak and the bottom level cross with the positively and the negatively shifted electrical signal, respectively, the peak and the bottom level being reset after each occurrence of the crossing. The flip-flops outputs a pulse-shaped signal having the vortex frequency even if the electrical signal contains high and low frequency noise components.

Karman vortex flowmeter with signal waveform shaper circuit

A vortex flowmeter comprises a bank of filter sets (12) each for receiving a vortex signal produced according to the flow rate of a fluid to be measured, a waveform shaping circuit (13) for shaping an output of a selected one of the filter sets, a filter set switch decision circuit (14) for switching from one filter set to another by measuring the vortex frequency from an output of the waveform shaping circuit, and a switch circuit (15) responsive to a decision made by the filter set switch decision circuit to switch the filter set to thereby remove noise and beat components contained in the vortex signal.

Vortex flowmeter

A Karman vortex flowmeter is disclosed which comprises, in addition to a conventional vortex frequency detector means for outputting an electical signal including a vortex frequency signal component, a filter group consisting of a plurality of filters having a gradation of pass bands covering the variation range of the vortex frequency, and a waveform sharper circuit coupled to the output of the filter group for forming a pulse-shaped signal having a frequency equal to the vortex frequency. A filter in the filter group is selectively coupled to the shaper circuit in response to the output frequency thereof. The shaper circuit, on the other hand, holds the peak and the bottom level of the electrical signal; compares them with the positively and the negatively shifted electrical signal, respectively; and sets and resets a flip-flop when the peak and the bottom level cross with the positively and the negatively shifted electrical signal, respectively, the peak and the bottom level being reset after each occurence of the crossing. The flip-flop outputs a pulse-shaped signal having the vortex frequency even if the electrical signal contains high and low frequency noise components.

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Tokyo, Japan

Katsuhiko Ohmae