EP1849931A2

EP1849931A2 - Improved system for the surveillance and monitoring of the operation of self-propelled, articulated-boom machines, such as concrete pumps

Info

Publication number: EP1849931A2
Application number: EP06123187A
Authority: EP
Inventors: Davide Cipolla; Nicola Pirri
Original assignee: COMPAGNIA ITALIANA FORME ACCIAIO S P A
Current assignee: COMPAGNIA ITALIANA FORME ACCIAIO S P A
Priority date: 2006-04-24
Filing date: 2006-10-30
Publication date: 2007-10-31
Anticipated expiration: 2026-10-30
Also published as: EP1849931A3; ITMI20060818A1; EP1849931B1

Abstract

System for the control and monitoring of the operation of self-propelled, articulated-boom machines, in particular concrete pumps, comprising a plurality of sensors capable of continuously detecting instant data concerning the geometric conditions of the operating attitude of the machine and the load conditions thereof, as well as a central processing unit which, on the basis of such data and of previously-stored safety parameters, continuously checks for the meeting of one or more critical conditions for machine safety, such as levelling, overturning moment, stability, resonance swinging of the articulated boom.

During machine operation, when at least one of said critical conditions is approached beyond a threshold value, the central unit provides to actuate a sound and visual alarm signal and at the same time to activate automatic cycles for the gradual stop of the machine and/or for gradually moving away from said critical condition.

Description

The present invention concerns a system for controlling and monitoring the operation of self-propelled, articulated-boom machines, in particular concrete pumps.
The problems deriving from the use of these large machines are known, the critical point whereof, regarding the masses involved and with the high working stresses, leads designers to invest significant funds in the attempt to make the operation of such machines increasingly easier and to minimise the risk of injury.
In order to achieve equilibrium and stable conditions of the self-propelled vehicle, also called carriage, whereon the equipment of the concrete pump and of the corresponding articulated boom for delivery is installed, the use of lateral stabilisers is well-known. The stabilisers are typically shaped as extendable legs resting on a point removed from the centre of equilibrium of the carriage, thereby extending the support base. This arrangement is especially useful in conditions of rough terrain, as is often the case on the building sites where such machines operate.
However, the use of this kind of machine requires the knowledge of very specific techniques by the operator, which he has to follow carefully, especially during the extension and use of the delivery boom, on penalty of the risk of machine overturning or exceeding the maximum stress values provided.
As a matter of fact, although this type of machine is designed according to high standards of safety, improper use of the same may lead to early or unexpected structure failures. The particular structure of the articulated boom, and pressing market demand for ever longer booms, make these events a likely occurrence.
It is also known that, whenever the boom is fully extended and the concrete pump is in a steady state, resonance phenomena may occur causing the boom to swing with progressively increasing width. In the absence of an immediate action by the operator to vary the pump speed, this phenomenon may quickly lead to the breakage or deformation of the boom and of the support thereof; however, even in the presence of such action, since the operator is capable of detecting the onset of the phenomenon only with a certain delay over its beginning, a remarkable increase of machine wear is nevertheless produced as well as an increment of the risks of breakage. It must furthermore be noted that - also due to the fact that the majority of these vehicles is supplied to building companies through a hiring contract - the operators often do not pay special attention to operation abnormalities and to the ordinary maintenance operations to be carried out. This obviously implies greater machine wear and consequently increased risks of breakage due to distraction or improper use of the machine. The need for machines of this type provided with automatic monitoring devices is hence ever increasing, both so as to prevent improper or dangerous use, and to encourage the regular carrying out of ordinary and special maintenance actions on said machines.
As a matter of fact, the desired safety aims cannot be achieved simply by acting on the sturdiness of the machine structures or increasing the respective safety coefficients in the design thereof. As a matter of fact, given the growing demand therefor by users of long-boom machines, this would lead to a considerable increase of the weight and overall size of the machine. However, this consequence is not acceptable both due to the growing difficulties in the type-approval procedure for such machines by the relevant authorities, and because the industry market, on the contrary, has a keen interest in light-weight, compact and inexpensive machines.
Thus, the Applicant had long set itself the problem of supplying lorry-mounted, articulated-boom pumps and similar machines provided with safety devices capable of allowing correct use of the vehicle, and which were at the same time as light-weight as possible and suitable to the actual requirements of use of the specific client.
As a matter of fact, in patent EP 1356910 , the Applicant claims a system for the monitoring and control of the operation of articulated-boom machines, which system employs a plurality of sensors for detecting the data concerning position, attitude and operation parameters of the individual operation elements of the machine. The sensors transmit the detected data to a central unit, which processes them and compares them with reference data relating to the correct use of the machine, and said unit reports to the operator the result of the analysis, visualising information and/or alarm signals on a suitable display.
However, the invention according to the above-said patent, despite bringing a relevant contribution towards a more controlled use of machinery in the sector, is unable to meet the increasing demand for improved active safety appealing to the market today. At the same time, for safety reasons this invention does not provide the opportunity to fully exploit the entire potential of the machines even near the threshold safety conditions, without the machine or operator being exposed to risky conditions caused by possible human mistakes in the conduction of the machine and/or in the interpretation of the information supplied by the system. In particular, the need to lift the operators from the direct responsibilities of static/dynamic running of the machines, thereby enabling them to concentrate more on the technical completion of the process only is increasingly felt.
The aim of the present invention is hence to provide a control and monitoring system which is capable of continuously supervising the machine during the operation thereof, thereby minimising the responsibilities of the operator in charge thereof.
A further object of the present invention is to supply a self-propelled, articulated-boom machine for concrete distribution in casting areas, which comprises automatic monitoring systems capable of reducing the risk of breakage or abnormal wear phenomena of the machine, in particular of the articulated boom thereof.
Still another object of the invention is to provide a self-propelled, articulated-boom machine wherein said monitoring system is capable of continuously informing the operator about the operating and static/dynamic equilibrium conditions of the machine and furthermore wherein said monitoring system is capable of signalling any irregularity of use and of correcting any incorrect setting or control by the operator in the conduction of the machine.
The above objects are achieved, according to the present invention, through a control and monitoring system having the features defined in claim 1. The dependent claims concern other particularly preferred features of the invention.
Further details, features and advantages of the system according to the invention will in any case be more evident from the following description of a preferred embodiment of the same, given by way of example and shown in the attached drawings, wherein:

fig. 1 is a side elevation view of a lorry-mounted concrete pump; and
fig. 2 is a top plan view of the pump of fig. 1.

Fig. 1 shows, by way of example of an articulated-boom machine addressed by the present invention, a lorry-mounted concrete pump, wherein the control and monitoring system of the invention is embedded.
In the drawings, F marks the concrete pumping assembly, which receives the concrete from a loading hopper T and sends it pressurised to a delivery pipe P. Pipe P is an articulated pipe which runs along articulated boom B to an end hose M for concrete delivery to the casting areas. The articulated boom shown in fig. 1 consists of five blocks B1-B5, the last block B5 preferably having an intermediate joint H to allow greater manoeuvrability of the end part of boom B in the casting area. The control and monitoring system of the invention, anyhow, is applicable to lorry-mounted pumps of any known type, regardless of the number of blocks (normally from 3 to 6) making up the articulated boom thereof.
In order to ensure stability of the lorry-mounted pump in a wider area than the one limited by the perimeter of carriage V, extendable stabiliser legs G are provided, capable of transferring the resting points on the ground to a certain distance from the carriage. Legs G may be differently shaped, according to the use for which the lorry-mounted pump is intended, without the function thereof varying from a conceptual point of view. In the embodiment shown, front legs G are of the fixed, slip-off type, while the rear legs are of the jib-like swivelling type. The structure and functions of all the elements detailed above are well-known to a person skilled in the field and will therefore not be described in further detail in the following.
According to the main concept of the present invention, the lorry-mounted pump is further provided with a plurality of sensors for real time detection of instant data concerning the geometrical conditions of the operating attitude of the different machine components and the load conditions of the same, as well as the operation data of pump assembly F. The data detected by said sensors are then collected in a central processing unit which provides to acquire the signals, to possibly codify them and extract therefrom numeric values which are meaningful for the operator. Said central unit is finally connected, through an interface can-bus, to a display, preferably employing a graphic interface, whereon the operator is capable of reading the instant values representing the operation conditions and the further indications about the safety conditions of the machine, as better detailed in the following.
As a matter of fact, on the one hand and according to the prior art mentioned above, the information displayed on the display consists of intelligible indications useful to the operator, on the basis whereof he may act independently to guide the machine and perform the correction operations which may be suggested by the system, for example by moving the articulated boom to return to an operation area, or by folding the boom to return to safer conditions, or again by changing the pump operation speed to avoid resonance phenomena. According to this first function, the operator hence manually drives the machine not only on the basis of his personal practical experience, but also on the basis of specific information on the instant conditions of the machine attitude and loads.
On the other hand, according to the novel concept of the present invention, such data are instead further processed by the central unit to continuously verify the compliance of one or more conditions which are critical for the safety of the lorry-mounted pump, the parameters or the logical functions of said conditions being preset in the memory unit of the machine central unit.
Whenever, during machine operation, at least one of said critical conditions is approached exceeding a preset threshold value, for example 90% of the threshold value, the central unit provides to actuate a sound and visual alarm signal and to simultaneously actuate suitable automatic cycles for the gradual stopping of the machine and/or for the gradual distancing from said critical condition.
As a matter of fact, according to a particular aspect of the present invention, the critical condition is detected with a sufficient advance over the safety thresholds, so as to allow a gradual system action on the moving parts, which are hence stopped or deviated according to suitable deceleration ramps. It is thereby possible to avoid the onset of dynamic phenomena resulting from the sudden stop of said machine parts, which phenomena may often be the root cause of a dangerous overstepping of machine components, or of the machine itself, of critical conditions.
In particular, the critical conditions which may preferably be monitored in a lorry-mounted concrete pump according to the preferred embodiment of the present invention, are the following:

1) contact with the ground and levelling of the carriage;
2) overturning moment applied to the carriage by the articulated boom;
3) static stability of the carriage;
4) resonance swinging in the boom during concrete pumping.

The above critical conditions are detected by a suitable network of sensors arranged in a suitable position on the machine, the signals coming from said detection sensors being acquired by the central unit and suitably processed by the same, on the basis of the geometric parameters of the machine, so as to obtain processed data concerning the forces and the moments instantaneously acting on the machine. Such processed data are then compared with the parameters concerning the safety thresholds, previously stored in a memory area of said central unit, thereby allowing to establish at any time the condition of closer or farther approaching of said critical conditions.
In particular, for the different critical conditions reported above, the following sets of sensors are provided:

Condition A - contact with the ground and levelling

As far as checking correct contact with the ground is concerned, load sensors are provided on the support feet of stabiliser legs G, i.e. flexure sensors detecting flexure of the legs following the lifting of carriage V on the same, i.e., again, pressure sensors in the cylinder-piston assemblies actuating stabiliser legs G.
As regards carriage levelling, two level sensors are instead provided, according to the main longitudinal and transversal axes (X and Y) of carriage V.

Condition B - overturning moment

The value of the overturning moment applied to carriage V by articulated boom B is calculated by an angle sensor of the first element B1 of the articulated boom to the horizontal plane and a pressure transducer detecting the pressure of the work fluid in the cylinder-piston assembly which actuates the lifting of boom B1.

Condition C - stability

The calculation of the overall stability of carriage G must take into account the instantaneous overturning moment (condition B) mentioned in the preceding point, the angular position of boom B, the carriage levelling (condition A) and, finally, the arrangement of support legs G. In addition to the data detected for the preceding conditions A and B, a slip-off sensor must hence be provided for each of front legs G, as well as an angular opening sensor of rear legs G, and an angular position sensor of the fifth wheel whereon turret S supporting boom B rests.

Condition D - boom swinging due to resonance

This condition is detected by measuring the variation over time of the angular position of boom B or of one of the elements thereof, and of the pressure in the cylinder-piston assembly controlling the first block of boom B. The onset of the swinging condition and the greater or smaller swinging width of the individual elements of boom B depend on the mutual angular position of such elements, as well as, of course, on the speed of the pumping assembly F. An overall detection of this phenomenon is hence possible from the sole angular position sensor of boom B1, or through a series of similar sensors also detecting the angular position of the other booms B2-B4, or by controlling the development of the pressures within the cylinder-piston assemblies controlling the various joints of boom B. In this last case, the start of the swinging movement is always detected promptly, regardless of the individual boom element where such phenomenon begins.
On the basis of all the information collected by the sensors described above and of the preset safety parameters or functions, the central unit of the control and monitoring system according to the present invention is therefore capable of determining the admissible operation range of the lorry-mounted pump and in particular of the articulated boom of the same, independently for each of the critical conditions detected above. As a matter of fact, for each of such conditions it is always possible to set threshold parameters or a threshold function as well as a maximum approaching percentage to such threshold, beyond which the control system actuates the alarm signals and begins the automatic manoeuvre for moving away from the critical condition, for example by changing the frequency of the externally applied force i.e. the number of pumping cycles per minute.
Unlike the systems of the prior art, the control and monitoring system of the present invention hence does not limit itself to simply pointing out to the operator admissible and non admissible work areas, leaving to the operator the full responsibility of managing the machine in the frame of such indications, but provides itself to monitor the different possible critical conditions found during use of the machine and to monitor the various moving components of the machine, so as to avoid that said critical conditions are undesirably approached.
This approach evidently allows a much more flexible and wide use of the machine. As a matter of fact, for obvious reasons, in the conventional approach wide safety margins had to be provided when pinpointing the admissible work areas, precisely to take into account possible human errors when manoeuvring the machine, hence excluding large, even only potentially dangerous work areas. The system of the present invention is instead capable of excluding very precisely the areas where it is actually dangerous to operate, thereby reducing the risks for the machine and for the operator, and at the same time remarkably widening the machine operation field.
Of course the nature of the actions of the control and monitoring system of the present invention differs remarkably depending on the monitored critical condition and such actions may or may not imply merely a slowing down or instead require work interruption. In particular, it is necessary to take into account that the system is programmed so as to always accept any manual correction setting by the operator - for example even in the choice of a specific way out from a critical condition which has become excessively close - provided, however, that the choice of the operator actually implies in this last case a distancing and not instead - due to human error - getting even closer to said condition.
Among the various critical conditions detailed above, conditions A and B are considered by the system as basic preconditions, the meeting whereof is necessary to give consent to machine operation. As a result, should these critical conditions, during the subsequent completion of the process, be accidentally approached exceeding a preset threshold value, for example 90% of the maximum admissible value, the system would provide to immediately inhibit the further completion of the process until the above-said conditions are newly met. A condition of this type may occur for example following ground sagging under the support feet of stabiliser legs G, or due to improper use of boom B for the handling of loads, or due to the configuration of a smaller stabilisation area than the one provided in the plan.
Meeting conditions C and D is instead carried out by the system by monitoring the boom position and the operation speed of pump assembly F. Thus, if the unit detects that the machine has exceeded the threshold value provided for the stability thresholds, it provides to change the position of boom B - for example by stopping the rotation or the extending motion thereof, or by bringing it back in the position immediately preceding the exceeding of the threshold - so as to bring the machine back into a condition of greater safety. In this way out from the critical condition, the system accepts, as was said before, the correction actions manually set by the operator, however, only if such actions act indeed in the direction opposite to the critical condition, and this is so until the machine has fully returned within the above-said threshold value.
The system behaves similarly - i.e. with an action not interrupting the process - also in connection with swinging condition D. As a matter of fact, in this case the central unit monitors the swinging movements of the articulated boom or of the different elements thereof, during concrete distribution operations. Should these swinging movements approach the frequency of pumping assembly F, the central unit provides to vary for the time required the working frequency, and hence concrete flow rate, thereby avoiding resonance phenomena. However, the system is capable of detecting the onset of the swinging phenomenon well in advance of when the phenomenon may be perceived by the operator and the action on the pump frequency may hence be much prompter, thereby avoiding at the root the start of abnormal stresses in articulated boom B and in the support structures of the same. It is hence, to all effects, an active-type dampening system of the swinging movements in the boom.
The monitoring action, by the central unit, of the various moving components of the machine is performed in a manner very well-known per se, by using fluidodynamic circuits and electrovalves which are suitably arranged along the same circuits. As already said above, a feature of the system of the present invention is that, whenever the threshold value of a critical condition is exceeded, it brings the moving components of the carriage in a safe position in a smooth and gradual way, i.e. by providing ramps which slow down the current movements. This object is achieved by using proportional valves. Thereby, the risk of sudden - and hence dangerous - adjustment movements of the system, due to an excessively abrupt arrest, is considerably reduced.
The control and monitoring system of the present invention further provides a self-teaching system of the boom movement operations, through calculation logic processes which are well-known per se to people skilled in the field, so it is capable of storing, on demand and with a suitable code, a particular sequence of boom-moving operations performed by the operator. The system is further capable - when it is supplied with the above-said code - of performing the same procedures which were carried out by the operator in due time with the same sequential order. When repeating the sequence, however, the system operates intelligently, a priori avoiding exceeding the threshold of the critical conditions that may have been encountered during the self-teaching step, hence suggesting a correct boom trajectory for the required process.
There are various technical processes to achieve such result, depending mainly on the choice of monitoring electronics and programming languages employed; however, the network of connections and the operational logical sequence employed by the central unit to achieve such result may be clearly understood from the description of this invention.
The data used by the system for supplying indications to the operator and for monitoring the machine are stored in a suitable "data register", i.e. in a memory device of the central unit, capable of also storing use abnormalities, for example through a "threshold exceeded" signal whenever the articulated boom is led into an area which the central unit has deemed impassable or nearly so. The data thus stored are used by the person in charge, or by the owner, of the machine, or otherwise by the body in charge of maintenance, to reconstruct the use that was made of the machine, the duration and number of times that the machine worked in conditions close to or outside the preset threshold values, and, in an integrated manner, is suitable to create a schedule of ordinary maintenance operations.
As a matter of fact, these data, integrated over time, provide useful indications which allow to schedule maintenance actions according to requirements and based on the actual exploitation of machine potential. For example, the central unit, based on preset parameters, may define if the use of the machine integrated over time has led to a condition requiring a maintenance action, correspondingly alerting the operator to signal the maintenance need, which maintenance may appear to be even remarkably earlier or later than what has been provided for average use in the usual maintenance programmes.
A system thus integrated, in addition to promptly providing intelligible data concerning maintenance operations, allows to involve the designers and hence to be of interest to the machine manufacturer: as a matter of fact, the data collected over a long time may be used to create various "profiles" of use, specific for the individual client or for the type of user, and at the same time to plan the correction actions in a designing and manufacturing phase, providing further aids to safety only where really needed, so as to always guarantee the lowest cost compatibly with actual needs.
From the preceding description it should be clear how the control and monitoring system of the present invention - comprising a network of sensors, a central processing unit, proportional actuators of the moving parts of the lorry-mounted pump, and a storage device - has fully achieved all the objects set forth in the preliminary remarks.
In particular, according to the invention, a control and monitoring system is provided, which is capable of detecting the instant operation data of the machine, of checking on the basis of such data the observance of critical operation conditions of the machine and of performing in a prompt and automatic manner the suitable correction manoeuvres for quickly returning to the admissible operation areas. Moreover, through the integration over time of the operation data stored in the unit storage, it is possible to correctly and specifically establish the moment in which to perform maintenance actions for each individual machine; the system further allows to also acquire important information which may be useful for scheduling.
Ultimately, through the control and monitoring system of the present invention, the use of self-propelled, articulated-boom machines is remarkably simplified, thereby making it possible for such equipment to be safely driven even by less skilled operators.
It is understood, however, that the invention is not limited to the particular embodiments illustrated above, which represent only non-limiting examples of the scope of the invention, but that a number of variants are possible, all within the reach of a person skilled in the field, without departing from the scope of the invention as defined in the accompanying claims.

Claims

System for the control and monitoring of the operation of self-propelled, articulated-boom machines, in particular lorry-mounted concrete pumps, of the type comprising a plurality of sensors capable of detecting instant data concerning the geometric attitude of the moving components of the machine and the load and operation data of the same, as well as a central processing unit capable of continuously receiving such data to process them and compare them with previously stored safety parameters, characterised in that said central unit continuously checks for the meeting of one or more critical conditions for machine safety and, when at least one of said critical conditions is approached beyond a predefined threshold value, the central unit actuates an alarm signal and simultaneously activates automatic cycles for stopping the machine and/or moving away from said critical condition.
System as in 1), wherein said critical condition is one or more of: contact with the ground and levelling, overturning moment of the articulated boom, carriage overturning stability, resonance swinging of the articulated boom.
System as in 2), wherein said automatic cycles for stopping and/or removing the machine are performed in a gradual manner, according to ramps for slowing down the moving parts.
System as in 1), wherein said threshold value is set at 90% of the maximum safety threshold of each of said critical conditions.
System as in any one of the preceding claims, wherein said unit is provided with a self-teaching function for storing a sequence of operations manually set by the operator and for repeating it on demand.
System as in 5), wherein during the automatic repetition of a stored sequence, the central unit suggests a path in which it is automatically avoided to exceed the thresholds of said critical conditions which may have been exceeded during the self-teaching step.
System as in any one of the preceding claims, wherein the detected data are stored in a data register and used for scheduling machine maintenance.