Information
-
Patent Grant
-
6202013
-
Patent Number
6,202,013
-
Date Filed
Thursday, January 15, 199826 years ago
-
Date Issued
Tuesday, March 13, 200123 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
-
CPC
-
US Classifications
Field of Search
US
- 701 50
- 037 348
- 037 414
- 702 94
- 212 276
- 212 277
- 212 278
- 212 279
- 212 280
- 212 281
- 212 294
- 212 301
- 212 302
- 212 304
- 212 306
- 212 195
- 212 196
-
International Classifications
-
Abstract
A monitoring system is provided for monitoring positioning and stability of an articulated boom system The articulated boom system includes an articulated boom, having one or more boom sections, extending from a base, along with one or more outriggers extending from the base. The monitoring system includes a load sensor placed on a leading end of the articulated boom, a boom position sensor placed on the leading end, an outrigger sensor placed on the outrigger(s) and a computer. The load sensor delivers a signal to the computer indicative of the load on the leading end The boom position sensor delivers information to the computer indicative of the position of the leading end with respect to the base. The outrigger sensor delivers a signal to the computer indicative of the extension of the outrigger(s) from the base. The computer determines the position of the articulated boom based upon the sensed position of the leading end. Further, the computer monitors the of the stability of the articulated boom system based upon the sensed load, articulated boom position, outrigger(s) extension and predetermined data.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a monitoring system for monitoring operation of an articulated boom. More particularly, it relates to a monitoring system for monitoring position and stability of an articulated boom system which includes a base, an articulated boom and at least one outrigger.
Articulated boom systems are typically used to lift and position loads, such as pumping implements, equipment, work platforms, workers, etc., at particular elevations. For example, in concrete pumping applications, an articulated boom system is used to position a concrete distributing hose at a distant work site, normally located well off of the ground. Similarly, where a construction project requires delivery of concrete along a lengthy, above ground horizontal path, such as tunnel lining, an articulated boom system is used. Even further, articulated boom systems can maneuver the load along a relatively continuous plane. This attribute is important for many material distribution applications where an articulated boom is moved along a ceiling wall, floor, etc. while certain material such as concrete, is distributed. Through recent development, some articulated boom systems have vertical and horizontal ranges on the order of fifty meters. Articulated boom systems normally include a base such as a truck to which an articulated boom with one or more boom sections is attached, a rotational actuator mechanism such as a rack and pinion mechanism for rotating the boom, and outriggers or support legs retractably extending (e.g., by telescoping or pivoting) from the base for stabilizing the articulated boom system. Each boom section has a corresponding actuator which supports the boom section as well as any load supported by that boom section. Typically, the actuators are hydraulic piston/cylinder assemblies. Forces generated by the actuators, lifted loads, or obstacles making contact with the articulated boom, act upon articulated boom components during operation of the articulated boom system. The maximum loads or forces that the actuators, boom sections and other articulated boom system components are structurally designed to withstand are generally known by the articulated boom system manufacturer. This information may be translated into maximum loads or forces that the overall articulated boom system can support or withstand without exceeding design constraints.
Articulated boom System are frequently subjected to work conditions where the articulated boom supports loads and experiences forces that may exceed design limitations. The base serves as a strong support for the articulated boom, allowing movement to a number of positions without tipping. In other words, the articulated boom creates a moment force which is offset by the base. In addition, the outriggers are used to further stabilize the articulated boom system. The outriggers are normally deployed to their fullest extension so as to provide maximum balancing support for the entire articulated boom system. By using outriggers, the articulated boom can be maneuvered to maximize the horizontal and vertical positions without tipping. Typically, a boom operator becomes accustomed to maneuvering the articulated boom to these maximum extension positions, with the outriggers fully deployed.
At times, however, the work site does not allow for full outrigger extension. For example, when working near a heavily used street or along side a hill, one or more of the outriggers may not be able to fully extend or even extend at all. A problem can occur if the boom operator, who is otherwise accustomed to maneuvering the articulated boom to certain vertical and horizontal positions with the outriggers fully extended, forgets that the outriggers are not fully extended and attempts to maneuver the articulated boom to a position he or she has operated at in the past. However, without the extra balancing support provided by the outriggers, the force created by the articulated boom and its attached load becomes too great, causing the entire articulated boom system to tip. In this situation, potentially catastrophic results can occur with harm to human life, nearby facilities, and the articulated boom system itself.
Additional operation safety concerns arise at crowded work sites. Construction work sites often involve a greater number of possible physical obstacles, such as trees, overhead power lines, etc. The boom operator must constantly remain aware of these obstacles whenever present to avoid directing the articulated boom into contact with an obstacle. This may be a demanding task at times due to the location of the obstacle (eg. the exact location of a high power line is difficult to judge), other activities requiring the boom operator's attention, etc. Contact with certain obstacles, such as trees or buildings, may damage the articulated boom system or cause it to tip. Even worse, some obstacles, such as power lines can cause severe injury or death to the operator if contacted. Thus, safe operation of an articulated boom system requires frequent monitoring of the position of the articulated boom along with the location of any obstacles.
Therefore, in view of the above problems associated with articulated boom system operation, a substantial need exists for a monitoring system for monitoring the position and stability of an articulated boom system, and warn or otherwise prevent the articulated boom from moving into a tipping situation, or contacting work site obstacles.
BRIEF SUMMARY OF THE INVENTION
The present invention provides an articulated boom monitoring system for monitoring the position and stability of an articulated boom system. In the preferred embodiment, the monitoring system is based upon sensing a load on a leading end of the boom assembly, the distance (both vertical and horizontal) of the leading end from the base, and the extension, (if any) of various outriggers.
The articulated boom monitoring system of the present invention monitors operation of an articulated boom system having a base from which an articulated boom, having one or more sections, extends, and at least one outrigger attached to the base for stabilizing the articulated boom. The preferred articulated boom monitoring system includes a load sensor, a boom position sensor, an outrigger sensor and a controller. The load sensor is placed on a leading end of the articulated boom for sensing a load and producing a signal representative of the sensed load. Similarly, the boom position sensor senses a position of the leading end of the articulated boom with respect to the base and supplies a boom signal representative of the sensed leading end position. The outrigger sensor senses the extension, if any, of the outrigger from the base and supplies an outrigger position signal representative of the sensed outrigger position. The various signals are received and stored by the controller.
The controller is preprogrammed with information related to operation of the articulated boom system in question. More particularly, the controller is programmed with information related to stability of the articulated boom system at different moments generated by the articulated boom and different outrigger positions. The controller constantly receives the various signals representative of the load on the leading end of the articulated boom and the positions of the articulated boom and the outriggers. The controller uses this information to calculate the actual moment created by the articulated boom on the articulated boom system. The controller then determines whether the base and the outriggers, if any, can support the existing moment created by the articulated boom. In a preferred embodiment, when the controller determines that the boom is moving into a potential hazardous situation (colliding with an obstacle e.g., tipping), a warning signal is delivered.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is a perspective view of an articulated boom system having a monitoring system in accordance with the present invention.
FIG. 2
is a block diagram of a monitoring system for an articulated boom system in accordance with the present invention.
FIG. 3
is a perspective view of an alternative embodiment of an articulated boom system in accordance with the present invention.
FIG. 4
is a block diagram of an alternative embodiment of a monitoring system for an articulated boom system in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A. Articulated Boom System
10
FIG. 1
shows a perspective view of an articulated boom system
10
incorporating a monitoring system of the present invention. The articulated boom system
10
includes an articulated boom
12
and a truck
14
. The articulated boom
12
includes a turret
16
, a first boom section
18
, a second boom section
20
, a third boom section
22
, a first actuator assembly
24
, a second actuator assembly
26
and a third actuator assembly
28
. The truck
14
acts as a base and includes hydraulically driven outriggers or support legs
30
,
32
,
34
and
36
which are used to stabilize the articulated boom system
10
against the weight of the articulated boom
12
and any load carried by the articulated boom
12
, such as a hose
38
shown in FIG.
1
. In addition to these standard components, the articulated boom system
10
includes a monitoring system some components of which are shown in FIG.
1
.
The monitoring system includes a load sensor
40
, a boom position sensor
42
and outrigger position (extension) sensor
44
. The load sensor
40
is preferably located on a leading end
46
of the articulated boom
12
. Similarly, in the preferred embodiment, the boom position or sensor
42
is located on the leading end
46
. Finally, each of the outriggers
30
,
32
,
34
and
36
has an associated outrigger extension sensor
44
.
The turret
16
of the articulated boom
12
is mounted on the truck
14
to support the boom sections
18
-
20
and
22
. In preferred embodiments, the turret
16
is rotated by a rotational actuator or drive mechanism such as a rack and pinion mechanism or a motor driven gear mechanism to rotate the articulated boom
12
. Although typically the rotational drive mechanism is hydraulically driven, the turret
16
can be rotated by means of other types of drive mechanisms as well.
A bottom end
48
of the first boom section
18
is pivotally connected to the turret
16
. A second end of the first boom section
18
is pivotally connected to a fist end of the second boom section
20
. Likewise, a second end of the second boom section
20
is pivotally connected to a first end of the third boom section
22
, which terminates with the leading end
46
. Although in the embodiment shown in
FIG. 1
the articulated boom
12
has three boom sections
18
-
20
and
22
, in other preferred embodiment the articulated boom
12
can include any number of boom sections, with a minimum of one boom section. Regardless of the number of boom sections, the leading end
46
, as used throughout this specification, is defined as the free end of the last boom section (the third boom section
22
in FIG.
1
).
The first actuator assembly
24
is connected to the turret
16
and the first boom section
18
for moving the first boom section
18
relative to the turret
16
. The second actuator assembly
26
is connected to the first boom section
18
and the second boom section
20
for moving the second boom section
20
relative to the first boom section
18
. Similarly, the third actuator assembly
28
is connected to the second boom section
20
and the third boom section
22
for moving the third boom section
22
relative to the second boom section
20
.
In preferred embodiments, the articulated boom
12
is a hydraulic boom system and actuator assemblies
24
-
26
and
28
are hydraulic actuator assemblies. For example, in the preferred embodiments shown in
FIG. 1
, the articulated boom
12
is a hydraulic boom and the actuator assemblies
24
,
26
and
28
are hydraulic piston/cylinder assemblies. However, it should be noted that the actuator assemblies
24
,
26
and
28
can be any other type capable of producing mechanical energy for exerting forces sufficient to support loads on the boom sections
18
,
20
and
22
and for making the boom sections
18
,
20
and
22
move relative to one another and relative to the turret
16
. Thus, the actuator assemblies
24
,
26
and
28
can be a type of hydraulic actuator other than a piston/cylinder assembly. Also, the actuator assemblies
24
,
26
and
28
can be pneumatic, electrical, or other types of actuators instead of being hydraulic actuators.
The load sensor
40
is positioned on the leading end
46
of the articulated boom
12
. The load sensor
40
can be a strain gauge which measures the weight or load placed on the leading end
46
. Alternatively, other load sensors are equally applicable, such as a pressure sensor placed on the third actuator assembly
28
. Based upon known information, including the length and weight of the third boom section
22
, the sensed pressure within the third actuator assembly
28
can be used to calculate the overall load on the leading end
46
.
Similar to the load sensor
40
, the boom position sensor
42
is located on the leading end
46
of the articulated boom
12
. The boom position sensor
42
provides accurate information regarding the position of the leading end
46
with respect to the bottom end
48
of the first boom section
18
, or the truck
14
. In a preferred embodiment, the boom position sensor
42
is a Global Positioning System (GPS) system (which preferably operates in a differential mode) to achieve high precision position measurement. GPS was designed by the Department of Defense to fulfill precise military navigational requirements. The system consists of twenty-four artificial satellites in orbit 11,000 miles above the earth. A GPS receiver receives a signal from the satellites and through a series of calculations, the GPS system measures the exact distance between the satellites and the GPS receiver. Using the distance from the satellite to the receiver and knowing the exact position of the satellite, the ground position can then be determined by trigonometrically intersecting the distances from a minimum of four satellites simultaneously. The potential for GPS technology is limitless. The accuracy is becoming very precise on the order of 1-2 centimeters (0.39-0.78 inches), in a differential sensing mode. On slow moving equipment, accuracy is increased. The slower the movement of the GPS sensor
42
, the more accurate the position can be measured.
The outrigger extension sensors
44
sense a parameter related to the actual extension of each of the outriggers
30
,
32
,
34
and
36
. For example, where the outriggers
30
-
36
are hydraulically controlled, the outrigger extension sensors
44
are preferably pressure sensors which sense hydraulic pressure in the hydraulic cylinder of each of the outriggers
30
-
36
. The pressure in a particular outrigger hydraulic cylinder is indicative of the total extension of that outrigger
30
-
36
. Alternatively, each outrigger extension sensor
44
can sense the angle that its respective outrigger
30
-
36
is pivoted away from the truck
14
and, with the overall length of the outrigger
30
-
36
being known, provides a parameter which is indicative of the overall outrigger extension. In still another embodiment in which telescoping outriggers are used, outrigger sensor
44
can sense linear movement of the outrigger to determine outrigger position or extension. Preferably, the number of outrigger extension sensors
44
will coincide with the number of the outriggers. Thus, when only one outrigger is present, only one outrigger sensor
44
is required.
The above mentioned sensors
40
,
42
,
44
all provide information directed to stability of the articulated boom system
10
, which is a function of a moment force imparted on the truck
14
. The moment created by the articulated boom
12
is basically a function of the load on the leading end
46
, the horizontal and vertical position of the leading end
46
with respect to the truck
14
, and the weight and position of the first boom section
18
, the second boom section
20
and third boom section
22
. Therefore, the moment generated by the articulated boom
12
varies depending upon the location of the leading end
46
with respect to the truck
14
. Given the fact that modern articulated booms can reach vertical heights and horizontal lengths of fifty meters, the moment generated by the articulated boom
12
can vary immensely, regardless of the load on the leading end
46
.
The weight of the truck
14
acts as a balancing force or ballast to the moment created by the articulated boom
12
. When the turret
16
is attached to a front portion of the truck
14
(as shown in FIG.
1
), the truck
14
itself provides a greater balancing force when the leading end
46
is positioned directly in front of or directly behind the truck
14
. Conversely, the truck
14
provides less of a ballast when the article boom
12
, and therefore the leading end
46
, is rotated to either side of the truck
14
. In other words, the weight of the truck
14
is such that a greater moment can be accommodated (and thus a greater articulated boom
12
extension) when applied either directly in front of or behind the truck
14
.
To provide further balancing support to the truck
14
, the outriggers
30
-
36
are utilized. The outriggers
30
-
36
add a wider base of support to the truck
14
. Further, the outriggers
30
-
36
stabilize the truck
14
when the articulated boom
12
is maneuvered to either side of the truck
14
. When deployed, two of the outriggers
30
,
32
act to prevent tipping when the leading end
46
, and therefore the moment created by the articulated boom
12
, is to the left of the truck (as shown in
FIGS. 1
) while the other two outriggers
34
,
36
act to prevent tipping when the leading end
46
is positioned to the right of the truck
14
(as shown in FIG.
1
). Moreover the ourigger
30
-
36
end from the truck
14
, the greater the support provided.
As system
10
is prepared for operation, truck
14
must be leveled. Preferably, truck
14
is leveled to within 3° or less of horizontal using they hydraulicly movable fact of outriggers
30
,
32
,
34
and
36
to raise or lower corners of truck
14
as necessary. Inclinometers may be used, for example, to aid in the operator in the leveling process.
With parameters related to the load, boom position, and outrigger extension(s) values sensed, the overall stability of the articulated boom system
10
can be monitored. Although the present invention is equally applicable to articulated boom systems
10
using actuator assemblies
24
-
28
other then hydraulic piston/cylinder assembles, for ease of illustration, the descriptions of preferred embodiments are sometimes limited to booms with hydraulic piston/cylinder actuator assemblies. However, this is not intended to limit the present invention to articulated boom systems
10
with hydraulic piston/cylinder actuators
24
-
28
.
B. Monitoring System
100
FIG. 2
shows a preferred embodiment of the monitoring system
100
. The monitoring system
100
monitors the operation and overall stability of the articulated boom system
10
and warns a user of possible tipping situations. The monitoring system
100
includes the load sensor
40
, the boom position sensor
42
, the outrigger extension sensors
44
, a computer
102
, an input device
104
and an output device
106
. The load sensor
40
, the boom position sensor
42
, the outrigger extension sensors
44
, the input device
104
and the output device
106
are all connected to the computer
102
.
As previously described, the load sensor
40
sense the load on the leading end
46
of the articulated boom
12
(shown in
FIG. 1
) and provides a signal to the computer
102
which is indicative of this load. The boom position nor
42
senses the vertical and horizontal location of the leading end
46
(shown in
FIG. 1
) and provides a signal to the computer
102
which is indicative of this position. Finally, the outrigger extension sensors
44
monitor the extension (position) of each of the outrigger
30
-
36
(shown in
FIG. 1
) and provide signals to the computer
102
which are indicative of these extensions.
In preferred embodiments, the computer
102
is a microprocessor-based computer including associated memory and associated input/output circuitry. However, in other embodiments, the computer
102
can be replaced with a programmable logic controller (PLC) or other controller or equivalent circuitry.
The input device
104
can also take a variety of forms. In one preferred embodiment, the input device
104
is a keypad entry device. The input device
104
can also be a keyboard, a remote program device, a joystick, or any other suitable mechanism for providing information to the computer
102
.
The output device
106
is preferably any of a number of devices. For example, the output device
106
can include a display output such as a cathode ray tube or a liquid crystal display. The output device
106
can also be an alarm device, such as a bell, flashing light etc., which acts to warn an operator of a potential tipping situation. Finally, the output
106
can be a device designed to “shut down” the articulated boom
12
(shown in
FIG. 1
) and prevent it from maneuvering into a tipping position. In this situation, the output
106
can be an hydraulic control circuit which prevents any of the actuator assemblies
24
-
28
(shown in
FIG. 1
) from maneuvering until overridden by the operator.
In preferred embodiments of the present invention, one or more predetermined maximum allowable moment values are stored in the memory of the computer
102
. This predetermined data is related to the operating parameters of the particular articulated boom system
10
. More particularly, the predetermined data details the acceptable loads (or moments) that can be created by the articulated boom
12
without causing the articulated boom system
10
to tip. As previously described, with respect to
FIG. 1
, the articulated boom system
10
will tip when the moment applied by the articulated boom
12
exceeds the stabilizing support of the truck
14
and the outriggers
30
-
36
. Therefore, based upon the known support provided by outriggers
30
-
36
, predetermined data regarding the maximum supportable moment at any position of the articulated boom
12
with respect to the truck
14
can be calculated and entered into the computer
102
. In other words, for a particular articulated boom system
10
, the truck
14
has a general known weight and size. Further, the outriggers
30
-
36
are of a known size and extend from the truck
14
to known positions. With this information, it is possible to calculate the maximum force the truck
14
and outriggers
30
-
36
can offset when applied by the artic boom
12
at the turret
16
. Notably, this maximum allowable moment will change depending upon the position of the leading end
46
, and thus the direction of the moment created by the articulated boom
12
.
Depending upon the positioning of the outriggers
30
-
36
, the truck
14
and the outriggers
30
-
36
may support a larger load centered toward the front of the truck
14
versus a load centered on either side of the truck
14
. In this way, maximum supportable moment forces are preferably calculated for a number of rotational positions (approximately every 5 degrees) of the turret
16
. To simplify these calculations, it can be assumed that the support provided by the fully extended outrigger
30
-
36
is virtually identical for any position of the turret
16
and thus the articulated boom
12
, therefore requiring only a single maximum allowable moment calculation.
In addition to maximum allowable moment data for various rotational positions of the turret
16
with fully extended outriggers
30
-
36
, predetermined data regarding the maximum allowable moment when the outriggers
30
-
36
are less than fully extended are also calculated and entered into the computer
102
. As previously described, the outriggers
30
-
36
act to stabilize the articulated boom system
10
. As the outriggers
30
-
36
extend further from the truck
14
, they provide more ballast or support to the articulated beam system
10
(depending upon the position of the leading end
46
).
Optimally, it is desirable to determine the maximum allowable moment for any position of any of the outriggers
30
-
36
. However, for purposes of simplicity, only the maximum allowable moment at various positions of the turret
16
need to be calculated. Preferably, these calculations would be for when the outriggers
30
-
36
are not extended, extended one-third of their maximum, extended two-thirds of their maximum and fully extended. Notably, these values should be determined for a number of outrigger
30
-
36
extension configurations. In other words, in addition to determining the maximum allowable moment with all of the outriggers
30
-
36
fully extended, the maximum allowable moment for different combinations of various extensions for each of the outriggers
30
-
36
is preferably elevated (i.e., such as when the first outrigger
30
is two-thirds extended while the remaining outriggers
32
-
36
are fully extended; or when the first outrigger is one-third extended while the remaining outriggers
32
-
36
are fully extended; etc.). In the preferred embodiment with four outriggers
30
-
36
, there are 256 different position combinations of outrigger
30
-
36
extension configurations. To simplify the number of calculations even further, the maximum allowable moment values could be calculated for the outriggers
30
-
36
in only either unextended or fully extended positions.
Alternatively, instead of entering predetermined maximum allowable moment values, the input device
104
can be used to input the formula necessary to calculate the maximum allowable moment values into the computer
102
. With those formulas entered, the computer
102
then performs the requisite calculations to ascertain the maximum allowable moments for various outrigger
30
-
36
extensions.
The predetermined maximum moment values described above may be supplied to the computer
102
through the input device
104
, or may be preprogrammed in the memory of the computer
102
. The computer
102
, which receives signals from the load sensor
40
, the boom position sensor
42
and the outrigger extension sensors
44
, constantly monitors the load on the leading end
46
of the articulated boom
12
and its position. During the operation, the actual moment created by the articulated boom
12
is a function of the load on the leading end
46
, the position of the leading end
46
with respect to the truck
14
and the weight and positions of the boom sections
18
-
22
. Because the weights of the boom sections
18
-
22
are known, the sensed load and position of the leading end
46
supply all the information necessary to calculate the actual moment created by the articulated boom
12
.
To simplify the requisite actual moment calculation, the positions of the various boom sections
18
-
22
can be assumed generally as a function of the position of the leading end
46
, rather than having to be precisely measured. With this assumption, the actual moment calculation is as follows: The overall weight of the articulated boom
12
is known. The load on the leading end
46
is sensed and recorded. The position of the leading end
46
with respect to the turret
16
and therefore the distance between the leading end
46
and the turret
16
, is sensed and recorded. Based upon trigonometric relationships, the center of gravity of the articulated boom
12
is assumed to be located halfway along the distance between the leading end
46
and the turret
16
. Thus, the actual moment created by the articulated boom sections
18
-
22
is the overall weight multiplied by the distance the assumed center of gravity is from the turret
16
(in this case, one-half of the sensed distance between the leading end
46
and the turret
16
). Similarly, the moment created by the load is the weight multiplied by the distance between the leading end
46
and the turret
16
. Therefore, the actual moment created on the turret
16
, and thus the truck
14
, is calculated by adding the moment created by the weight of the boom sections
18
-
22
to the moment created by the load.
To monitor stability of the articulated boom assembly
10
, the computer
102
, based upon the sensed load on the leading end
46
and the position of the leading end
46
, calculates the actual moment generated by the articulated boom
12
as described above. The extensions of the outriggers
30
-
36
are sensed and stored by the computer
102
. The computer
102
recalls from its memory the maximum allowable moment for the current position of the leading end
46
, which in the preferred is a function of the rotational position of the turret
16
, and the outrigger
30
-
36
extensions. The computer
102
then compares the maximum allowable moment with the calculated actual moment created by the articulated boom
12
. If the actual moment is within a certain percentage of the maximum allowable moment, 10 percent for example the computer
102
sends a warning signal to the output device
106
. The warning signal alerts the operator that the articulated boom system
10
is entering into an unstable condition which could result in tipping if the present course is continued. Alternatively, when the actual moment is approaching a tipping situation (ie. nearing the maximum allowable moment), the computer
102
signals the output device
106
to shut down operation of the articulated boom system
10
.
C. Articulated Boom System
210
An alternative embodiment of an articulated boom system
210
having a monitoring system in accordance with the present invention is shown in FIG.
3
. The articulated boom system
210
includes an articulated boom
212
and a truck
214
. The articulated boom assembly
212
includes a turret
216
, a first boom section
218
, a second boom section
220
, a third boom section
222
, a first actuator assembly
224
, a second actuator assembly
226
and a third actuator assembly
228
. The truck
214
acts as a base and includes driven outriggers or support legs
230
,
232
,
234
and
236
which are used to stabilize the articulated boom system
210
against the weight of the articulated boom
212
and any load carried by the articulated boom
212
, such as a hose
238
shown in FIG.
3
. In addition to these standard components, the articulated boom system
210
includes a monitoring system, some components of which are shown in FIG.
3
.
The monitoring system includes a load sensor
240
, a first actuator sensor
242
a second actuator sensor
244
, a third actuator sensor
246
, a rotational sensor
248
and outrigger extension sensors
250
. The load sensor
240
is located on a leading end
252
of the articulated boom
212
. The first actuator sensor
242
is located on the first actuator assembly
224
. The second actuator sensor
244
is located on the second actuator assembly
226
. The third actuator sensor
246
is located on the third actuator assembly
228
. The rotational sensor
248
is located on the turret
216
. Finally each of the outriggers
230
-
236
has one outrigger extension sensor
250
.
The articulated boom system
210
is constructed and operates in a manner similar to that described and shown in FIG.
1
. However, the boom position sensor
42
(shown in
FIG. 1
) is now comprised of the first actuator sensor
242
, the second actuator sensor
244
, the third actuator sensor
246
and the rotational sensor
248
. Each of the actuator sensors
242
-
246
sense a parameter related to operation of a corresponding one of the actuator assemblies
224
-
228
, which is indicative of a total load supported by each of the actuator assemblies
224
-
228
. The total load supported by each of the actuator assemblies
224
-
228
can be described in terms of the forces applied by the actuator assemblies
224
-
228
on the corresponding boom sections
218
-
222
.
Specifically, the first actuator sensor
242
senses a parameter which is indicative of a total load supported by the first actuator assembly
224
. The second actuator sensor
244
senses a parameter which is indicative of a total load supported by the second actuator assembly
246
. The third actuator sensor
248
senses a parameter which is indicative of a total load supported by the third actuator assembly
228
. The total load supported by each of the actuator assemblies
224
-
228
includes a load component caused by the weight of the boom sections
218
-
222
themselves as well as a load component caused by the weight of any external load supported by the articulated boom
212
, such as the hose
238
. Additionally, the total load supported by any one actuator assembly is dependent upon the positions of the boom sections
218
-
222
relative to one another and upon the position and distribution of the external load supported by the articulated boom
212
.
In the alternative embodiment illustrated in
FIG. 3
, the actuator assemblies
224
-
228
are hydraulic pistons-cylinder assemblies. Preferably then, the actuator sensors
242
-
246
are pressure sensors which sense the hydraulic pressure in the hydraulic cylinders of each of the actuator assemblies
224
-
228
. The pressure in a particular hydraulic cylinder is indicative of a total load supported by the corresponding actuator assembly
224
-
228
and of the forces experienced by the corresponding boom section
218
-
222
.
To determine the position of the leading end
252
of the third boom section
222
, the extensions of each actuator assembly
224
-
228
is sensed. Further, the rotational position of the turret
216
with respect to the truck
214
is similarly sensed by the rotational sensor
248
. This data, in conjunction with the known lengths of each of the boom sections
218
-
222
provides the position of the leading end
252
with respect to the truck
214
.
Alternatively, sensors
242
,
244
and
246
provide sensor outputs representing the angles between the boom sections. The sensors
242
,
244
and
246
may measure, for example, the linear displacement of the piston rod of each actuator, or the angle(s) between the boom sections, or the angle(s) between the actuator and the boom sections.
The load sensor
240
is preferably used to sense the load on the leading end
252
of the articulated boom
212
, the value of which is used in the actual moment calculation. However, the above-described sensed positions of each of the boom sections
218
-
222
, the position of the turret
216
, the known lengths and weight of the boom sections
218
-
222
can alternatively be used. In other words, by sensing the rotational position of the turret
216
, the angular positions of each of the boom sections
218
-
222
, the known weights and lengths of the boom sections
218
-
222
, the location of the leading end of boom
212
and the center of gravity of boom
212
can be calculated and used to determine the actual moment created by the articulated boom
212
and the load.
Each of the outriggers
230
-
236
has an outrigger extension (or position) sensor
250
. The outrigger extension sensors
250
sense a parameter related to the actual extension (position) of each of the outriggers
230
-
236
. As previously described, where the outriggers
230
-
236
are hydraulically controlled, the outrigger extension sensors
250
are preferably sensors which sense hydraulic pressure in the hydraulic cylinder in each of the outriggers
230
-
236
. The pressure in a particular outrigger hydraulic cylinder is indicative of the total extension of that outrigger
230
-
236
. Alternative, angle sensors (for pivotable, but triggers) or linear displacement sensors (for telescoping outriggers) can function as sensors
250
.
D. Monitoring System
300
FIG. 4
shows an alternative embodiment of a monitoring system
300
for monitoring the operation of the alternative articulated boom assembly system
210
shown in FIG.
3
. The monitoring system
300
includes the load sensor
240
, the actuator sensors
242
-
246
, the rotational sensor
248
, the outrigger extension sensors
250
, a computer
302
, an input device
304
and an output device
306
. The load sensor
240
, the actuator sensors
242
-
246
, the rotational sensor
248
, the outrigger extension sensor
250
, the input device
304
and the output device
306
are all connected to the computer
302
. The computer
302
, the input device
304
and the output device
306
are, in preferred embodiments, substantially the same as described in the monitoring system
100
shown in FIG.
2
.
As previously described, the load sensor
240
senses a parameter indicative of the total load or force acting on the leading end
252
of the articulated boom
212
(shown in FIG.
3
). The actuator sensors
242
-
246
sense a parameter indicative of the extension, and therefore position, of the boom sections
218
-
222
(shown in FIG.
3
). The rotational sensor
248
senses a parameter indicative of the position of the turret
216
(shown in FIG.
3
). The outrigger extension sensors
250
sense parameters indicative of the extension (position) of each of the outriggers
230
-
236
(shown in FIG.
3
). All of the sensors
240
-
250
provide signals to the computer
302
where they are stored.
One or more predetermined values are stored in the memory of the computer
302
. For example, the length of each of the boom sections
218
-
222
is stored. An equation is also stored in the memory of the computer
302
which, when provided with the angular positions of the boom sections
218
-
222
as determined by sensors
242
-
246
and the rotational sensor
248
, calculates trigonometrically the position of the leading end
252
with respect to the truck
214
.
The monitoring system
300
also has one or more predetermined maximum allowable moment values stored in the memory of the computer
302
. This predetermined data is related to the operating parameters of the articulated boom system
210
. More particularly, the predetermined data details the maximum allowable moment that can be imparted by the articulated boom
212
on the truck
214
without causing the truck
214
to tip. In a preferred embodiment, the predetermined allowable moment force or tipping data is based upon various outrigger
230
-
236
extension positions.
During use, the computer
302
constantly monitors, via the sensors
242
-
246
and the rotational sensor
248
, the position of the leading end
252
of the articulated boom
212
. Further, the computer
302
constantly monitors the outrigger
230
-
236
extensions. Whenever the leading end
252
is maneuvered, the computer
302
compares the moment force created by the articulated boom
212
for any new position of the leading end
252
with the predetermined tipping data, which as previously described, is dependent upon the extension, if any, of the outriggers
230
-
236
. When movement of the articulated boom
212
nears a possible tipping situation, the computer
302
sends a warning signal to the output device
306
. In a preferred embodiment, the output device
306
then provides an audible or visual warning to an operator. Alternatively, the output device
306
stops the articulated boom
212
from moving into a potentially tipping situation.
E. Conclusion
The present invention provides a new monitoring system which prevents an articulated boom system from moving into a tipping situation. By sensing the position of the leading end of the articulated boom, the actual moment force generated by the articulated boom, the position of any outriggers, and comparing the actual moment to a maximum allowable moment, the monitoring system constantly monitors the stability of the articulated boom system. Further, by using a GPS sensor (or sensors) to ascertain the position of the leading end, the present invention has many other applications. For example, the computer can be programmed with information regarding the actual work site. Where, for example, obstacles such as power lines, trees, etc., might be encountered, the computer can prevent the articulated boom from moving into possible contact with these obstacles. Normally, the location of various obstacles present at a particular site can easily be determined. The location data for each obstacle is entered into the computer. During operation, the computer, via the GPS sensor, constantly compares the position of the articulated boom with the location of all obstacles. Whenever the articulated boom moves too close to an obstacle, for example within three feet, a warning is provided to the operator. Alternatively, the computer will simply prevent the articulated boom from maneuvering within a few feet of any obstacle. Further, GPS sensor data allows operators to ensure precise placement of the leading end of the articulated boom at desired locations.
An additional application is with concrete slab pouring. An articulated boom system is often utilized with the pouring of large concrete slabs in which a continuous supply of concrete is provided by a hose attached to the articulated boom. The concrete supplied by the house must be as uniform as possible so that the resulting slab is flat. This is sometimes difficult due to movement of the boom, and therefore hose, when the supply of concrete begins to slow or when the contours of the area in which the slab is being formed requires the articulated boom to maneuver through various configurations. In any case, the tip of the hose must be maintained at a relatively constant height with respect to the slab to be formed. This constant positioning can be achieved by the monitoring system of the present invention. The monitoring system determines, via the GPS Sensor or other sensor, the height of the hose tip with respect to the slab. This is done by entering the height of the slab with respect to the base of the articulated boom into the computer and comparing that level with the sensed height of the leading end of the articulated boom (and thus the height of the hose tip). Optimally, the leading end of the articulated boom should be maintained within a range of 9 inches to 3 feet above the floor upon which the slab is being made. If the leading end moves out of range, corrective actions will be taken or the system will be shut down.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, while a GPS sensor or angle sensors have been described as being used to determine the position of the leading end of the articulated boom, other approaches are equally as acceptable. For example, an electrical wire can be run along the length of the entire articulated boom. The electrical field generated by this wire can be sensed and used to ascertain the position of the leading end with respect to the truck. Alternatively, where the articulated boom is used to direct a hose for pumping applications, such as concrete, magnetic dust can be inserted into the material being pumped. This dust will generate a magnetic field resulting in a “picture” or “trace” of the boom sections which are then sensed and used to determine the position of the leading end.
In yet another embodiment, the boom position sensor can be a laser distance meter. With this configuration, a laser transmitter is positioned on the leading end of the articulated boom and a receiver is positioned on the turret. The transmitter sends out a signal which is received by the receiver. This signal, in conjunction with the rotational position of the turret, is indicative of the position of the leading end of the articulated boom with respect to the truck
The preferred embodiments have also been described as utilizing predetermined tipping data for various outrigger extension positions. This can be done for any number of outriggers, and any number of outrigger positions. In other words, the computer can accurately calculate the stabilizing force generated by the outriggers at virtually any outrigger position.
It should also be recognized that several assumptions regarding operation of an articulated boom system can be made which further simplify the various monitoring calculations. For example, because most pumping situations involve approximately the same load on the leading end, this load value can be assumed and used as a constant in the actual moment calculation, thus eliminating the need for the load sensor. Similarly, while the optimum method for determining the actual moment created by the articulated boom includes the weight and position of each of the boom sections, they need not be precisely measured. In other words, the actual moment calculation can assume that the position of each of the boom sections is constant, or is a simple function of the position of the leading end. This constant value is then used in the actual moment calculation. Notably, these assumptions can be made where the specific application is unconcerned with precise moment calculation. When used to obviate potential tipping situations, a precise measurement is unnecessary so long as any assumptions in the various calculations err on the side of safety.
Claims
- 1. A monitoring system for monitoring stability of an articulated boom and pipeline concrete placing system, the articulated boom and pipeline system including an articulated boom for supporting the pipeline having a bottom end rotatably connected to a base and a leading end which is maneuverable with respect to the bottom end, the base further including at least one extendable outrigger, the monitoring system comprising:a boom position sensor, including a global positioning system (GPS) receiver mounted at the leading end of the boom, for providing boom position information from which a horizontal and vertical location of the leading end of the articulated boom can be determined; an outrigger sensor for sensing a position of the outrigger with respect to the base, wherein the outrigger sensor supplies an outrigger signal representative of the sensed outrigger position; and a controller for receiving the boom position information and the outrigger signal, and for determining stability of the articulated boom assembly based upon the boom position information, the outrigger signal, a known weight of the articulated boom and pipeline, a known weight of the pipeline, and a known weight of a material contained in the pipeline.
- 2. The monitoring system of claim 1 and further composing:a load sensor a load on the leading end of the articulated boom, wherein the load sensor supplies a signal to the controller representative of the sensed load.
- 3. The monitoring system of claim 1, wherein the controller determines an actual moment created by the articulated boom on the base.
- 4. The monitoring system of claim 3 wherein the controller compares the actual moment created by the articulated boom to a maximum allowable moment.
- 5. The monitoring system of claim 1, and further comprising:an output device connected to the controller for generating a warning signal in response to the controller.
- 6. The monitoring system of claim 5, wherein the warning signal is generated when a moment created by the articulated boom assembly reaches a predetermined level.
- 7. The monitoring device of claim 1, and further comprising:an input device connected to the controller for entering information related to a maximum allowable moment on the articulated boom system.
- 8. A method for monitoring stability of an articulated boom and pipeline concrete dispensing system, the articulated boom and pipeline system including an articulated boom for supporting the pipeline having a plurality of boom sections, the boom having a bottom end rotatably connected to a base and a leading end which is maneuverable with respect to the bottom end, the base further including an outrigger, the method including:determining a horizontal and vertical position of the leading end of an outermost boom section of the articulated boom with respect to the base by processing information from a global positioning system (GPS) receiver positioned on the leading end; determining a position of the outrigger with respect to the base; and determining stability of the articulated boom assembly and pipeline based upon the sensed position of the leading end and the sensed position of the outrigger.
- 9. The method for monitoring stability of claim 8, further including:determining a load on the leading end of the articulated boom.
- 10. The method for monitoring stability of claim 9, wherein determining stability includes:determining an actual moment created by the articulated boom; and comparing the actual moment to a maximum allowable moment.
- 11. The method for monitoring stability of claim 10, wherein determining an actual moment of the articulated boom is a function of the load and the position of the leading end.
- 12. The method for monitoring stability of claim 10, and further including:receiving information related to a maximum allowable moment.
- 13. The method for monitoring stability of claim 12, and further including:determining a maximum allowable moment based upon the received information, the position of the leading end and the position of the outrigger.
- 14. The method for monitoring stability of claim 8, wherein determining stability includes:determining an actual moment created by the articulated boom as a function of the position of the leading end; and comparing the actual moment to the maximum allowable moment.
- 15. The method for monitoring stability of claim 8, further including:delivering a warning signal based upon the determined stability.
- 16. A method of controlling an articulated boom and pipeline concrete conveying system at a work site, the articulated boom and pipeline system including an articulated boom for supporting the pipeline having a plurality of boom sections movably coupled by a plurality of actuators, the boom having a bottom end rotatably connected to a base and a leading end which is maneuverable with respect to the bottom end, the method including:storing obstacle location data related to location of an obstacle at the work site; determining a horizontal and vertical position of the leading end of the articulated boom by processing information from a global positioning system (GPS) receiver positioned on the leading end; and controlling movement of the articulated boom as a function of the sensed horizontal and vertical position of the leading end and the stored obstacle location data to prevent a collision between the articulated boom and the obstacle.
- 17. The method for controlling of claim 16, wherein controlling the position of the articulated boom includes:comparing the sensed horizontal and vertical position of the leading end with the obstacle location data of the obstacle at the work site; and stopping movement of the articulated boom when the sensed position of the leading end is within a predetermined distance of the location of the obstacle indicated by the obstacle location data.
- 18. A method of controlling an articulated boom system delivering concrete to a floor for forming a slab, the articulated boom system having a boom with a bottom end rotatably connected to a base and a leading end which is maneuverable with respect to the bottom end, and a delivery hose connected to the boom for delivering concrete from a supply source, the delivery hose including a tip located at the leading end of the boom, the method including:storing elevation data related to elevation of the floor; sensing a height of the leading end by processing information from a global positioning system (GPS) receiver positioned on the leading end; and controlling a position of the boom as a function of the sensed height of the leading end and the stored elevation data.
- 19. The method of controlling of claim 18, wherein controlling the position of the boom includes:comparing the sensed height of the leading end with the stored location of the floor, and repositioning movement of the boom with respect to the floor when the sensed height of the leading end is outside of a predetermined distance from the floor.
- 20. The method of controlling of claim 19, wherein the predetermined distance is a range of 9 inches to 3 feet.
US Referenced Citations (26)