GB2522616A

GB2522616A - Mechanical plant safety system

Info

Publication number: GB2522616A
Application number: GB1401050.8A
Authority: GB
Inventors: Steven Joynson; Stephen Smith; Michael Sheridan; Gavin Bryant
Original assignee: Cementation Skanska Ltd
Current assignee: Cementation Skanska Ltd
Priority date: 2014-01-22
Filing date: 2014-01-22
Publication date: 2015-08-05
Anticipated expiration: 2034-01-22
Also published as: GB2522616B; GB201401050D0

Abstract

A mechanical plant 100 has a controllable movable element 106 such as an auger, drill string, bucket or hopper. A safety system uses a camera 120 mounted to the mechanical plant to generate an image of a region 140 near to the controllable element. The processor 122 is configured to determine, based on the image of the region, the presence of a hazard 142 (e.g. person) in the region, and output a signal indicative of the presence of the hazard, preferably as an indication on a user interface 130. The camera is ideally mounted in an elevated position, and may generate a plurality of images where the presence of the hazard is determined by comparing two or more image to identify movement. The presence of a hazard may also be determined by analysing the footprint of an object in the image(s). The system may employ a plurality of cameras to cover many regions around the plant, each image received from each of the cameras being displayed on the UI. The controllable element may be deactivated following the detection of a hazard, preferably after a delay.

Description

Mechanical Plant Safety System

Field of the Invention

The invention relates to mechanical phmt. In particular. the invention relates to a salety system for monitonng hazards in a region in proxi nuty to a mechanical plant.

Backuroulld of the Invention A wide range of mechanica' plant, such as drilling rigs, excavators and loaders, are used throughout the construction industry. These mechanical plant have moving parts, such as pivoting or rotating augers, drill strings, buckets or hoppers, which can be hazardous to construction workers and members of the public in the vicinity, who are at risk of being injured or killed if they accidently come into contact with them.

It is known to place one or more light curtains around mechanical plant to detect the presence of hazards, such as people. approaching the mechanical plant. The light curtain works by projecting a beam of Ught onto a sensor. If the beam of light is broken, for example. by a person walking through thc beam, the sensor detects the fact that the beam of light is no longer reaching the sensor and can indicate that the moving parts on the mechanical plant should be shutdown, preventing the person from potentially being injured.

A problem with the light curtain approach is that the light beam may be broken not just by a person wallung into the beam, but may also be broken by other objects passing through the beam, where these other objects do not warrant shutting down the mechanical plant. For example, the light beam may be blocked by a wall or another vehicle, or the light beam may be blocked by dust or smoke, which may lead to the mechanical plant being shutdown unnecessarily.

It would, therefore, be advantageous to find an alternative safety system for a mechanical plant which overcomes the problems mentioned above.

Summary of the Invention

According to a first aspcct of thc invention, thcrc is provided a mechanical plant S comprising a controllable clemcnt and a safety system, as sct forth in claim 1.

The fact that the processor is configured to determine, based on the image of the region, a presence of a hazard in the region means that the safety system is able to distinguish between different kinds of hazard, so that the safety system is more likely to be triggered only by genuine hazards, such as people. The fact that the processor is further configured to output a signal indicative of the presence of the hazard means that an operator can bc alerted to the fact that a potential hazard is in close proximity to the controllable element, so that the operator can take action if necessary.

The mechanical plant may be a piling or drifling rig, an excavator or a thader, for example. The controllable element may be any moving, rotating or pivoting mcmber on the plant, such as, an auger, a boom, a hopper, a jib, a mast, a drilling tool, a pihng tool or a bucket.

The camera may be mounted in an elevated position on the mechanical plant. The camera may be configured to look down at the ground in order to generate an image of the region comprising a substantially plan view of the region, which improves the ability of the camera to spot hazards approaching the controllable dement.

The camera may be configured to generate a further image of the region. The presence of the hazard may be determined by detecting an object in the image and the further image, and determining that the object has moved between the image and the further image. This allows for moving hazards, such as people. to be discriminated from fixed or stationary objects, such as walls or parked vehicles.

The image and the further image may comprise respective first and second frames from a video.

The processor may be configured to determine the hazard based on a footprnt of an object in the image. This allows for hazards, such as people. to be discriminated from objects, such as walls or other mechanical plant, br example, by setting a maximum footprint for a hazard beyond which is it known that the footprint of the object is too S large to represent a person. Alternatively, or additionally, a minimum footprint can be set so that small objects, such as blowing leaves, can be ignored and will not cause a false hazard.

A plurality of cameras may be mounted to the mechanical plant. Each camera of the plurality of cameras may be configured to generate one or more images of one of a plurality of regions in proximity to the controllable element. The processor may he further configured to determine, based on the one or more images of each of the regions, a presence of a hazard in one or more of the regions. This allows multiple regions around the mechanical plant to be monitored for the presence of hazards, for example, to monitor the whole, or a portion, of the perimeter around the mechanical plant.

The processor may he further configured to display, on a user interlace, the image or images of some, or all, of the plurality of regions. The presence of the hazard may he indicated by modifying an aspect of the image. or images, of a region where the presence of a hazard is determined. For example, the image, or each of the images, where the presence of a hazard is determined may be provided with one or more of: a coloured, highlighted or flashing border; an enlarged image: or an overlay.

The processor may be configured to instruct the mechanical plant to deactivate the controllable element after a period of time has elapsed from the detenrdnation of the presence of a hazard.

The processor may he configured to receive a request, during the period of time, to prevent the deactivation of the controllable element. This provides an operator, who is monitoring the user interface for the presence of hazards, a period of time to decide whether or not a determined hazard represents an actual hazard, such as a person, which has entered the region. If the operator considers there to be no actual hazard present, the operator may indicate during the period of time that no hazard is present in the region. for example, by operaling a control, such as a button, on the user interlace. If die operator indicates that no hazard is present. the mechanical plant will be prevented from shutting down, thereby reducing or eliminating unnecessary S shutdowns.

The processor may he further configured to store a log of determined hazards.

The processor may be configured to determine the presence of a hazard in a subregion of the region. By selecting a subregion. oniy movement within this subregion will be considered when dctermining the presence of a hazard, which allows for a region where false hazards are likely to occur to be excluded, for example, a region where vehicles are known to be moving could be excluded. The subregion may be determined based on an operator selection. The operator may select the subregion using the user interface. icr examp'e, by drawing the desired subregion on the image displayed on the user interface.

The safety system may he further configured to deactivate the controllalie element in response to receiving an indication to deactivate the controllable clement. This provides the safety system with an emergency stop' which substantially instantaneously deactivates the controllable element, and optionally stops any other moving parts on the mechanical plant. This emergency stop function may be implemcntcd as a button on the user interface, or as a physical button or switch hardwircd to the mechanical plant, where the operator presses the button if they perceive or are alerted to the presence of a hazard in the region, thereby stopping the mechanical plant and preventing injury or death to a person. or damage to property.

According to another aspect of the invention, there is provided a safety system compnsing: a camera for generating an image of a region to he monitored; and a processor configured to: determine, based on the image of the region, a presence of a hazard in said region; and output a signal indicative of the presence of the hazard.

In exemplary embodiments, the camera is configured to generate a phirality of images of the region; and the presence of the hazard is determined by comparing two or more of said plurality of images. in order to identify movement of an object into or within said region.

In exemplary embodiments, the processor determines the presence of the hazard based on a footprint of an object in the or each image.

In exemplary embodiments, the safety system further comprises a user interface, wherein the user interface is configured to: receive the signal indicative of the presence of the hazard; and display an indication of the presence of the hazard.

IS

In exemplary embodiments, the safety system comprises a plurality of cameras, each configured to generate one or more images of one or more regions; and wherein the processor is further conligured to determine, based on the one or more images of each of the regions, a presence of a hazard in one or more of the regions.

In exemplary embodiments, the processor is further configured to display the one or more images of each of the plurality of regions on a user interface.

In exemplary embodiments, the presence of the hazard is indicated by modifying an aspect of the one or more images of the region. or each of the regions. in which the presence of the hazard is determined.

In exemp'ary embodiments, the safety system is configured to generate a command (e.g. for deactivating machinery) alter a period of time has elapsed from the determination of the presence of the hazard.

In exemplary embodiments, the safety system is configured to receive a request, during the period of time, to prevent generation of said command.

In exemplary embodiments, the request is conveyed via operation of a control on said S user interface.

In exemplary embodiments, the processor is further configured to store a log of determined hazards.

In exemplary embodiments, the processor is configured to determine the presence of a hazard in apredefined subregion of the image.

In exemplary embodiments, the predefined subregion is determined based on an operator selection. e.g. conveyed via said user interface.

IS

In exemplary embodiments, the safety system is further configured to issue a command (e.g. for deactivating machinery) in response to a user input, e.g. via a control element in communication with the processor or user interlace.

The safety system will have advantageous application with various foims of mechanical plant (e.g. a piling or drilling rig, an excavator or a loader), especially those types of mechanical plant having a controllable element, such as a moving, rotating or pivoting member on the plant, e.g. an auger, a boom, a hopper, a jib. a mast, a drilling tool, a piling tool or a bucket.

Brief Description of the Drawins

The invention shall now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic of a mechanical plant incorporating a safety system according to an embodiment of the invention, where the mechanical plant is specifically a drilling rig; Figure 2 is a schematic of a mechanical plant incorporating a safety system according to an embodiment of the invention, where the mechanical plant is a piling rig; Figure 3 is a schematic illustration of a user interface, such as the user S interface shown in Figure 1 or Figure 2; and Figure 4 is a schematic illustration of an image with subregions.

Detailed Description of the Drawings

Figure 1 illustrates a mechanical plant in the form of drilling rig 100. The drilling rig includes a mast 102 mounted on a tracked unit 104. The mast 102 supports a drill string, indicated by dotted line 106. The or entation of the dotted line 106 corresponds to the normal operative orientation of the drill string. In this embodiment, the drilling rig 100 includes a rotation head 108. which is operable to control rotation of the (frill string 106 and is intended to he driven downwards from an devated position (shown in outline only). in order to drill a hole for a deep foundation, for example, using an auger at the lower end ol the drill string 106.

The drilling rig 100 includes a safety system, for preventing or at least limiting access to the drill string 106 when the drill string 106 is operative. k general terms, the safety system includes a camera 120 mounted to the drilling rig 100. The camera 120 is coupled to a processor 122 and the processor 122 is coupled to a user interface 130.

The camera 120 is configured to generate images of a region 140 in proximity to the drill string 106. The images are displayed on a user interface 130 which an operator may monitor.

The processor 122 receives and analyses the images from the camera 120 to monitor br moving objects, such as person 142. moving into or through the region 140. For example, the processor 122 may detect movement by receiving an image and one or more further images at one or more respective later times, and the processor 122 may compare these images to look for an object which has moved between the images, or to look for a new object that has appeared in the images. If the processor 122 detects movement in the images, the processor 122 indicates the presence of the hazard on the user interface 130.

The camera 120 is mounted to the top of mast 102 so that the camera 120 is in an S elevated position on the drilling rig 100. In this elevated position. the camera 120 is looking down at the ground in order to generate a substantially plan view of the region 140, which improves the ahility of the camem 20 to spot person 142 approaching the drill string 106.

Although Figure 1 shows just one camera 120, any number of cameras 120 could be mounted to the drilling rig 100. Each camera 120 is configured to generate images of a respective region. The processor 122 is further configured to determine, based on the images of each of the regions, whether a hazard is present. in any of the regions, based on whether movement is detected in the image of each region.

Figure 2 illustrates another mechanical plant which could benefit from a safety system. In Figure 2, the mechanical plant is a piling rig 200 which includes a mast 202 mounted on a (racked unit 204. The mast 202 supports a Kelly tool drive 205 which is attached to a digging tool 208 controllable between a raised position (e.g. as illustrated) and a lowered position (e.g. as shown in outline).

The piling rig 200 includes a safety system, which is the same as the safety system dcscribcd in relation to Figure 1.

Figure 3 shows a schematic of a user interface 130. The user interface 130 is displaying image 132a from camera 120 which is monitonng region 140 shown in Figure 1. The user interface 130 is also displaying image 132b from a further camera monitoring a further region not shown iii Figure 1.

As mentioned above, the processor 122 has determined the presence of a hazard in the form of person 42 who is moving around region 140. The presence of person 42 is indicated in the user interface by the border 138 around image 132a. The border 138 draws the operator's attention to image 132a so that the operator knows that person 142 has been detected in region 140.

In response to the presence of person 142 in region 140, the processor 122 starts a S countdown, for example, a less than one second countdown. If the operator is happy that the determined hazard, person 142, is not a problem, the operator can accept the hazard by selecting the accept hutton 134. The operator may do this, for example. if the operator knows that the person 142 is a trained construction worker who the operator expects to be in the region 140. Alternatively, the operator may accept the hazard if the determined hazard was a false hazard.

If the operator fails to accept the hazard within the countdown period, then at the end of the countdown period the processor 122 will instruct the drilling rig 100 to deactivate the drill string 106.

If. on being alerted to the person 142, the operator realises that the person 142 is in danger. the operator can immediately stop the drill string 106 before the end of (lie countdown period by hitting the stop button 136 on (lie user interface.

Figure 4 shows image 132a of region 140, where the image 132a has been divided into subregions. In this example, the image 132a is divided into nine subregions 133a- 133i. The processor 122 may be configured to determine the presence of a hazard in only one subregion of the image 132a. In this example, the processor 122 only determines the presence of a hazard occurring in subregion 133e, and as the processor 122 has determined the presence of a hazard, in the form of person 142, in subregion 133e, the processor 122 has indicated the presence of the hazard in the subregion 133e by placing border 138 around subregion 133e.

By selecting a subregion. such as subregion 133e, offly movement within (he subregion 133e will he considered when determining the presence of a hazard, which allows for the exclusion of a subregion or subregions where false hazards are likely to occur, for example, a subregion where vehicles are known to be moving could be excluded.

The subregion may be determined based on an operator selection. For example, the operator may select the subregion using the user interlace 130, for example, by drawing the desired subregion on the image displayed on the user interface, or by S selecting one or more preconfigured subregions.

Although the invention has been described with certain preferred features, the skilled person will appreciate that various modifications could be made.

For example, although the invention has been described in relation to a drilling rig 100, the invention is equally applicable to any kind of mechanical plant, such as, an excavator or a loader, which has moving parts which might potentially hit or collide with a person causing injury or death, or damage to property. Although the controllable element has been described in terms of a drill string 106, the controllable element maybe any moving, rotating or pivoting member, such as, an auger, a boom, a hopper, or a bucket, which might potentially hit or collide with a person causing injury or death, or damage to property.

Although the camera 120 has been described as capturing images, the camera 120 could also capture video and the images could be frames from the video.

Although the image l32a in Figure 4 has been described as being divided into nine subregions 133a-133i, the image couM he divided into any number of subregions, where cach of the subregions may bc the same or different sizes. Thc processor 122 may be configured to determine the presence of a hazard in two or more subregions of the image 132.

Any number of cameras 120 may be provided at any location on the mechanical plant.

Sufficient cameras 120 maybe provided so as to monitor the lull perimeter around the mechanical plant, or allematively, just a portion of the perimeter of the mechanical plant may he monitored.

All of the cameras 120 may be mounted to the mast 102, or other high point on the mechanical plant, so that the cameras 120 obtain a plan view. alternatively, some cameras may he mounted to die mast 102, while other cameras 120 are mounted iii alternative positions so as to obtain a different view point of the respective region.

S

Although the emergency stop function has been illustrated as being implemented as a button on the user interface, the emergency stop function could, instead, he implemented by a physical button or switch hardwired to the mechanical plant.

Although the user interface 130 has been illustrated displaying two images 132a and 132h simultaneously, the user interface 130 may display any number of images. The user interface 130 could show images from all of the cameras simultaneously. or only from one or a selected number of cameras which may be selectable by an operator, for example, using additional buttons on the user interface 130.

Although the user interface 130 had been illustrated as indicating the presence of a hazard using a border 138, the user interface 130 coukl indicate the presence ol a hazard by any means which bring the hazard to the attention of the operator. For example, hy providing a highlighted or flashing border, or by enlarging the image. or by providing m overlay, or by providing an audible alert.

Claims

Claims 1. A mechanical plant comprising a controllable element and a safety system, wherein the safety system comprises: a camera mounted to the mechanical plant. the camera configured to generate an image of a region in proximity to the controllable element; and a processor configured to: determine, based on the image of the region, a presence of a hazard in the region; and output a signal indicative of the presence of the hazard.
2. The mechanical plant of claim I, wherein the camera is mounted in an elevated position on die mechanical plant such that die image ol the region comprises a substantially plan view of the region.
3. The mechanical plant of either of claims 2 or 3, wherein: the camera is configured to generate a p'urality of images of the region: and the presence of the hazard is determined by comparing two or more of said plurality of images, in order to identify movement of an object into or within said region.
4. The mechanical plant of any preceding claim, wherein the processor determines the presence of the hazard based on a footprint of an object in the or each image.
5. The mechanical plant ol any preceding claim, further comprising a user interface, wherein the user interface is configured to: receive the signal indicative of the presence of the hazard; and display an indication of the presence of the hazard.
6. The mcchathcal plant of any preceding claim, further comprising: a plurality of cameras mounted to the mechanical plant. wherein each camera of the plurality of cameras is configured to generate one or more images of one of a plurality of regions in proxinilty to the controllable element; and wherein the processor is further configured to determine, based on the one or more images of each of the regions, a presence of a hazard in one or more of the regions.
7. The mechanical plant of claim 6, wherein the processor is further configured to display the one or more images of each of the plurality of regions on a user interface.
8. The mechanical plant of claim 7, wherein the presence of the hazard is indicated by modifying an aspect of the one or more images of the region. or each of the regions, in which the presence of the hazard is determined.
9. The mechanical plant of any preceding claim, wherein the safety system is configured to instruct the mechanical plant to deactivate the controllable element alter a period of time has elapsed from the determination of the presence of the hazard.
10. The mechanical plant of claim 9, wherein the safety system is configured to receive a request. during the period of time, to prevent the deactivation of the controllable element.
11. The mechanical plant of claim 10, wherein the request comprises an operator operating a control on a user interface.
12. The mechanical plant of any preceding claim, wherein the processor is further configured to store a log of determined hazards.
13. The mechanical plant of any preceding claim, wherein the processor is configured to determine the presence of a hazard in a predefined subregion of the image.
14. The mcchathcal plant of claim 13, wherein the predefined subregion is determined based on an operator selection.
15. The mechanical plant of any preceding claim, wherein the safety system is further configured to deactivate the controllable element in response to receiving a request to deactivate the controllable element.
16. The mechanical plant of any preceding claim, comprising a tracked unit and a controllable element mounted for movement with said tracked unit.
17. A mechanical p'ant or safety system substantially as described herein or with reference to any of the accompanying drawings.