Patents by Inventor Masahira Akasu

Masahira Akasu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6563454
    Abstract: In an FM-CW radar apparatus, while a distance and velocity of a target are measured by simultaneously transmitting an FM modulation wave along a frequency-up direction and an FM modulation wave along a frequency-down direction toward this target, physically-required radar signal measuring time thereof can be reduced by ½.
    Type: Grant
    Filed: December 4, 2001
    Date of Patent: May 13, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Publication number: 20020190893
    Abstract: In an FM-CW radar apparatus, while a distance and velocity of a target are measured by simultaneously transmitting an FM modulation wave along a frequency-up direction and an FM modulation wave along a frequency-down direction toward this target, physically-required radar signal measuring time thereof can be reduced by ½.
    Type: Application
    Filed: December 4, 2001
    Publication date: December 19, 2002
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventor: Masahira Akasu
  • Patent number: 5959734
    Abstract: A distance measuring device having an improved control performance in a compact body by simplifying a structure for scanning a laser beam and a method of controlling the scanning. The device has a mirror for scanning an emitted laser beam, an axis around which the mirror is swung, a permanent magnet which swings along with the mirror, a core disposed opposite to the permanent magnet, a coil provided in the periphery of the core, a Hall element for detecting a swing angle of the mirror, and a circuit for controlling swing motion with a signal derived from a swing waveform formed in a predetermined shape in order to control a current in the coil, and a control signal formed by a controlled variable calculated from a deviation between a predetermined position of the mirror and a detected position.
    Type: Grant
    Filed: May 1, 1998
    Date of Patent: September 28, 1999
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Shoichi Tanaka, Yukio Fukushima, Masahira Akasu
  • Patent number: 5832407
    Abstract: A vehicle surrounding monitoring device including: a monitoring device for detecting objects present at a surrounding of a vehicle and outputting positions of the objects defined by a predetermined detection coordinate system; a coordinates transforming device having a calculation coordinate system in which a position of the monitoring device is an original point, a progressing direction of the vehicle is a first coordinate axis and an axis orthogonal to the first coordinate axis is a second coordinate axis for transforming the positions of the objects into positions defined by the calculation coordinate system; a vehicle speed detecting device for detecting a vehicle speed of the vehicle; a stationary object sampling means for sampling a plurality of stationary objects among the objects based on the vehicle speed; and an error detecting device for detecting a deviation of an optical axis of the monitoring device based on the vehicle speed, components of the first coordinate axis of the plurality of stationar
    Type: Grant
    Filed: July 23, 1996
    Date of Patent: November 3, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Koichi Kai, Masahira Akasu
  • Patent number: 5739901
    Abstract: A distance measuring apparatus for a vehicle including: an irradiating means for emitting and irradiating an electromagnetic wave; a receiving means for receiving a reflected wave produced when the electromagnetic wave is reflected by an obstacle and generating a receiving signal; a propagation delay time period measuring means provided with a comparison value set such that a value for a comparison reference is larger in a case in which a propagation delay time period from irradiating to receiving the electromagnetic wave is shorter than in a case in which the propagation delay time period thereof is longer for comparing the receiving signal with the comparison value, recognizing a time point at which the receiving signal is equal to or larger than the comparison value when the receiving signal is compared with the comparison value as a receive detecting time point and measuring the propagation delay time period from a time point at which the irradiating means irradiates the electromagnetic wave to the receiv
    Type: Grant
    Filed: October 13, 1995
    Date of Patent: April 14, 1998
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hiroshi Fujioka, Masahira Akasu, Shoichi Tanaka
  • Patent number: 5699151
    Abstract: A distance measurement device comprising a light-sending unit for sending pulsed light toward an object of measurement where a distance thereto is measured, a light-receiving unit for receiving incident light including pulsed reflection light reflected by the object, a distance measurement unit for measuring the time from the sending of the pulsed light to the receiving of the incident light and calculating the distance to the object, and an interference detection unit for determining whether interference light exists in the incident light, based on the intensity of the incident light.
    Type: Grant
    Filed: June 26, 1995
    Date of Patent: December 16, 1997
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 5552893
    Abstract: A distance measuring apparatus comprises projection means, light receiving means, computation means and scanning means. The projection means projects plural laser beams in different directions. The light receiving means receives the light reflected from each of objects in respective beam directions. The computation means computes the distances to the objects on the basis of the reflected light. And the scanning means sequentially changes the projecting directions of said plural laser beams.
    Type: Grant
    Filed: September 15, 1994
    Date of Patent: September 3, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 5504570
    Abstract: Disclosed is a distance measuring apparatus having a clock generating element, a light emitting element, a light receiving element, a sample pulse generating element, a sample hold element and a processing element. The clock generating element generates a clock pulse at a predetermined time interval. The light emitting element generates a pulse beam in synchronism with the clock pulse. The light receiving element receives a reflected pulse beam from an object and converts it into an electric signal. The sample pulse generating element generates a sample pulse at a timing delayed by a predetermined minute time from a generating time of the clock pulse within one measuring period. The sample hold element effects sampling of an output signal from the light receiving element with the sample pulse. The processing element calculates a distance to the object by detecting it from the output signal of the sample hold element and from the delay time of the sample pulse.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: April 2, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 5489149
    Abstract: An optical distance measurement apparatus for measuring the distance to an object 7 on the basis of the round-trip time of the light to and from the object. 7 includes an object detector means 32 and a smear detector means 33. The smear detector means 33 detects a smear when the ratio of unsuccessful measurements (i.e., the measurements by which no object is detected) is greater than or equal to a predetermined level. Alternatively, the number of successive measurements of a distance less than a predetermined threshold level (e.g., 50 meters) is stored in a counter, and the smear is detected when the content of the counter becomes greater than or equal to a predetermined number.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: February 6, 1996
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 5179286
    Abstract: A distance measuring apparatus for measuring a distance to an object of concern includes a clock pulse generator for generating a clock pulse signal at a predetermined frequency, a pulsed laser for emitting a light pulse to the object, a photodetection circuit for detecting an echo light pulse resulting from reflection of the light pulse at the object, an analogue-to-digital converter for converting an electric signal output from the photo-detection circuit to digital data under the timing of the clock pulse signal, and a memory for sequentially storing the digital data output from the analogue-to-digital converter on a time-serial basis, and a processing unit for processing the data stored in the memory to thereby arithmetically determine the distance to the object on the basis of a peak appearing in an echo wavefrom reconstituted from the data, a time lapse from the emission of the light pulse to the appearance of the peak, and the frequency of the clock signal.
    Type: Grant
    Filed: October 3, 1991
    Date of Patent: January 12, 1993
    Assignee: Mitsubishi Denki K.K.
    Inventor: Masahira Akasu
  • Patent number: 5166881
    Abstract: A following control apparatus for an automotive vehicle is disclosed which controls the output of an engine and the brakes of a vehicle so as to maintain a target vehicle separation from a preceding vehicle. A control unit calculates a target drive force for the vehicle and controls the brakes and the throttle valve of the engine so as to achieve the target drive force. In one form of the invention, the target drive force when the vehicle is starting from a standstill is calculated based on the relative speed of the vehicle and the preceding vehicle and the difference between the measured vehicle separation and the target vehicle separation when the measured vehicle separation is at least the target vehicle separation, but is calculated based on the relative speed of the vehicle independently of the vehicle separation when the measured vehicle separation is less than the target vehicle separation.
    Type: Grant
    Filed: January 15, 1991
    Date of Patent: November 24, 1992
    Assignee: Mitsubishi Denki K.K.
    Inventor: Masahira Akasu
  • Patent number: 5115397
    Abstract: A fuel injection control apparatus for an internal combustion engine in which the air taken into the intake manifold by a Karman vortex detector. However, the amount of fuel injected is based on a calculated intake volume. The calculated intake volume for a time interval is a weighted sum of the measured volume and the calculated intake volume of the previous period. This overaging amounts for surge storage in the intake manifold and other input paths.
    Type: Grant
    Filed: July 3, 1990
    Date of Patent: May 19, 1992
    Assignees: Mitsubishi Jidosha Kogyo K.K., Mitsubishi Denki K.K.
    Inventors: Akira Takahashi, Yoshiaki Kanno, Jiro Sumitani, Katsuya Nakamoto, Takeo Sasaki, Masahira Akasu
  • Patent number: 5007397
    Abstract: An ignition timing control device according to the present invention compensates the energizing preparatory time taken until commencement of energizing an ignition coil in reference to the ignition time which alters as the revolution of an engine varies, e.g., during acceleration.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: April 16, 1991
    Assignee: Mitsubishi Denki K.K.
    Inventor: Masahira Akasu
  • Patent number: 4959996
    Abstract: A signal control generator for a multi-cylinder internal combustion engine has a position sensor which generates output pulses which indicate prescribed rotational angles of the crankshaft of the engine for each cylinder. The output pulse for a prescribed reference cylinder of the engine is shorter than the pulses for the other cylinders. The reference cylinder is recognized by comparing the pulse width or the duty cycle of each pulse with the pulse width or the duty cycle for previous pulses corresponding to other cylinders of the engine. The period between consecutive output pulses is used to control the ignition timing of the engine.
    Type: Grant
    Filed: September 26, 1989
    Date of Patent: October 2, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 4945875
    Abstract: The rate of variation in the rotational period of an engine is determined by the use of a pulse signal generated according to the rotation of an engine crankshaft, and the value of the rate of variation thus determined is compared with a previously set value of judgement of the rate of variation. When the rate of variation is under the judged value, ignition is performed at an advance or retard timing given by calculation; and when the rate of variation exceeds the judged value, an ignition signal is used as a reference crank position signal in place of an ignition command signal obtained by calculation.
    Type: Grant
    Filed: March 3, 1989
    Date of Patent: August 7, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 4903210
    Abstract: A method for reducing knocking in an internal combustion engine providing an improved response to changes of operating conditions of the engine and which is capable of producing precise knocking control under all combinations of operating conditions. The knocking level, load condition and rotational speed of the engine are detected. At addresses of a memory defined by the load and speed of the engine, values are stored which are calculated in accordance with the detected knocking levels, and ones of these values are read out in accordance with addresses corresponding to a present combination of a load condition and engine speed. At least one control parameter, such as the ignition timing, is corrected on the basis of the values read out from the memory and the detected knocking level. The values stored in the memory are changed at predetermined periods bidirectionally.
    Type: Grant
    Filed: October 18, 1985
    Date of Patent: February 20, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 4895127
    Abstract: An ignition timing control device for an internal combustion engine includes a load detector for detecting a load on the engine, an engine-revolution detector for detecting a number of revolution of the engine, a cylinder discrimination signal generator for generating cylinder discrimination signals, an operating device for operating the optimum ignition timing for the engine based on the outputs from the load detector and the engine-revolution detector, a drive signal generator for generating drive signals corresponding to the ignition timing for each of the ignition coils provided in each cylinder, and a distributor for distributing the drive signal to each of the ignition coils in an appropriate sequence on the basis of the cylinder discrimination signal. The distributor is provided with a distribution sequence maintaining device for maintaining the distribution sequence of the drive signal, even when the cylinder discrimination signal is stopped.
    Type: Grant
    Filed: May 11, 1988
    Date of Patent: January 23, 1990
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshiro Hara, Takanori Fujimoto, Masahira Akasu
  • Patent number: 4811714
    Abstract: An ignition timing control device for an internal combustion engine in which optimum ignition timing control is provided under all operating conditions. Control values for providing reference ignition timing characteristic are stored in a memory. These values are read out from the memory in response to the output of an engine operating condition sensor and are corrected using a correction value obtained in response to the output of a knock detector with the correction value having a positive, zero or negative value. Accordingly, the reference ignition timing characteristic is maintained near the optimum ignition timing of the knock limit of the engine to thus suppress the occurrence of engine knock at the start of a control operation.
    Type: Grant
    Filed: March 22, 1984
    Date of Patent: March 14, 1989
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 4633835
    Abstract: An apparatus for controlling the timing of ignition in an engine by delaying, upon detection of knocking in the engine, a reference ignition timing preset in accordance with each running mode of the engine. The apparatus is equipped with abnormality detecting means which functions in response to any fault or malfunction of knock detecting means and prevents alteration of the ignition timing in the direction of angular advance.
    Type: Grant
    Filed: February 26, 1986
    Date of Patent: January 6, 1987
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu
  • Patent number: 4586474
    Abstract: An apparatus for suppressing knock in an engine by first detecting the knock and sequentially renewing a control quantity, which is fed to means for controlling the running mode of the engine, in the direction of knock suppression until the knock detection output becomes nonexistent. The apparatus is equipped with means capable of prohibiting renewal of the control quantity when the engine is in any transient running state such as a stage immediately after its start, thereby preventing unstable running of the engine.
    Type: Grant
    Filed: June 1, 1984
    Date of Patent: May 6, 1986
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Masahira Akasu