Patents Assigned to Hitachi Control Systems Inc.
  • Patent number: 5299287
    Abstract: A problem solving system including apparatus for representing a relationship between a goal including subgoals and its lower level subgoals and for achieving the goal as a strategy of a first kind. Apparatus is provided for repetitively dividing a goal including subgoals into its lower level subgoals according to the relationship between the goal and the subgoals. A strategy of a second kind is used to specify the functions to be performed by the apparatus to achieve the lowest subgoal. Apparatus is also provided for simplifying and solving a complicated problem by executing the goal including subgoals by use of the strategies of the first and second kinds.
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: March 29, 1994
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc., Hitachi Microcomputer Engineering Ltd.
    Inventors: Setsuo Tsuruta, Kiyomi Kishi, Kuniaki Matsumoto, Shigenobu Yanai, Kiminori Nakamura
  • Patent number: 5208898
    Abstract: A knowledge processing system in which a grade representing a degree at which an event is satisfied or unsatisfied is obtained depending on a condition part represented in a form of a logical arithmetic expression including an expression of a fuzzy logic and on a grade of satisfaction of the condition part generates rules on assumption of unmeasurable events associated with states of the external field of the system so as to add the rules to the rules related to the unmeasurable events. Forecast of a value of a measurable event is more correctly achieved depending on grades of satisfaction of the unmeasurable events and grades of satisfaction of measurable events. A warning may also be issued according to the forecasted value.
    Type: Grant
    Filed: May 30, 1989
    Date of Patent: May 4, 1993
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc.
    Inventors: Motohisa Funabashi, Tohru Otokita
  • Patent number: 5103479
    Abstract: There are provided an encipher method of enciphering message data made by a microcomputer or the like at a high speed by using encipher keys which have previously been stored in a smart card or the like and a decipher method of deciphering the ciphertext made by the encipher method at a high speed by using the encipher keys. The encipher method and the decipher method are suitable for, particularly, a 32-bit microcomputer and include a process expressed by the function Rot.sub.2 i(x) (i=2, 3, 4) in each process. Rot.sub.2 i(x) is the process to circular shift a data train x of 32 bits to the left or right by 2.sup.i bits (i=2, 3, 4).
    Type: Grant
    Filed: November 27, 1990
    Date of Patent: April 7, 1992
    Assignees: Hitachi Ltd., Hitachi Control Systems, Inc.
    Inventors: Kazuo Takaragi, Fusao Nakagawa, Ryoichi Sasaki
  • Patent number: 5003469
    Abstract: In a decentralized processing system comprising a multiplicity of processors linked together through a transmission medium, a method of processing data of variable length that can be relocated in the transmission medium wherein each processor stores in a blank area of its own memory the data received from the transmission medium using information that indicates the size of the data and location of the data stored in the processor.
    Type: Grant
    Filed: February 8, 1988
    Date of Patent: March 26, 1991
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc.
    Inventors: Akihiko Kamiyama, Katsumi Kawano, Kinji Mori
  • Patent number: 4982429
    Abstract: There are provided an encipher method of enciphering message data made by a microcomputer or the like at a high speed by using encipher keys which have previously been stored in a smart card or the like and a decipher method of deciphering the ciphertext made by the encipher method at a high speed by using the encipher keys. The encipher method and the decipher method are suitable for, particularly, a 32-bit microcomputer and include a process expressed by the function Rot.sub.2 i(x) (i=2, 3, 4) in each process. Rot.sub.2 i(x) is the process to circular shift a data train x of 32 bits to the left or right by 2.sup.i bits (i=2, 3, 4).
    Type: Grant
    Filed: April 27, 1989
    Date of Patent: January 1, 1991
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc.
    Inventors: Kazuo Takaragi, Fusao Nakagawa, Ryoichi Sasaki
  • Patent number: 4969190
    Abstract: A data encrypting system according to the CBC system involves a limitation in a range of a numerical value which expresses data (smaller than a predetermined integer N). The encrypting system has an encrypting apparatus including a block encrypting section for receiving data, which is expressed by an integer value X smaller than a predetermined integer value N, for executing a data conversionC=enc (X)where 0.ltoreq.C.ltoreq.N-1 using an RSA algorithm, and for outputting C; and an arithmetic operating section connected to receive data, as one input, which is expressed by an integer value M smaller than the integer value N, and the output C of the block encrypting section as the other input, for performing an arithmetic operation for both of the inputs so that a resultant arithmetic value is smaller than the integer value N, and for outputting the arithmetic value as an input of the block encrypting section.
    Type: Grant
    Filed: April 12, 1989
    Date of Patent: November 6, 1990
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc.
    Inventors: Kazuo Takaragi, Fusao Nakagawa, Yasuhiko Nagai, Ryoichi Sasaki
  • Patent number: 4683549
    Abstract: A sequence program for a system to be sequence-controlled is divided into a plurality of divisional programs, which are stored in a program memory of a sequence processor. A main program including a plurality of instruction blocks is read out from the system under control and the execution or non-execution status of the divisional program for the corresponding instruction block is determined and stored in the program memory of the sequence processor. An address table indicating correspondence between the divisional programs and their top addresses is stored in a data memory of a sequence control processor. The sequence processor cyclically executes the main program, and when it determines the need for execution of the divisional program in a certain instruction block, it issues an interrupt signal including identification information for identifying the corresponding divisional program to the control processor.
    Type: Grant
    Filed: May 7, 1984
    Date of Patent: July 28, 1987
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc.
    Inventor: Masaoki Takaki
  • Patent number: 4569012
    Abstract: Method and system for controlling fluid transportation in a pipe network are disclosed. Pressures and flow rates at a predetermined number of points in the pipe network which number is smaller than the number of demand nodes in the pipe network are detected, demand volumes at the demand nodes are estimated based on known flow and pressure balance requirements for the pipe network and the detected flow rates and pressures, and the flow transportation in the pipe network is controlled in accordance with the estimated demand volumes such that the pressures at the demand nodes are brought to a reference pressure so that the pressures at the demand nodes at points other than the predetermined points are also brought to the reference pressure.
    Type: Grant
    Filed: September 28, 1984
    Date of Patent: February 4, 1986
    Assignees: Hitachi, Ltd., Hitachi Control Systems, Inc.
    Inventors: Teruzi Sekozawa, Motohisa Funabashi, Shinichiro Miyaoka, Shigeyuki Shimauchi, Fumito Shinomiya, Teruo Takagi
  • Patent number: 4562552
    Abstract: A control method and apparatus incorporate a network model simulating hydraulic phenomena within a water distribution network whereby the pressures and flow rates within the water distribution network are controlled by an optimizing unit for inputting the current total demand as a model input and computing manipulated variables or control amounts for optimizing the pressures and flow rates in accordance with a network algorithm and a correction computing unit for computing the necessary control amount correction values for correcting the deviations from the estimated pressures and flow rates in accordance with a sensitivity matrix indicating the effects of variations in the control amounts on the pressures and flow rates.
    Type: Grant
    Filed: February 1, 1983
    Date of Patent: December 31, 1985
    Assignees: Hitachi, Ltd., Hitachi Control Systems Inc.
    Inventors: Shinichiro Miyaoka, Teruji Sekozawa, Motohisa Funabashi, Shinobu Hayashi