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title: System and method using a multi-plane curtain
abstract: A multi-plane scanner support system includes a bracket and a mirror block. The bracket is configured to be secured in a fixed orientation with respect to a scanner. And the mirror block is arranged to receive a scanning signal from the scanner and to reflect the scanning signal into a plurality of directions to create multiple scanning planes. The scanner can be a laser scanner. The scanner and multi-plane scanner support system can be attached to a material transport vehicle, for example, to provide safety functions. The vehicle can be manned or unmanned.
url: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&p=1&u=%2Fnetahtml%2FPTO%2Fsearch-adv.htm&r=1&f=G&l=50&d=PALL&S1=08169596&OS=08169596&RS=08169596
owner: Seegrid Corporation
number: 08169596
owner_city: Pittsburgh
owner_country: US
publication_date: 20090817
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The present inventive concepts relate to the field of safety scanning systems and vehicles using the same.

Material transport vehicles and systems such as fork lift trucks tuggers and the like are used in a wide variety of applications. Such vehicles can include manned vehicles and automated guided vehicles AGVs . Some such vehicles and systems can include sensors and scanners used for navigation and safety.

A mast can be part of or connected to vehicle . A light is mounted on the mast to communicate signals to nearby individuals such as signals used for warning and safety purposes. The laser scanner is also mounted on mast .

Bottom laser scanner is mounted on a front portion of the vehicle at a set height from a ground surface upon which the vehicle travels. The bottom laser scanner projects a laser beam in front of the vehicle to define two zones a safety zone and a warning zone . If the bottom laser scanner detects a body or object collectively body in the safety zone the scanner can send a signal to a controller not shown of the vehicle which in turn communicates to the drive mechanisms also not shown of the vehicle . In response to receipt of a signal indicating detection of a body in the safety zone the controller can cause the drive mechanisms to halt movement and or operation of the vehicle. The controller can also cause light to signal the presence of the condition. In this way bottom laser scanner can be useful for providing safety relative to a body in front of the vehicle .

When a body detected in the warning zone the bottom laser scanner can send a signal to the controller. The controller rather than halting operation could cause the drive mechanism to slow operation and could cause the light to communicate a warning signal. Such detections could also cause audible alarms to be activated.

Since the bottom laser scanner projects parallel to the ground surface objects beneath or above the plane are not detected. The use of laser scanner enables the safety zone to be extended to a third dimension because the laser scanner creates a scanning plane that projects from the laser scanner to about a front edge of the safety zone but also below the plane of the bottom laser scanner to about the ground surface. The scanning plane produced by the laser scanner is referred to as a light curtain . Like bottom scanner laser scanner also communicates signals to the controller. The controller can exercise an algorithm for causing the appropriate warning signals and drive mechanism control. For example the controller can determine what to do if the laser scanner detected a body momentarily but the bottom scanner never detected a body.

In accordance with one aspect of the present disclosure provided is a multi plane scanner support system. The system includes a bracket and a mirror block. The bracket is configured to be secured in a fixed orientation with respect to a scanner and the mirror block arranged to receive a scanning signal from the scanner and to reflect the scanning signal into a plurality of directions to create multiple scanning planes.

The mirror block can include a plurality of flat surface each flat surface arranged to reflect the scanning signal to form a different one of the multiple scanning planes.

The mirror block can include a contoured reflective surface configured to form a bent light curtain comprising the multiple scanning planes.

In accordance with another aspect of the present invention provided is a scanning system. The system includes a range scanner bracket and mirror block. The bracket is configured to be secured in a fixed orientation with respect to the range scanner. And the mirror block is arranged to receive a scanning signal from the range scanner and to reflect the scanning signal into a plurality of directions to create multiple scanning planes.

The mirror block can include a plurality of flat surface each flat surface arranged to reflect the scanning signal to form a different one of the multiple scanning planes.

The mirror block can include a contoured reflective surface configured to form a bent light curtain comprising the multiple scanning planes.

In accordance with another aspect of the present invention provided is a vehicle having a multi plane scanning system. The vehicle includes a controller operatively coupled to a drive mechanism. The multi plane scanning system includes a laser range scanner coupled to the controller a bracket configured to be secured in a fixed orientation with respect to the laser range scanner and a mirror block arranged to receive a scanning signal from the laser range scanner and to reflect the scanning signal into a plurality of directions to create multiple scanning planes. The laser range scanner is configured to receive a signal from the multiple scanning planes communicate the signal to the controller as a detection signal and the controller modifies operation of the vehicle in response to the detection signal.

The mirror block can include a plurality of flat surface each flat surface arranged to reflect the scanning signal to form a different one of the multiple scanning planes.

The mirror block can include a contoured reflective surface configured to form a bent light curtain comprising the multiple scanning planes.

The vehicle can further include a bottom scanner that projects a safety zone and is also coupled to the controller wherein the safety zone and at least one of the multiple planes intersect.

Hereinafter aspects of the present invention will be described by explaining illustrative embodiments in accordance therewith with reference to the attached drawings. While describing these embodiments detailed descriptions of well known items functions or configurations are typically omitted for conciseness.

It will be understood that although the terms first second etc. are be used herein to describe various elements these elements should not be limited by these terms. These terms are used to distinguish one element from another but not to imply a required sequence of elements. For example a first element can be termed a second element and similarly a second element can be termed a first element without departing from the scope of the present invention. As used herein the term and or includes any and all combinations of one or more of the associated listed items.

It will be understood that when an element is referred to as being on or connected or coupled to another element it can be directly on or connected or coupled to the other element or intervening elements can be present. In contrast when an element is referred to as being directly on or directly connected or directly coupled to another element there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion e.g. between versus directly between adjacent versus directly adjacent etc. .

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein the singular forms a an and the are intended to include the plural forms as well unless the context clearly indicates otherwise. It will be further understood that the terms comprises comprising includes and or including when used herein specify the presence of stated features steps operations elements and or components but do not preclude the presence or addition of one or more other features steps operations elements components and or groups thereof.

Spatially relative terms such as beneath below lower above upper and the like may be used to describe an element and or feature s relationship to another element s and or feature s as for example illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and or operation in addition to the orientation depicted in the figures. For example if the device in the figures is turned over elements described as below and or beneath other elements or features would then be oriented above the other elements or features. The device may be otherwise oriented e.g. rotated 90 degrees or at other orientations and the spatially relative descriptors used herein interpreted accordingly.

In this embodiment multi plane scanner support system and laser scanner are also mounted to mast . Vehicle includes a controller not shown to which laser scanner and bottom laser scanner are coupled. And the controller is coupled to a vehicle drive mechanism not shown that controls the operation of the vehicle. The controller is also coupled to light as described with respect to previously described.

Unlike the prior art the multi plane scanner support system is mounted relative to the scanner such a light curtain having multiple scanning planes and is generated from the single laser . That is typical lasers used scan a field of view of up to about 270 degrees. In the present invention one or more reflective surfaces of the multi plane scanner support receive the scanning signal in different portions of its scan to create multiple scanning planes and . A practical benefit of such an approach with material transport vehicles is that it enables safety zone extension and detection to the front right and left areas of the vehicle. This can be extremely useful for example when an AGV is navigating around a corner which are not covered by traditional safety zones and in .

In light curtain comprises three relatively discrete scanning planes and but in other embodiments a contoured light curtain can be formed using a contoured multi plane scanner support system .

In the illustrative embodiment laser range scanner is a S laser range scanner by SICK Inc. of Waldkirch Germany. Although the LSM S and S models are other examples of a suitable laser range scanner also by SICK Inc. The laser scanner points about 34 degrees above horizontal and about 66 inches above the ground surface. The front plane has a field ground projection of about 1100 mm from the front of the vehicle and the side planes have field ground projections of about 800 mm from the center of the front of the vehicle . These are example specific dimensions can differ depending for example on the vehicle.

In an embodiment of scanning system is shown that uses multi plane scanner support system and scanner attached to mast as discussed above. Multi plane scanner support system includes a bracket that has the laser disposed therein so that reflective surfaces attached to the bracket reflect the laser beam of laser scanner during operation. In this embodiment those reflective surfaces are comprised of three mirror blocks attached to bracket . Each mirror block includes a reflective surface that receives a scanning signal from the laser . Each of reflective surfaces is used to form a respective scanning plane. For example surface reflects the laser scanning beam along scanning plane reflective surface reflects the laser scanning beam along scanning plane and reflective surface reflects the laser scanning beam along scanning plane in .

In some embodiments two or more of bracket mirror blocks and reflective surfaces can be made of a single material or compound. I some embodiments a contoured reflective surface could be used to form a bent light curtain again having multiple planes. For example concave curves convex curve bends warps prisms etc can be used to tailor the light curtain to have the desired number and shaped plurality of scanning planes.

The present embodiments achieve multiple planes without nodding mechanisms are less expensive to make and maintain.

While the foregoing has described what are considered to be the best mode and or other preferred embodiments it is understood that various modifications can be made therein and that the invention or inventions may be implemented in various forms and embodiments and that they may be applied in numerous applications only some of which have been described herein. It is intended by the following claims to claim that which is literally described and all equivalents thereto including all modifications and variations that fall within the scope of each claim.

