Bridge construction global monitoring method and system based on finite element real-time calculationTechnical Field
The invention belongs to the technical field of bridge engineering construction and maintenance monitoring, and particularly relates to a bridge construction global monitoring method and system based on finite element real-time calculation.
Background
In the whole life cycle of the bridge, from construction to operation and subsequent long-term maintenance, ensuring the safe and stable operation of the structure is always a core task, and finite element calculation plays a key role. The traditional finite element computing technology is mainly used for constructing a model according to a design scheme, inputting a design load, and carrying out analysis aiming at key components with stress concentration by means of commercial software such as ANSYS and the like. And then, setting an early warning threshold according to the allowable stress of the key component materials, installing stress sensors on the components, and comparing the values of the sensors with the threshold to realize monitoring early warning in construction and operation stages.
However, with the development of bridge engineering, conventional approaches have revealed a number of limitations. In the construction stage, the commercial software has extremely high calculation professionals and complicated flow. Once the conditions such as design change, process adjustment or sudden weather appear in the construction site, the recalculation is time-consuming and laborious, seriously influences the timeliness of construction monitoring, and is difficult to meet the urgent need of timely feedback of the structural mechanical state in the construction process. Meanwhile, the construction site working condition is complex, and the actual load and the design load are often different, so that originally-recognized key components are not actually key parts, and the real key components are not provided with stress sensors, so that a security supervision leak is formed.
The problem is also pronounced when entering the operational phase. The dynamic changes of traffic flow and vehicle load types and the long-term effects of environmental factors such as temperature, humidity, wind power and the like are different from design expectations. Only by means of the traditional finite element calculation and monitoring mode based on key components, the mechanical state of the whole bridge structure under complex and changeable actual operation conditions is difficult to comprehensively reflect. Because the stress change of each part of the bridge cannot be mastered timely and accurately, the discovery and treatment time for early diseases can be missed, the safety risk of the bridge structure is increased, and the service life is shortened. Moreover, the method cannot comprehensively evaluate the problems of local damage accumulation, structural performance degradation and the like possibly occurring in the long-term use process of the bridge, and is not beneficial to formulating a scientific and reasonable maintenance strategy.
In view of this, it is urgently needed to construct an innovative finite element real-time computing system, which is suitable for the comprehensive application scenario of bridge construction and operation. By constructing the efficient finite element calculation service end, load data of construction and operation sites can be acquired in real time, and the load data can be accurately acquired and used for calculation no matter mechanical equipment load and material stacking load in construction stages, traffic load and environment load in operation stages and the like. The system can monitor the stress state of each part of the bridge in real time, realize the real-time and comprehensive performance of construction monitoring, effectively solve the problem of construction stage, continuously track the structural state of the bridge in the operation stage, timely detect potential safety hazards, provide powerful guarantee for long-term safety operation of the bridge, truly realize global monitoring of the whole life cycle of the bridge, and greatly improve the safety and reliability of the bridge.
Disclosure of Invention
The invention aims to overcome the defects of the existing bridge monitoring technology in the construction, operation and maintenance stages. By constructing the efficient finite element computing server, load data are acquired in real time, real-time monitoring and early warning of the global stress state of the bridge are achieved, computing efficiency is improved, adaptability to complex working conditions is enhanced, and safety and stability of the whole life cycle of the bridge are ensured.
Aiming at the defects or improvement demands of the prior art, the invention provides a bridge construction global monitoring method based on finite element real-time calculation, which comprises the following steps:
s1, constructing a bridge finite element model, encoding each finite element unit, ensuring the uniqueness of the encoding, determining the bridge construction stage according to a construction scheme, endowing each unit with corresponding construction stage attributes according to the construction completion sequence of different parts, storing the constructed finite element model into a database, and distributing a unique bridge identification code;
S2, constructing a three-dimensional space geometric corresponding relation between the finite element model and the BIM model, and mapping the finite element unit and the BIM model component;
s3, determining allowable stress through construction materials of bridge members, and further setting early warning threshold values of each unit of the finite element;
S4, determining a load variable to be considered in the construction process;
s5, configuring a finite element calculation server to perform real-time calculation;
S6, obtaining a finite element calculation result, modifying the stress of each component of the three-dimensional BIM according to the result, and displaying the result globally;
s7, setting a three-level early warning mechanism to perform monitoring early warning.
Further, each finite element unit is encoded in S1, and a globally unique UUID is randomly generated for each unit by using an MD5 algorithm.
Further, the specific method for mapping the finite element unit and the BIM model member in S2 is as follows:
each finite element corresponds to a unique BIM model member, and one BIM model member corresponds to a plurality of finite element elements;
reading BIM model data, starting from a first component, firstly establishing an outsourced sphere, and recording the center coordinate and radius of the sphere;
traversing all finite element units which are not mapped yet, calculating the distance from the finite element units to the center of the sphere, and rapidly screening out the finite element units to be selected by the distance smaller than the radius of the sphere;
performing fine calculation on the to-be-selected finite element unit and the BIM model component, establishing a mapping relation when the BIM model component completely contains the finite element unit, recording the BIM model component code in the finite element unit attribute, and storing the BIM model component code in a database;
All components of the BIM model are cycled through to perform operations until all finite element elements complete the mapping.
Further, the specific method for setting the early warning threshold value of each unit of the finite element in S3 is as follows:
acquiring construction materials of each component of the BIM through design information, and searching allowable stress of the materials;
Searching a finite element unit corresponding to each BIM model component by using the mapping relation, setting allowable stress attribute for the finite element unit, and storing into a corresponding field of a database;
And setting an early warning threshold value for each finite element unit, setting a three-level early warning threshold value for 65% -75% of allowable stress, setting a two-level early warning threshold value for 75% -85% of allowable stress, and setting a first-level early warning threshold value for 85% -95% of allowable stress, and storing the two early warning threshold values into corresponding fields of a database respectively.
Further, the specific process of determining the load variable to be considered in the construction process in S4 is as follows:
Determining environmental load, including temperature, wind speed and wind direction, and respectively distributing unique ID numbers in a monitoring result database;
determining weight load, including the size and position of the weight, and respectively distributing unique ID numbers in a monitoring result database;
configuring a corresponding bridge identification code for each load variable so as to facilitate the calculation and the real-time query acquisition afterwards;
Binding the construction site instrument code with the ID number of the corresponding load variable, and transmitting the acquisition result into a database at regular time by utilizing a network interface.
Further, the load variable obtaining process is as follows:
The method comprises the steps of additionally installing a sensor, a camera and a weighing module on a project site, acquiring real-time load parameters of bridge construction, transmitting the real-time load parameters to a finite element computing server by utilizing wireless communication or Internet of things to perform real-time computation, acquiring environmental load by the sensor installed on the site, identifying the position of a vehicle by the weighing module and combining the camera, and analyzing the size and the position of the weight load.
Further, the specific method for configuring the finite element computing server in S5 to perform real-time computation includes:
starting a new finite element real-time calculation task at the server, and transmitting a corresponding bridge identification code;
The server side imports a finite element model from a database according to the bridge identification code;
determining finite element units to be designed for current calculation through a current bridge construction stage, comparing the construction stage attribute of each unit with the current construction stage, and if the construction stage attribute is temporally behind the current construction stage, not calculating;
reading the latest load data from a database through the bridge identification code, wherein the latest load data comprise temperature, wind speed, wind direction, weight and weight position;
The calculation is carried out at regular time, the timing interval is set between 1 second and 3 seconds, and the real-time performance of the calculation is ensured.
Further, the three-level early warning mechanism in S7 is specifically as follows:
The server calculates and acquires the real-time stress of each finite element unit in real time, and compares the real-time stress with the three-level early warning value of the corresponding unit;
If the early warning is triggered, the early warning information is displayed and sent to the front end, wherein the information content comprises a finite element unit code, a finite element unit coordinate position, a real-time stress value and an early warning grade;
the front end receives the message, and when the message is determined to be early warning, an early warning mark is added at a position corresponding to the three-dimensional model based on the coordinate position;
setting three-level early warning as yellow marks to remind workers of the construction condition;
Setting the secondary early warning as an orange mark to remind workers of carrying out necessary measures, so that risks are reduced;
setting the first-level early warning as a red mark, reminding workers to emergently suspend construction, and eliminating risks.
As a second aspect of the present invention, there is provided a bridge construction global monitoring system based on finite element real-time calculation, comprising:
The finite element model construction unit is used for constructing a bridge finite element model, coding each finite element unit, guaranteeing the uniqueness of the codes, determining the bridge construction stage according to a construction scheme, endowing each unit with corresponding construction stage attributes according to the construction completion sequence of different parts, storing the constructed finite element model into a database, and distributing unique bridge identification codes;
The finite element and BIM model mapping unit is used for constructing a three-dimensional space geometric corresponding relation between the finite element model and the BIM model and mapping the finite element unit and the BIM model component;
The stress early warning threshold unit is used for determining allowable stress through construction materials of bridge members, so that early warning threshold values of each unit of the finite element are further set;
the load variable unit is used for determining load variables to be considered in the construction process;
the real-time computing unit is used for configuring the finite element computing server to perform real-time computation;
The finite element result display unit is used for acquiring finite element calculation results in real time on a front-end webpage, modifying the stress of each component of the three-dimensional BIM model according to the results and displaying the results globally;
and the monitoring and early warning unit is used for setting a three-level early warning mechanism and carrying out monitoring and early warning.
As a third aspect of the present invention, there is also provided a computer-readable storage medium having stored thereon a computer program that is executed by a processor to perform any of the steps of the above-described bridge construction global monitoring method based on finite element real-time computation.
In general, the above technical solutions conceived by the present invention, compared with the prior art, enable the following beneficial effects to be obtained:
1. According to the bridge construction global monitoring method based on finite element real-time calculation, the special finite element calculation server is constructed, the adaptive algorithm core is carefully written, the parallel computing capability of the high-performance GPU is fully exerted, and efficient real-time finite element calculation is realized. The situation that complex business software is relied on in the past is changed, the on-site changeable situation can be rapidly dealt with, the calculation efficiency is greatly improved, the timeliness of construction monitoring is ensured, the structural mechanical state in the construction process can be fed back in time, and a powerful support is provided for construction decision.
2. According to the bridge construction global monitoring method based on finite element real-time calculation, when the bridge finite element model is constructed, unique UUID codes generated based on MD5 algorithm are endowed to each unit. This code becomes a unique identification of the unit in the global, closely linked with each module. In the finite element calculation module, the server can accurately identify each unit, the global unit is efficiently analyzed, the calculation result is ensured to accurately correspond to the actual part, and a reliable data base is provided for global monitoring.
3. According to the bridge construction global monitoring method based on finite element real-time calculation, a calculation result is presented by combining a front-end webgl technology with a three-dimensional BIM model through a monitoring display module. The unique coding of the units ensures that each unit is accurately positioned in the three-dimensional model, and the one-to-one correspondence between the virtual model and the actual bridge structure is realized. In the early warning link, the position of the early warning unit can be quickly locked by means of the codes, the linkage global shows its scope of influence. The constructor can intuitively know the states of all parts of the bridge from the global level, take measures in time, realize global monitoring in all directions without dead angles and powerfully ensure the safety of bridge construction and operation.
Drawings
FIG. 1 is a flow chart of a bridge construction global monitoring method based on finite element real-time calculation in an embodiment of the invention;
FIG. 2 is a general architecture of a global monitoring method for bridge construction based on finite element real-time computation in an embodiment of the present invention;
FIG. 3 is a diagram showing global stress during a main tower construction phase in accordance with an embodiment of the present invention;
FIG. 4 is a diagram showing global stress for a lifting phase 1 according to an embodiment of the present invention;
FIG. 5 is a diagram showing global stress for lifting phase 2 according to an embodiment of the present invention;
FIG. 6 is a diagram showing a global stress for closure in accordance with an embodiment of the present invention;
Fig. 7 is a system unit diagram of an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention. In addition, the technical features of the embodiments of the present invention described below may be combined with each other as long as they do not collide with each other.
Example 1
Referring to fig. 1, embodiment 1 provides a bridge construction global monitoring method based on finite element real-time calculation, which includes:
The embodiment 1 aims at constructing an efficient finite element calculation server, acquiring load data of a bridge construction site in real time for calculation, and monitoring and early warning the real-time stress state of each part of the bridge. The method ensures the real-time performance of construction monitoring through real-time calculation, realizes safe monitoring without omission through monitoring the state of each part of the bridge, and ensures the global performance of monitoring.
Referring to fig. 2, the method is generally divided into three modules:
1. And a finite element calculation module. And on the other hand, the finite element real-time calculation is flexibly invoked through an interface, so that a result is obtained, and the monitoring instantaneity is ensured.
2. And the load monitoring module. And (3) installing a sensor on the project site, acquiring real-time load parameters of bridge construction, and transmitting the load parameters to a finite element calculation server by utilizing wireless communication or the Internet of things to perform real-time calculation. The parameters comprise environmental load, temperature, wind speed and wind direction, vehicle weighing of weight load, intelligent recognition of the vehicle position by combining with a camera, and analysis of the weight load and the position.
3. And monitoring the display module. And constructing webpage end construction monitoring software at a monitoring display end by utilizing a front end webgl technology, acquiring a real-time calculation result of a server end by utilizing a network interface, globally displaying a finite element calculation result by combining a three-dimensional BIM model, and simultaneously monitoring the result states of all components to perform real-time safety early warning.
The following will explain the specific implementation procedure in this embodiment 1:
(1) Building bridge finite element model
Dividing the finite element units according to the design drawing, and considering the calculation precision and efficiency when dividing the finite element units. For the stress concentration or structure complex area such as the bottom of the main bridge tower, the bridge pier and the foundation connection, the small-size units are finely divided to accurately capture the mechanical response details, and for the parts with regular structure and uniform stress such as the equal-section beam sections, the unit size is properly increased, and the whole calculated amount is controlled.
And randomly generating a globally unique UUID code for each finite element unit by using an MD5 algorithm. The code is used as a special identification of the unit in the whole monitoring system, so that different units can be accurately distinguished and identified in links of data interaction, analysis and calculation and the like.
And carding out the sequence of the construction completion of each part of the bridge according to the construction scheme, and endowing each finite element unit with corresponding construction stage attributes according to the sequence. For example, in a bridge of cantilever casting construction, a segment unit constructed first corresponds to an earlier stage of construction, and a segment unit constructed later corresponds to a later stage. In this way, the system is able to dynamically track the state changes of each unit at different construction times.
And storing the constructed finite element model into a database, and distributing unique bridge identification codes to the finite element model. The identification code is like an 'identity card' of the model, and plays a key indexing role when the model is subsequently called, updated, related to other data and the like.
(2) Finite element unit and BIM model construction mapping
It is clear that each finite element uniquely corresponds to one BIM model member, and one BIM model member may correspond to the correspondence of a plurality of finite element elements. Because of the difference between the division modes of the finite element model and the BIM model, the finite element model divides units into very small units for realizing accurate mechanical simulation, and the BIM model is divided according to bridge components, for example, a pier is used as a component. Thus, each finite element may correspond to a unique BIM model member, and one BIM model member may correspond to a plurality of finite element elements. The mapping relation is the basis for realizing the visual display of the finite element calculation result and the BIM model.
BIM model data is read by using a Python script, an outsourced sphere is constructed from the first component, and the center coordinates and radius of the sphere are recorded. And (3) traversing all finite element units which are not mapped yet, calculating the distance from the finite element units to the center of the sphere, and screening out the finite element units with the distance smaller than the radius of the sphere as candidate units. The method can quickly reduce the screening range and improve the mapping efficiency.
And performing fine geometric calculation on the finite element unit to be selected and the BIM model component, and judging whether the BIM model component completely contains the finite element unit. And if the conditions are met, establishing a mapping relation, recording BIM model component codes in the finite element unit attribute, and storing the BIM model component codes in a database. The above operation is repeated by cycling through all the components of the BIM model until all the finite element elements have completed the mapping.
After the preliminary mapping is completed, the mapping result is verified, and whether mapping errors or omission exists is checked. The mapping relation can be visually displayed through a visualization tool, and the mapping of the abnormality can be manually adjusted. Meanwhile, a dynamic updating mechanism of the mapping relation is established, and when the finite element model or the BIM model changes, the mapping relation is updated in time, so that the accuracy and consistency of mapping are ensured.
(3) Determining stress warning threshold
And determining allowable stress through construction materials of bridge members, and further setting an early warning threshold value of each unit of the finite element.
And accurately acquiring construction material information of each component of the BIM through design information, and then consulting related material standards and specifications to determine the allowable stress of the material. The allowable stress of the material is a fixed value, which is determined according to the mechanical property of the material and the engineering safety requirement.
And searching the finite element unit corresponding to each BIM model component by utilizing the established mapping relation between the finite element unit and the BIM model component, setting allowable stress attributes for the finite element units, and storing the allowable stress attributes into corresponding fields of a database. Therefore, each finite element unit has corresponding allowable stress, and a basis is provided for subsequent early warning judgment.
And setting an early warning threshold value for each finite element unit, setting a three-level early warning threshold value for 65% -75% of allowable stress, setting a two-level early warning threshold value for 75% -85% of allowable stress, and setting a first-level early warning threshold value for 85% -95% of allowable stress, and storing the two early warning threshold values into corresponding fields of a database respectively. Different levels of early warning threshold values correspond to different risk degrees, so that potential safety problems can be found and processed in time.
And a dynamic adjustment mechanism of the early warning threshold is established in consideration of the fact that the material performance may be influenced by factors such as environment, time and the like in the construction process. And detecting and evaluating the materials regularly, and timely adjusting an early warning threshold according to the detection result to ensure the accuracy and reliability of early warning.
(4) Determining load variables
And determining the environmental load and the weight load to be considered in the construction process. Environmental loads include temperature, wind speed, wind direction, etc., and weight loads include the weight size and location of construction equipment, materials, etc. In the monitoring result database, unique ID numbers are respectively allocated to the load variables so as to accurately manage and inquire different types of load data.
The bridge identification code corresponding to each load variable is configured, so that when finite element calculation is performed, various load data corresponding to the bridge can be quickly and accurately inquired and obtained from a database according to the bridge identification code, and data support is provided for accurate calculation.
Binding an instrument code for collecting load data on a construction site with an ID number of a corresponding load variable. And (3) using a network interface to transfer real-time data collected by the instrument into a database at regular time according to a set time interval (such as 1 minute), so as to ensure timeliness and accuracy of load data.
And establishing a load data quality monitoring mechanism, and checking the accuracy and the integrity of the acquired data in real time. And marking and processing abnormal data such as data beyond a reasonable range, missing data and the like in time. The data quality can be monitored by setting a data threshold value, checking data continuity and the like, so that the reliability of the data used for calculation is ensured.
(5) A finite element computing server is configured to perform real-time computation
And starting a new finite element real-time calculation task at the server side, and transmitting a corresponding bridge identification code. And the server rapidly imports a corresponding bridge finite element model from the database according to the identification code, and is ready for subsequent real-time calculation.
And determining the finite element unit related to the current calculation requirement through the current bridge construction stage. By comparing the construction phase attribute of each unit with the current construction phase, if the construction phase of the unit is after the current construction phase, the unit does not participate in the calculation. Therefore, the calculated amount can be effectively reduced, and the calculation efficiency is improved.
And the server reads the latest load data comprising temperature, wind speed, wind direction, weight position and the like from the database according to the bridge identification code. The real-time and accurate load data are key input parameters for finite element calculation, and directly influence the accuracy of calculation results.
And setting a timing calculation mechanism, wherein the calculation interval time is set to be 2 seconds, so that the real-time performance of calculation is ensured. And when each calculation is performed, calculating by using the latest load data and the finite element units corresponding to the current construction stage, and updating the stress state of the bridge structure in time.
In order to improve the computing efficiency, computing resources of the finite element computing server are optimized and scheduled. Parallel computing techniques may be employed to simultaneously process multiple computing tasks using a multi-core processor or distributed computing cluster. Meanwhile, according to the priority and complexity of the computing task, computing resources are reasonably distributed, and the computing task can be efficiently completed.
(6) Finite element result display
Referring to fig. 3-6, finite element calculation results are obtained in real time on a front-end webpage, stress of each component of the three-dimensional BIM model is modified according to the results, the results are globally displayed, and the front-end webpage is communicated with a finite element calculation server in real time to obtain the calculation results. And dynamically modifying the stress display state of each component in the three-dimensional BIM model according to the calculation result. The stress can be intuitively expressed by adopting modes such as color gradual change, numerical value labeling and the like, so that constructors can quickly know the stress distribution condition of each part of the bridge.
In order to improve user experience, visual interaction functions are designed on the front-end webpage. For example, a user can view different visual angles and detailed information of the three-dimensional BIM model through operations such as clicking, zooming and rotating of a mouse, can select different construction stages to view stress distribution conditions of the stages, can locally amplify a specific area, and can analyze stress changes of the area in detail.
And adding a data statistics and analysis function on the front-end webpage, and carrying out statistics and analysis on the finite element calculation result. For example, calculating the statistical indexes such as the maximum stress, the average stress and the like of different construction stages, drawing a stress change curve, and intuitively displaying the change trend of the stress along with time and the construction stages. Through the analysis results, constructors are helped to better master the mechanical properties and the safety conditions of the bridge structure.
(7) Monitoring and early warning
The method comprises the steps of monitoring the stress state of each part of the construction bridge overall situation, setting a three-level early warning mechanism for monitoring and early warning, and obtaining the real-time stress of each finite element unit through real-time calculation by a server side and comparing the real-time stress with the three-level early warning value of the corresponding unit. And once the real-time stress reaches or exceeds the three-level early warning threshold, an early warning mechanism is immediately triggered.
If the early warning is triggered, the server side sends detailed early warning information to the front-end display interface, wherein the detailed early warning information comprises a finite element unit code, a finite element unit coordinate position, a real-time stress value, an early warning level and the like. Meanwhile, in order to ensure that the early warning information can be timely transmitted to related personnel, the early warning information can be sent to construction management personnel and technical personnel in a short message, mail and other modes.
After the front end receives the early warning information, a striking early warning mark is added at a position corresponding to the three-dimensional model according to the coordinate position. Setting a third-level early warning as a yellow mark to remind a worker of paying attention to the construction condition, setting a second-level early warning as an orange mark to remind the worker of taking necessary measures to reduce risks, and setting a first-level early warning as a red mark to warn the worker of emergently suspending construction and eliminating risks. Meanwhile, an early warning information list is arranged on the front-end webpage, all early warning information is displayed, and convenience is brought to constructors to check and process.
And establishing perfect early warning response and processing flow, and defining processing responsibility people and processing measures of early warning of different grades. When early warning occurs, relevant responsible persons should immediately process according to the processing flow, analyze the early warning reasons and take corresponding measures to eliminate potential safety hazards. And meanwhile, recording and tracking the early warning processing condition to form early warning processing closed-loop management.
Example 2
Referring to fig. 7, embodiment 2 provides a bridge construction global monitoring system based on finite element real-time calculation, which includes:
The finite element model construction unit is used for constructing a bridge finite element model, coding each finite element unit, guaranteeing the uniqueness of the codes, determining the bridge construction stage according to a construction scheme, endowing each unit with corresponding construction stage attributes according to the construction completion sequence of different parts, storing the constructed finite element model into a database, and distributing unique bridge identification codes;
The finite element and BIM model mapping unit is used for constructing a three-dimensional space geometric corresponding relation between the finite element model and the BIM model and mapping the finite element unit and the BIM model component;
The stress early warning threshold unit is used for determining allowable stress through construction materials of bridge members, so that early warning threshold values of each unit of the finite element are further set;
the load variable unit is used for determining load variables to be considered in the construction process;
the real-time computing unit is used for configuring the finite element computing server to perform real-time computation;
The finite element result display unit is used for obtaining a finite element calculation result, modifying the stress of each component of the three-dimensional BIM model according to the result and displaying the result globally;
and the monitoring and early warning unit is used for setting a three-level early warning mechanism and carrying out monitoring and early warning.
Example 3
Embodiment 3 also provides a computer readable storage medium, where a computer program is stored on the computer readable storage medium, where any step of the bridge construction global monitoring method based on finite element real-time calculation can be implemented when the computer program is executed by a processor.
The computer readable storage medium may include a U disk, a removable hard disk, a Read-Only Memory (ROM), a random access Memory (Random Access Memory, RAM), a magnetic disk or an optical disk, etc. various media that can store program codes.
For the description of the computer-readable storage medium provided by the present application, refer to the above method embodiments, and the disclosure is not repeated here.
It will be readily appreciated by those skilled in the art that the foregoing description is merely a preferred embodiment of the invention and is not intended to limit the invention, but any modifications, equivalents, improvements or alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.