System for controlling position and movement of manipulator device from absolute distance data standard

• US 4,385,028 A
• Filed: 03/20/1980
• Issued: 05/24/1983
• Est. Priority Date: 03/20/1980
• Status: Expired due to Term

• Current Assignee: Lord Electric Company Incorporated
• Original Assignee: Lord Electric Company Incorporated
• Inventors: Salaman, Roy G.
• Primary Examiner(s): Walsh, Donald P.
• Application Number:
  US06/132,272
• Time in Patent Office: 1,160 Days
• Field of Search: 376/258, 376/259, 376/248, 376/264, 376/268, 340/147 MT, 340/146.3 R, 340/146.3 AG, 340/685, 340/686, 340/707, 340/708, 340/810, 178/18, 178/15, 250/231 SE, 250/237 R
• US Class Current: 376/264
• CPC Class Codes: B66C 13/46 Position indicators for suspended loads or for crane elements
• CPC Class Codes: B66C 13/48 Automatic control of crane drives for producing a single or repeated working cycle; Programme control
• CPC Class Codes: G05B 19/39 using a combination of the means covered by at least two of the preceding groups G05B19/21, G05B19/27 and G05B19/33
• CPC Class Codes: G21C 19/02 Details of handling arrangements
• CPC Class Codes: Y02E 30/30 Nuclear fission reactors

Abstract

This system incorporates a uniquely coded longitudinally extending absolute distance standard or code chart. The code chart includes bars and segments of different light reflectivity characteristics which uniquely define every different distance increment along the chart. Preferably the chart is binary coded. A transducer optically detects the code at each different distance measurement increment and converts the code into electrical signals. The electrical signals operatively control a manipulator device which moves along a movement track parallel to the stationarily positioned chart. The transducer includes means for detecting the code at or near the center of each distance measurement increment, rather than at the edges of the distance measurement increments where the code on the chart undergoes transitions. A sample bar extending along the chart defines the distance measurement increments and the points at which the code at or near the center of the distance measurement increments is to be sampled. This system is particularly applicable for controlling the movement and position of a manipulator crane used in nuclear power plants to manipulate nuclear core elements.

Claims

1. In a manipulator device including means for grappling nuclear core elements of a nuclear reactor, a system for generating a binary, multi-digit electrical output signal representative of each separate increment of position along an extended measurement dimension, comprising:

a chart positioned stationarily parallel to the measurement dimension and divided into a plurality of equal length distance measurement increments along the length of said chart, said chart further including light reflective means formed thereon defining a unique and different code identifying and representative of each different distance measurement increment, said light reflective means comprising a plurality of parallel bars extending longitudinally along the chart, said plurality of parallel bars comprising the following bars;

a trigger bar having essentially uniform light reflectivity characteristics along its entire length;

a sample bar having a plurality of equal length sample segments of one light reflectivity characteristic and a plurality of equal length transition segments of a substantially different light reflectivity characteristic alternating with the sample segments along the entire length of the sample bar; and

a group of a plurality of data bars, each data bar of said group including segments of alternately substantially different light reflectivity characteristics along the length of each said data bar, the length and light reflectivity characteristics of the segments of the data bars of the group defining the code representative of each distance measurement increment when viewed transversely perpendicular of said bars through a point on each sample segment;

camera means responsive to optical signals reflected from each of the bars of said chart along a linear path extending transversely perpendicular with respect to the bars across the chart, said camera means supplies a plurality of electrical pulses corresponding to each said bar, each of the electrical pulses of the plurality corresponding to a bar has a signal level representative of the light reflectivity characteristics of a portion of that bar along the linear path extending transversely perpendicularly across the chart;

demodulator means responsive to said electrical pulses and the signal level of said electrical pulses from said camera means, said demodulator means supplying a bar signal at one level so long as the level of said electrical pulses exceeds a first predetermined threshold level and supplying the bar signal at a different level so long as the level of said electrical pulses remains less than the first predetermined threshold level, said demodulator means supplying at least one bar signal corresponding to each bar of said chart;

counter means responsive to the trigger bar signal from said demodulator means for delivering a synch window signal of time duration which terminates approximately after said camera means supplies electrical pulses representative of the light reflectivity characteristics of an initial transverse half portion of said sample bar;

comparing means receptive of electrical pulses from said camera means for comparing the signal level of each of said received electrical pulses with a second predetermined threshold level and for supplying those electrical pulses which have levels from said camera means exceeding the second predetermined threshold level and for terminating those electrical pulses which have levels from said camera means less than the second predetermined level;

gating means receptive of the synch window signal from counter means and of the electrical pulses supplied from said comparing means, said gating means supplying a valid scan signal upon receipt of a predetermined plurality of electrical pulses during the time duration of said synch window signal; and

interface means responsive to said valid scan signal and said bar signals from said demodulator means for converting said bar signals from said demodulator means into the binary, multi-digit electrical output signal.

2. A system as defined in claim 1 wherein:

said demodulator means supplies bar signals in the same sequence that said bars are transversely positioned on said chart.

3. A system as defined in claim 2:

further comprising second counter means in addition to the counter means first aforementioned, said second counter means being receptive of said synch window signal for supplying a plurality of center bar signals timed to occur approximately at the center of the bar signals from said demodulator means; and

wherein said interface means is further responsive to the center bar signal from said second counter means, said interface means converting each bar signal in sequence into parallel form upon receipt of the corresponding center bar signal.

4. A system as defined in claim 1 wherein said manipulator device comprises a nuclear manipulator crane comprising:

a first movement track extending in a first dimension;

a bridge assembly moveable along said first movement track;

a second movement track extending in a second dimension perpendicular to the first dimension, said second movement track being connected to said bridge assembly;

a trolley assembly moveable along said second movement track;

a mast attached to said trolley assembly; and

grappling means associated with said mast for contacting nuclear core elements of a nuclear reactor;

and wherein;

a first said chart extends along and is rigidly attached relative to said first movement track;

a first said transducer means is operatively attached to said bridge assembly to optically perceive light reflected from each bar of said first chart;

a second said chart extends along and is rigidly attached to said bridge assembly relative to said second movement track; and

a second said transducer means is operatively attached to said trolley assembly to optically perceive light reflected from each bar of said second chart.

5. A system for automatically controlling movement and position of means for manipulating and grappling nuclear core elements of a nuclear reactor, comprising in combination:

a first movement track extending in a first dimension;

a bridge assembly movable along said first movement track;

first motor means connected to said bridge assembly and operable to move said bridge assembly along said first movement track;

first motor control means for operatively controlling said motor means in response to motor control signals;

a second movement track extending in a second dimension perpendicular to the first dimension, said second movement track being connected to said bridge assembly;

a trolley assembly movable along said second movement track;

second motor means connected to said trolley assembly and operable to move said trolley assembly along said second movement track;

second motor control means for operatively controlling said motor means in response to motor control signals;

a mast attached to said trolley assembly;

grappling means associated with said mast for contacting and grappling the nuclear core elements of the nuclear reactor;

a first chart positioned stationarily parallel to said first movement track;

a second chart positioned stationarily parallel to said second movement track;

each of said charts are divided into a plurality of equal length distance measurement increments along the length of each chart, each chart further including light reflective means formed thereon defining a unique and different code identifying and representative of each different distance measurement increment, said light reflecting means comprising a plurality of parallel bars extending longitudinally along each chart, said plurality of parallel bars comprising the following bars;

a trigger bar having essentially uniform light reflectivity characteristics along its entire length;

a sample bar having a plurality of equal length sample segments of one light reflectivity characteristic and a plurality of equal length transition segments of a substantially different light reflectivity characteristic alternating with the sample segments along the entire length of the sample bar; and

a group of a plurality of data bars, each data bar of said group including segments of alternately substantially different light reflectivity characteristics along the length of each said sample bar, the length and light reflectivity characteristics of the segments of the data bars of the group defining the code representative of each distance measurement increment when viewed transversely perpendicular to said bars through a point on each sample segment;

a first transducer means operatively associated with said bridge assembly for optically perceiving light reflected from said first chart;

a second transducer means operatively associated with said trolley assembly for perceiving light reflected from said second chart;

each said transducer assembly comprising first, second, third and fourth means defined as follows;

first means for supplying a separate bar signal corresponding to and representative of the light reflectivity characteristic of each bar of the chart along a linear path extending transversely perpendicular with respect to said bars, said first means supplying said bar signals in serial order in the same order that said trigger bar, said sample bar, and said group of data bars are recited herein;

second means responsive to the trigger bar signal from said first means for delivering a synch window signal of time duration which terminates after said first means supplies the sample bar signal;

third means for gating the synch window signal with the sample bar signal and for supplying a valid scan signal if the sample bar signal is representative of light reflected from a sample segment of the sample bar prior to termination of the synch window signal; and

fourth means responsive to said valid scan signal for converting the sequence of data bar signals into a binary multi-digit output signal at each distance measurement increment; and

computer processor means receptive of the multi-digit output signal for supplying motor control signals to said first and second motor control means, said motor control signals being determined at least in part by said multi-digit output signals.

6. A system as defined in claim 5 wherein each said chart further includes the following bars:

a start bar having essentially the same light reflectivity characteristic along its entire length, said start bar being positioned transversely intermediate the sample bar and the group of a plurality of data bars; and

a stop bar having essentially the same light reflectivity characteristic along its entire length, the light reflectivity characteristic of the stop bar being other than light reflectivity characteristic of the start bar, the stop bar being positioned next transversely adjacent from the group of a plurality of data bars.

7. A system as defined in claims 5 or 6 wherein the first, second, third and fourth means of said transducer means comprise:

camera means responsive to optical signals reflected from each of the bars of said chart along the linear path extending transversely perpendicular with respect to the bars, said camera means supplying a plurality of electrical pulses corresponding to each said bar, each of the electrical pulses of the plurality corresponding to a bar has a signal level representative of the light reflectivity characteristics of a portion of that bar along the linear path extending transversely perpendicular across the chart;

demodulator means responsive to said electrical pulses and the signal level of said electrical pulses from said camera means, said demodulator means supplying the bar signal at one signal level so long as the level of said electrical pulses exceeds a first predetermined threshold level and supplying the bar signal at a different level so long as the level of said electrical pules remains less than the first predetermined threshold level;

counter means responsive to the trigger bar signal from said demodulator means for delivering the synch window signal and for terminating the synch window signal approximately after said camera means supplies electrical pulses representative of the light reflectivity characteristics of an initial transverse half portion of said sample bar;

comparing means receptive of the electrical pulses from said camera means for comparing the signal level of each of said received electrical pulses with a second predetermined and different threshold level and for supplying electrical pulses so long as the signal level of said pulses exceeds the second predetermined level and terminating those electrical pulses which have levels from said camera means less than the second predetermined level;

gating means receptive of the synch window signal from said counter means and of the electrical pulses supplied from said comparing means, said gating means supplying a valid scan signal upon receipt of a predetermined plurality of electrical pulses during the time duration of said synch window signal; and

interface means responsive to said valid scan signal from said gating means and said bar signals from said demodulator means for converting the sequence of bar signals from said demodulator means into the binary multi-digit output signal.

8. A system as defined in claim 7:

a further comprising second counter means in addition to the counter means first aforementioned, said second counter means being receptive of said synch window signal for supplying a plurality of center bar signals timed to occur approximately at the center of the bar signals from said demodulator means; and

wherein said interface means further requires receipt of the center bar signal from said second counter means before converting each bar signal into the multi-digit output signal.