PROXIMITY DETECTION METHOD AND SYSTEM
3 Assignments
0 Petitions
Accused Products
Abstract
The invention concerns a proximity detection of buried conductive structures before or while digging in areas being excavated. By means of the enclosed methods, devices, and setups, the ability and accuracy of the detection of underground structures, such as conduits, pipes, etc. is improved by conductively applying a current into the structure through the soil. The thereby emitted electromagnetic field is detected by a movable detection- unit over ground. According to this electromagnetic field the detection-unit can determine the proximity of the structure and issue a warning signal. This warning signal helps an operator of an earth moving machine to avoid a collision with the structure.
-
Citations
34 Claims
-
1-15. -15. (canceled)
-
16. A proximity detection method for a conductive, buried structure, comprising the steps of:
-
generating an alternating electrical current of a desired frequency by a current-source; introducing the electrical current into the structure so that an electromagnetic field is emitted, by the current-carrying structure; detecting the time-variable electromagnetic field by a mobile detection-unit above ground that is electrically insulated from the ground; determining the proximity of the structure to the detection-unit according to the detected electromagnetic field; indicating the proximity as a distance information between the structure and a reference point with a known position relative to the detection-unit, wherein at least first and second single point electrodes are stuck into soil so that the electrodes are surrounded by soil material, are spaced approximately 5-200 meters apart from each other, and are introducing the electrical current by conduction directly into the soil such that the flow-path of the electrical current is; from the current-source to the first electrode; from the first electrode through soil to the structure so that they are conducted by soil material only; following at least a part of the structure as path of least resistance underground; from the structure through soil to the second electrode so that they are conducted by soil material only; and from the at least second electrode to the current-source by an insulated cable above ground, wherein the first and the second electrode define a detection-area wherien the step of detecting the electromagnetic field is executed. - View Dependent Claims (17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33)
-
-
34. A proximity detection system for a conductive, elongate, buried structure underground conduit or wiring system at a construction site, comprising:
-
a current-source for generating an alternating electrical current of a desired frequency; a connection-set for introduction of the electrical current into the structure, in such a way that a time-variable electromagnetic field is emitted by the structure; a mobile detection-unit above ground electrically insulated from soil, built in such a way that the electromagnetic field is detected and the proximity of the structure to the detection-unit is determined according to the electromagnetic field and the proximity is indicated as a distance information between the structure and a reference point of which a position relative to the detection-unit is known, wherein the connection-set comprises; at least a first and a second ground-spike, each having an electrode to be stuck into soil so that the electrode is surrounded by soil material, and an insulated cable with a length of approximately 5-200 meters, connected to the current-source and the electrode, whereby the connection-set is built in a way for conductively introducing the electrical current into soil in such a way that the flow-path of the electrical current is; from the current-source to the first electrode; from the first electrode through soil to the conductive structure , so that they are conducted by soil material only; following the structure as path of least resistance inside the soil; from the structure through soil to the second electrode, so that they are conducted by soil material only; and from the second electrode back to the current-source by the cable above ground, wherein the first and the second electrode define a detection-area within which the structure is detectable by the detection-unit.
-
Specification