Control system for automated manipulator device

• US 4,439,672 A
• Filed: 07/29/1982
• Issued: 03/27/1984
• Est. Priority Date: 08/07/1981
• Status: Expired due to Fees

• Current Assignee: Lord Electric Company Incorporated
• Original Assignee: Lord Electric Company Incorporated
• Inventors: Salaman, Roy G.
• Primary Examiner(s): Rubinson, G. Z.
• Assistant Examiner(s): Lev, Robert
• Application Number:
  US06/402,994
• Time in Patent Office: 607 Days
• Field of Search: 235/487, 235/462, 235/463, 235/466, 235/494, 235/473, 235/472, 235/456, 235/454, 235/455, 235/458, 235/474, 235/492, 235/380, 235/382, 235/493, 235/488, 250/237 R, 250/231 R, 250/231 SE
• US Class Current: 235/462.01
• CPC Class Codes: G21F 9/305 Glass or glass like matrix C03B5/005 takes precedence; compositional aspects C03C

Abstract

A control system controls the movement and position of an automated device as it moves along a movement track. The control system comprises a chart extending stationarily transversely adjacent along an operative portion of the movement track which includes a light reflective code uniquely defining each increment of length of the chart. A light source is carried by the movement device for illuminating the chart and creating the reflected optical signals. A camera device is also carried by the movement device and receives the optical signals. Corresponding electrical signals are derived and are utilized by a computer processor to control the position and movement of the movement device. The chart includes a plurality of parallel bars extending along the length of the chart. A portion of the bars define, in binary code, the unique optical signal reflected from each distance increment along the chart. A remaining portion of the bars assure the integrity of the reflected optical signal.

Claims

1. In an automated device operative to move along at least one movement track and having motor means for moving the automated device along the movement track, an improved control system for controlling the movement and position of the automated device along the movement track comprising:

means defining a chart having a width and a length and stationarily positioned transversely adjacent the movement track along a predetermined operative portion of the movement track over which the automated device is to be movably controlled, the length of the chart extending along the movement track and the width of the chart extending transversely with respect to the movement track, said chart having a radiation reflective code extending across a portion of the width of the chart and along the operative length of the chart which defines the length of the chart and hence the operative portion of the movement track into a plurality of distance increments, the code further defines each distance increment by a unique predetermined pattern of radiation reflected from the code at each distance increment;

radiation source means for emanating radiation onto the chart at a position adjacent the automated device as the automated device moves along the movement track, the radiation reflected from the code at each distance increment defining the predetermined pattern of reflected radiation unique to that distance increment;

camera means attached to and carried by the automated device during movement along the movement track relative to the chart, said camera means receptive of radiation from said source means reflected in a scanning path extending fully across and beyond the transverse width of the chart to assure reception of the predetermined pattern of radiation reflected from the code at each distance increment under conditions of shifts in transverse position of the chart relative to the movement track;

a part of said code including means reflectively indicative of the beginning and the ending of the transverse width of the code at each distance increment;

said camera means further including means for converting each predetermined pattern of reflected radiation into an increment signal uniquely indicative of the particular distance increment from which the predetermined pattern of reflected radiation was reflected; and

processor means including a memory and an input control means for entering into said memory at least one information signal, each information signal corresponds to an increment signal corresponding to a distance increment along the operative portion of the track, said processor means being connected to said camera means to receive each increment signal from said camera means, said processor means further operatively controlling said motor to move said automated device along the movement track in predetermined relation to the information signal and each increment signal supplied by said camera means.

2. An invention as defined in claim 1 wherein:

said chart is an elongated strip chart which includes a plurality of parallel bars extending along the length of the chart, a lesser plurality of said bars defines a group of data bars, two other of said bars define a stop bar and a start bar, respectively, and one other of said bars defines a sample bar;

each of said data bars include equal length sequential segments of alternately different radiation reflectivity characteristics, the reflectivity characteristics of the plurality of data bars defines the predetermined pattern of reflected radiation for each distance increment in binary code when viewed across the width of said strip chart perpendicular with respect to the length of said bars, transitions from one segment to another sequential segment along each data bar occur at transitions between distance increments along said strip chart;

said group of data bars are preceded and followed by the start bar and the stop bar respectively across the width of the strip chart, the start bar has a consistent radiation reflectivity characteristic along its entire length, and the stop bar has a different consistent radiation reflectivity characteristic along its entire length;

the sample bar includes a plurality of equal length sample segments of one radiation reflectivity characteristic and a plurality of equal length transition segments of a different radiation reflectivity characteristic, the sample segments alternate in position with the transition segments along the length of the sample bar, and each transition segment is positioned transversely perpendicular with respect to the length of the data bars at the transitions between segments of the data bars; and

the predetermined pattern of reflected radiation received by said camera means from the scanning path extends across the width of said strip chart transversely perpendicular with respect to the length of said bars, and the scanning path has a dimension extending along the length of said strip chart which is less than the length of each sample segment of said sample bar.

3. An invention as defined in claim 2 wherein:

said camera means is responsive to radiation reflected from each of said plurality of bars of said strip chart and supplies separate bar signals corresponding to each bar of said strip chart and indicative of the radiation reflectivity characteristics of each of said bars and segments thereof; and

said camera means further supplies a start bar signal and a stop bar signal indicative of the beginning and the end, respectively, of the group of data bar signals.

4. An invention as defined in claim 3 wherein:

the plurality of bars of said strip chart further include a trigger bar in addition to those bars aforementioned, and the trigger bar extends along one transverse outer side of the plurality of bars, and the stop bar extends along the opposite transverse outer side of the plurality of bars; and

said means of said code for indicating the beginning and the ending of the full transverse width of the code on the strip chart comprise the trigger and stop bars, respectively.

5. An invention as defined in claim 4 wherein the radiation emanated from said radiation source means is light, and the radiation which the code of said chart reflects is light, and said camera comprises a linear array of photodiodes operatively receiving to light reflected in the scanning path from the code of said chart and converting the reflected light into the increment signal, and the increment signal is electrical.

6. An invention as defined in claim 5 wherein said plurality of bars of said code are located on said strip chart from one transverse side to the other transverse side in the following sequential order:

(a) the trigger bar,

(b) the sample bar,

(c) the start bar,

(d) the group of data bars, and

(e) the stop bar.

7. An invention as defined in claim 6 wherein said plurality of bars of said code further comprise in continuing sequential order:

(f) a second start bar which has the same light reflectivity characteristic along its entire length as the first start bar aforementioned;

(g) a second group of a plurality of data bars in addition to the group of data bars first aforementioned, the second group of data bars is similar to the first group except that the length of the shortest segment of any data bar of the second group is greater than the length of the longest segment of any data bar of the first group; and

(h) a second stop bar which has essentially the same light reflectivity characteristic along its entire length as the stop bar first aforementioned.

8. An invention as defined in claims 6 or 7 wherein said camera means is included as part of a transducer means of said control system, and said transducer means comprises:

first means for supplying the separate bar signals corresponding to each bar of said strip chart and indicative of the light reflectivity characteristic of each bar and segments thereof, said first means supplying said bar signals in the same recited sequence that said bars are transversely positioned on said chart;

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 indicative 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 electrical increment signal.

9. An invention as defined in claim 8 wherein said fourth means is further responsive to the start bar signal and stop bar signal from said first means.

10. An invention as defined in claim 9 wherein said third means includes comparing means for comparing the sample bar signal with a predetermined signal reference and preventing the supplying of the valid scan signal if the sample bar signal is less than the predetermined reference for a predetermined time prior to termination of the synch window signal.

11. An invention as defined in claim 10 wherein said first means further comprises:

means responsive to the light reflected from each bar of said chart in the scanning path for supplying a plurality of electrical pulses representative of the light reflectivity characteristics of each bar and segment thereof, each of said plurality of electrical pulses having a signal level representative of the light reflectivity characteristics of a partial portion of the width of each bar in the scanning path; and

demodulator means responsive to the signal level of said electrical pulses, said demodulator means supplying the separate bar signals from said first means, said demodulator means supplying the separate bar signals at one signal level so long as the level of electrical pulses exceeds a predetermined threshold level and supplying the separate bar signals at a different signal level upon the level of said electrical pulses being less than the predetermined threshold level.

12. An invention as defined in claims 6 or 7 wherein for each bar signal said camera means supplies a plurality of electrical pulses, each electrical pulse having a signal level representative of the light reflectivity characteristic of a partial portion of the width of each bar in the scanning path;

and further comprising;

demodulator means responsive to the occurrence and signal level of said electrical pulses for supplying the bar signal at one signal level so long as the signal level of said electrical pulses exceeds a first predetermined threshold level and for supplying the bar signal at a different level upon the signal level of said electrical pulses being less than the first predetermined threshold level, said demodulator means supplying 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 a number of electrical pulses representative of the light reflectivity characteristic of an initial transverse half width portion of said sample bar;

comparing means receptive of electrical pulses from said camera means, for comparing the signal level of each of the electrical pulses from said camera means 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 the supply of electrical pulses which have signal levels from said camera means less than the second predetermined level;

gating means receptive of the synch window signal 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 the bar signals from said demodulator means for converting said bar signals from said demodulator means into a binary, multi-digit electrical increment signal.

13. An invention as defined in claim 12 wherein:

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

14. An invention as defined in claim 13:

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 occurring approximately at the time center of the bar signals supplied from said demodulator means; and

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

15. An invention as defined in claim 1 wherein each distance increment is of equal length along the one movement track.

16. An invention as defined in claim 1 wherein said radiation source means is carried by said automated device.