Patent Number: 053393392
Section: description

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS This industrial site 5 has not shown automatic installations, whose operation is checked by sensors 10 distributed over the site 5 and which are grouped around the collection or reading points 12. Equipments 11 having a certain operating state are also linked with these collection points and can be in the form of valves, switches, etc. Each collection point 12 is pinpointed on the site 5 and indicated by a label carrying an identification bar code of the said point. In order to locate a collection point 12, the site 5 can e.g. be divided into levels, level 1 corresponding to a building 14, level 2 to part of the building designated as a cell 16, level 3 to part of the cell designated as a unit 18, whereby the latter can have several collection points 12. In the drawing, the building 14 is subdivided into two cells 16 separated by a mixed line. The cells 16 are subdivided into units 18 by broken lines. The site 5 also has at least one control room 20 in which is installed at least one central computer 22 connected to a radiofrequency transceiver 24. The computer 22 can be of the microcomputer type. Various data are contained in a general file kept up to date after each round. This file recorded in the central computer 22 contains all the collection points 12 to which are allocated the identification references permitting their location. The file also contains the list of sensors 10 and equipments 11 grouped around the collection points 12. These sensors 10 and equipments 11 are indicated by identification references. This list in the file is completed by various informations, e.g. the type of sensor (thermal, electric, sensitive to radiation, sensitive to fumes) or equipment (valve, switch, elevator), the geographical location, the normally expected characteristics or values, tolerance thresholds, the checks to be carried out on the data collected during the rounds, the values obtained during the different rounds already performed, the time and date of these readings, the measuring units used and any other information making it possible to carry out an effective inspection, such as e.g. assistance comments on the decision regarding each of the sensors and equipments. Inter alia, this file makes it possible to display on a video monitor of a plan of the industrial site equipped with all the collection points, the sensors and equipments to be monitored. Before starting on his round, the watchman chooses from within the central file a sequence of collection points 12, sensors 10 to be checked and equipments to be checked and/or whose operating state is to be modified. This sequence is recorded in the central computer 22 and is defined by the performance course of the round on the site 5. Recording also takes place of the informations (or part thereof, but at least the reference values, historical values corresponding e.g. to the last five readings, tolerance thresholds and assistance comments on the decision) concerning the collection points 12, the sensors 10 and the equipments 11 to be monitored. Standard paths provided with information relating thereto are also available. They make it unnecessary for the watchman to redefine his complete path when starting out on each occasion. These standard paths can be modified at random. When the sequence or combination has been established, a theoretical time necessary for the path between each collection point 12 is defined. This time is recorded in a memory of the central computer 22 for each path between two collection points 12. Each round starts from the control room 20, where the watchman copies again the sequence established, as well as the informations relating thereto in a memory of a portable microcomputer 26 equipped with a screen associated with a radiofrequency transceiver 28. This microcomputer 26 is also equipped with a wand reader for reading a bar code 30. On the basis of said data, the microcomputer 26 carried during the round guides the watchman by indicating to him towards which collection point 12 he should move, together with the equipments or sensors 10 to be checked. At each passage to a collection point 12, the watchman reads the bar code carrying the identification reference of the point using the wand reader 30. This bar code reading constitutes a validation of the passage of the watchman to the collection point 12. The microcomputer 26 records the reading and allocates thereto a passage time table by means of an internal clock. Moreover, the microcomputer 26 displays on the screen a message confirming to the watchman that the collection point is indeed that provided in the sequence constituting the round. In the opposite case, the display on the screen of the portable microcomputer indicates the collection point normally provided. At this stage the operator has the choice between confirming the modification of the instruction provided by validating said information on the keyboard or of moving to the displayed collection point and carrying out again in situ an identification reading by reading the bar code. At each reading of an identification reference of the collection point, a pinpointing or location signal is transmitted by the transmitter 28 connected to the portable microcomputer 26 to the receiver 24 connected to the central computer 22. The effect of the reception of the signal is to trigger an internal clock within the computer 22. If the following validation has not taken place when the theoretical time between two validations and which has been defined beforehand has elapsed, an alarm is given by the central computer 22. Initially said alarm can be a signal transmitted by the transmitter 24 associated with the central computer 22 to the receiver 28 associated with the portable microcomputer 26. This signal triggers a sound and/or visual transmission or the display of a message on the screen of the microcomputer 26. The watchman must then reply by a message which he enters into the microcomputer 26 and which is transmitted by radiofrequency transmission to the computer 22. If no response is received, the computer 22 can alert an emergency team, which will intervene as quickly as possible when the location of the watchman becomes known. At each collection point 12, the watchman collects the informations supplied by the sensors 10 and records them in a memory of the portable microcomputer 26. He also carries out the checks and/or operating state changes of the equipments 11 and records information relating to said equipments. For each sensor 10 or equipment 11, the microcomputer 26 makes a comparison between said informations and the prerecorded values corresponding to a normal operation of the installations. This comparison and also the definition of tolerance thresholds makes it possible to detect any operational abnormality. Following each acquisition of informations concerning the sensors 10 or equipments 11, the watchman must carry out a validation. When the validated value is non-standard, via the transmitter 28, the microcomputer 26 transmits a message to the central computer 22. As a function of the defective sensor 10 and the type of abnormal condition, said central computer alerts a maintenance team, which can operate rapidly and effectively. Optionally, the central computer 22 can automatically interrupt certain electrical or other circuits. When an abnormal operating state is detected, the watchman can display historical informations stored in the portable microcomputer 26 and which concern measurements performed during preceding rounds. The portable microcomputer 26 also displays assistance comments on the decision and, as a function of the particular case, the watchman can change the passage sequence to the collection points 12, check sensors 10 or equipments 11 not planned during the definition of the round, or even interrupt his round, whilst still keeping the central computer 22 informed via the radiofrequency link. For each checked sensor 10 or equipment 11, the watchman is responsible for recording comments on the operation of the installations. These comments favour an effective preventative maintenance, because they make it possible to avert incidents. For example, a maintenance team alerted by these comments can replace a particular part before it deteriorates and in fact as soon as it has deficiency symptoms. At the end of he round, the informations read on the sensors 10 and contained in a memory of the portable microcomputer 26 are recorded in a memory of the central computer 22 in such a way that they can be processed there, whilst the central file is also updated. The processing can consist of statistics concerning a large number of rounds, evolutions of informations supplied by the sensors, or an analysis of variations in the reaadings of the sensors. If desired, a written paper report of all the informations can be obtained. The process according to the invention makes it possible to follow several watchmen from the same control room. The permanent link between the central computer and the portable microcomputer enables decisions to be taken rapidly and effectively. As a result of this link and the informations contained in the portable microcomputer, the watchman can analyze abnormal situations and act as a consequence thereof. He is responsible for his actions, whilst still being controlled by the central computer.