Position detecting device

• US 4,470,108 A
• Filed: 12/01/1981
• Issued: 09/04/1984
• Est. Priority Date: 12/01/1981
• Status: Expired due to Fees

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Kimura, Masatoshi, Kato, Yoshito, Hashimoto, Toshio
• Primary Examiner(s): Ruggiero, Joseph F.
• Application Number:
  US06/326,251
• Time in Patent Office: 1,008 Days
• Field of Search: 364/142, 364/167, 364/174, 364/175, 364/560, 364/561, 364/562, 364/474, 364/475, 377/2, 377/15, 377/16, 377/17, 318/603, 318/626, 318/467, 318/468
• US Class Current: 700/56
• CPC Class Codes: G05B 19/23 for point-to-point control
• CPC Class Codes: G05B 2219/34052 Software counter
• CPC Class Codes: G05B 2219/34215 Microprocessor
• CPC Class Codes: G05B 2219/36159 Detachable or portable programming unit, display, pc, pda
• CPC Class Codes: G05B 2219/37183 Marker or index or coded information as well as position pulses
• CPC Class Codes: G05B 2219/41092 References, calibration positions for correction of value position counter
• CPC Class Codes: G05B 2219/41358 Transmission, variable gear ratio
• CPC Class Codes: G05B 2219/50084 Keep position, setup parameters in memory

Abstract

Pulses indicating movement distance are frequency divided to a desired resolution and then counted in a microprocessor in accordance with the direction of movement. The position count value addresses a data memory storing switch output data corresponding to desired detection positions.

Claims

1. A position detecting device for detecting the position of a movable object within a movement range comprising:

means for generating a train of distance pulses in accordance with movement of said object;

means for counting said pulses to generate a position signal representing the position of said object; and

means, responsive to said position signal, for generating at least one switch output at a plurality of different count values of said position signal;

wherein said means for generating comprises;

a data memory for storing switch output data representing said at least one switch output at a plurality of address locations;

means for addressing said memory in accordance with said count values; and

means for providing said at least one switch output in accordance with the contents of addressed memory locations;

wherein said means for generating the train of distance pulses comprises;

a pulse generator for generating movement pulses in accordance with object movement; and

a programmable frequency divider for receiving said movement pulses and providing a lower frequency distance pulse train output to be supplied to said means for counting; and

wherein said programmable frequency divider comprises;

a count memory addressed both by the output of said second counting means and also by a signal representing a desired frequency division ratio; and

a monostable multivibrator receiving an output of said count memory as an input and being clocked by said movement pulses, the output of said monostable multivibrator comprising said distance pulses.

2. A position detecting device as claimed in claim 1, wherein said means for counting and means for addressing comprise a microprocessor.

3. A position detecting device as claimed in claim 1, wherein said data memory is programmable, further comprising means for selectively changing said switch output data and the address of said switch output data in said data memory.

4. A position detecting device as claimed in claim 1, wherein said data memory is addressed further in accordance with the direction of movement of said object and said means for providing provides different switch outputs for a portion of the position signal of said object depending upon the direction of travel.

5. A position detecting device as claimed in claim 1, wherein each of said switch comprises a plurality of bits.

6. A position detecting device as claimed in claim 1, wherein said means for counting counts said distance pulses in a direction corresponding to the direction of movement of said object.

7. A position detecting device as claimed in claim 1, further comprising direction detecting means for receiving said movement pulses and providing an output indicating the direction of movement of said object.

8. A position detecting device for detecting the position of a movable object, comprising:

direction discriminating means for receiving a pulse train signal including forward movement direction pulses and reverse movement direction pulses to produce a direction discriminating signal and a first pulse signal indicative of the distance moved;

programmable frequency divider means for receiving the first pulse signal and a frequency-division ratio-selecting signal to produce a frequency-divided pulse signal which is obtained by subjecting the first pulse signal to frequency division in accordance with the frequency-division ratio-selecting signal, said divider means comprising means for counting the first pulse signal, memory means for receiving the output signal of said counting means as an address signal and the frequency division ratio selecting signal, and for providing an output signal representative of data stored in an address of said memory means, which address is assigned by the address signal, and monostable multivibrator means for receiving the output signal from said memory means and the first pulse signal to produce the frequency-divided pulse signal; and

controlling means comprising data memory means for storing position number data, distance data and switch output data, said controlling means receiving the frequency-divided pulse signal and the direction discriminating signal and providing the switch output data obtained by subjecting the received signals and the data stored in said data memory means to a calculation in accordance with a predetermined control program.