CN210953191U - Discrete mechanical measurement system of multisensor - Google Patents

Abstract

The utility model discloses a discrete mechanics measurement system based on multisensor, including a plurality of sensors, still including supporting the side, it is a plurality of the one end of sensor is all connected support the side, it is a plurality of the other end of sensor is connected respectively in a plurality of measurement sides, and every it does not connect to throw out of gear between the measurement side. The utility model discloses have high accuracy, high stability, high reliable, low error, low cost, easy maintenance, low fault rate, need not to pair, environment and position strong adaptability, lightly small and exquisite, extension advantage such as nimble.

Description

Discrete mechanical measurement system of multisensor

Technical Field

The utility model relates to a mechanical measurement field especially relates to a discrete mechanical measurement system of multisensor.

Background

The problems of poor consistency, difficult debugging and balancing, heavy structure, poor environmental adaptability, low measurement precision, limited number of sensors which can be integrated in the same system and the like generally exist in the current multi-sensor mechanical measurement system.

Taking the most common pressure (weighing) system as an example, the common pressure (weighing) system has several modes, such as 4 sensors (mostly arranged in four corners in a shape like a Chinese character 'kou'), 6 sensors (mostly arranged in 6 dots in a shape like a Chinese character 'ri'), 8 sensors (mostly arranged in 8 dots in a shape like a Chinese character 'mu'), and the like, according to different factors, such as the measuring range, the tray area and the like.

The realization mode is characterized in that:

1. a plurality of sensors in the same system (such as the same ground scale) accumulate output voltage or current in a serial or parallel mode through a junction box (also called a concentrator, an accumulator and the like), and then output the accumulated analog quantity to an analog quantity input (AI) channel of instrument equipment for digital-to-analog conversion (ADC), calibration and other work.

2. Multiple sensors within the same system (e.g., the same floor scale) are rigidly (e.g., screwed, welded, glued, etc.) mounted to the same set of chassis, frame, connector, and/or tray.

Fig. 1 shows a typical connection mode of a conventional multi-sensor mechanical measurement system, in which a plurality of sensors 2 are connected to a terminal box 6, and after analog signals input by the sensors are superimposed by the terminal box 6, the analog signals are transmitted to an ADC device 8 through an AI channel 7 and converted into digital signals.

Fig. 2 exemplifies a weighing (pressure) system (side view) applying a prior art multi-sensor mechanical measuring system, wherein a plurality of sensors 2 are rigidly (usually bolts) fastened to the same measuring surface (weighing tray or the like, also called measuring side, or measuring end) 5 and supporting surface (chassis, frame or the like, also called supporting side, or supporting end) 3.

Fig. 3 is a drawing (side view) of a tension force system using a conventional multi-sensor mechanical measurement system. In which a plurality of sensors 2 are rigidly (usually bolts) fastened to the same measuring surface 5 (usually consisting of parts such as wire cables and connecting discs/plates, also called measuring side) and support surface 3 (usually consisting of parts such as wire cables and connecting discs, also called support side).

As can be seen from the tension system described in the above example, the support side and the measurement side thereof may be completely equivalent and interchangeable. For example: if the measuring surface 5 in the above example is considered as a support surface, its support surface 3 can also be considered as a measuring surface.

The main problems of the above structure are: the stress generated by the consistency and rigid connection of the sensor becomes an important reason for seriously influencing the measurement accuracy of the weighing instrument.

It is known in the art that, due to the manufacturing process, it is difficult to ensure similar consistency between different mechanical sensors in the same batch, the same model and the same measurement range.

For example, taking the pressure/weighing system described above as an example, even though two 8kg range pressure/load cells A and B of the same model are of the same lot, their voltage-weight (or current-weight) calibration curves may be quite different. For example, at 1 atm, 25 deg.C, and an excitation voltage of 3.3V, the output voltage of sensor A loaded with a 3kg load may be 3.2mV, while the output voltage of sensor B under the same conditions may be 2.6 mV. The final "voltage-weight" calibration curves for the two sensors may be shown in FIG. 4. The X-axis in the coordinate system of fig. 4 represents voltage, the Y-axis represents weight, the solid line is the "voltage-weight" calibration curve for sensor a of the previous example, and the dashed line is the "voltage-weight" calibration curve for sensor B. As can be clearly seen from fig. 4, the output voltages (or currents) of different sensors with different calibration curves are simply accumulated and then used as the input value of the AI channel of the instrument and meter, which has a great influence on the accuracy.

In the above example, when the input voltage of the AI channel is 5.8mV, the instrument cannot know whether the final value of 5.8mV is obtained from 3.2mV from the a sensor + 2.6mV from the B sensor, or from 3.2mV from the B sensor and 2.6mV from the a sensor, or from other combinations of 3.0mV from the a sensor and 2.8mV from the B sensor.

As can be seen from fig. 4, in the two most extreme cases of the above example, if the 5.8mV readings of the input AI channel are all from sensor a, then the true weight Ya2 of the current load should be 6.2 kg; conversely, if the 5.8mV current reading of the input AI channel is all from sensor B, then the true weight Yb2 of the current load should be 5.6 kg. Therefore, when we only know that the output superposition value of the sensor A and the sensor B is 5.8mV, we can only know that the real load is between 5.6kg and 6.2kg approximately, which obviously greatly reduces the overall accuracy of the weighing system.

This problem is called "offset error", i.e.: when the same object is placed at different positions of the scale or the same force is applied to the scale at different angles and/or positions, the readings may change.

The main current methods for solving the problem of the unbalance loading error are as follows: in the terminal box, 1 or 2 adjustable resistors (potentiometers) are added to each sensor, and the excitation (input) voltage and/or the output voltage of each sensor are adjusted respectively. However, this method still has the following disadvantages:

the nature of such adjustments is to approximate the input voltage and/or output voltage (or current) of the sensor plus a fixed constant value (of course, the constant could be negative); in other words, the method adds or subtracts a constant to or from the calibration curve shown in fig. 3 on the X axis and the Y axis, respectively.

It is clear that this approach only improves its consistency to a limited extent, and does not really allow multiple sensors to be tuned to be consistent. Fig. 5 simulates an optimal adjustment result for the situation described in the previous example by means of a terminal block. It can be seen therein that the deviations of the two sensors at zero and under light load conditions are calibrated, but that the deviations of them under high load conditions are amplified instead.

To put it back, even if a complex, non-linear calibration curve is idealized as a simple, linear straight line, it is clear that only addition or subtraction of a constant in the X-axis and Y-axis directions will not fit the problem of their different slopes.

In summary, the multi-path junction box for accumulating the output voltage or current of the sensors after the sensors are connected in series or in parallel has the following problems:

1. the precision is poor: the problem of unbalance loading errors caused by inconsistent calibration curves of the sensors cannot be solved, and the measurement precision is poor.

2. The pairing is difficult: due to the above problems, it is required that the shape of the calibration curve (or the slope thereof when the curve is idealized as a straight line) of a plurality of sensors operating in the same measuring system is kept as uniform as possible. However, in the existing production process, it is difficult to achieve such consistency between different sensors in the same batch and model. This results in:

a) the pairing cost is high: often a lot of work is required to find two sensors that can work in principle in pairs. It is even more difficult to pair 4, 8, 16 or even more sensors with each other.

b) Difficulty in maintenance: once one of a set of sensors is damaged, it is more difficult (often nearly impossible) to find a replacement that is paired with the other existing undamaged sensor. Therefore, in most cases, one sensor damages the whole measuring system and the whole measuring system is discarded.

3. The debugging is complicated: the consistency adjustment among a plurality of sensors is complex, and the sensors are often required to be debugged repeatedly one by one. The adjustment of the potentiometers tends to interact, for example: after the sensors a and B are debugged, the sensors a and C may be debugged, which may in turn destroy the consistency between the sensors a and B that have been previously debugged. Therefore, adjusting the terminal box potentiometer is a painful process that is fraught with repeated testing and weighing. And as the number of sensors increases, the complexity of the process can be dramatically increased geometrically.

In snow frosting, a mechanical sensor is generally sensitive to external factors such as temperature, humidity, air pressure and the like. These external factors further increase the complexity of the debugging and the adaptability of the system as a whole to the above-mentioned external environmental factors.

4. Extra noise: the junction box, as a device for superimposing and amplifying an analog signal, will undoubtedly add extra noise to the signal finally fed into the AI channel, thus affecting the measurement accuracy.

And the influence of external environments such as electromagnetic interference, temperature, humidity and the like further increases the unpredictability of noise, and causes negative influence on the overall working stability of the system.

For example: the stability of electronic devices such as potentiometers, triodes, resistors, capacitors, inductors, ICs, etc., and the disturbance caused by the above environmental influences all cause interference to the final output signal.

5. Extra failure: the junction box acts as an additional intermediary between the sensor and the analog-to-digital converter (ADC), introducing additional points of failure for the overall system.

6. The number of sensors is limited: since the more sensors cooperatively work under the same system, the more difficult the pairing, debugging and other work (geometrically), and the worse the overall measurement accuracy. The number of sensors within the same measurement system is therefore usually limited to only 8. This actually limits the application range in many occasions, and cannot configure an appropriate number of sensor matrixes according to actual requirements (measuring range, area, precision, etc.) to meet the requirements of measuring range, area, precision, etc.

Rigid connection between multiple sensors through the same chassis and/or frame and/or tray also presents a number of problems:

1. and strict balancing is needed among the plurality of sensors after rigid connection, otherwise, the problems of angular difference and the like are caused during measurement. Resulting in inaccurate measurement results. The trimming work is time consuming and cumbersome.

2. Even after a severe trim, each shift of the position usually results in errors again, requiring a re-trim. The workload is large.

3. Since the components such as the tray, the frame, and the chassis cannot reach an absolute rigid body and it is difficult to ensure an absolute level, a lever (seesaw) type or a mutual twisting type stress is generated between the sensors, resulting in a decrease in accuracy of the measurement result.

4. In order to approach the rigid body as much as possible, the tray, the frame, the chassis and other members are made of coarse steel or alloy materials which are as strong as possible. Not only wastes raw materials, but also causes the problems of heavy equipment, difficult transportation and maintenance and the like.

In summary, the conventional multi-sensor mechanical measurement system mainly has the problems of low precision, high cost, large workload, sensitivity to environment and position, difficulty in maintenance and the like.

On the other hand, the single-sensor measurement system has the disadvantages of limited range, poor adaptability to practical application scenes, small measurement range (for example, the maximum tray area measurable by a single weighing/pressure sensor is usually less than 50cm x 50cm, and if the maximum tray area is larger, the problem of overlarge angle difference is easily caused due to overlong arm of force), and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims at: the discrete mechanical measurement system of the multiple sensors has the advantages of high accuracy, high stability, high reliability, low error, low cost, easiness in maintenance, low failure rate, strong environmental and position adaptability, flexibility in expansion and light structure.

In order to realize the purpose, the technical scheme of the utility model is that:

a mechanics measurement system based on multiple sensors comprises sensors, a digital-to-analog conversion unit and a calculation unit; the sensors comprise a plurality of sensors, and each sensor is connected to the digital-to-analog conversion unit through a respective analog quantity input channel; the digital-to-analog conversion unit converts the data and transmits the converted data to the calculation unit; and the calculation unit is used for respectively carrying out primary calibration on the sensor corresponding to each analog input channel according to the signal transmitted by each analog input channel and carrying out secondary calibration according to the primary calibration result of all the sensors. The computing unit of the present invention can be a single or multiple digital computing devices with computing capability, including but not limited to: computer, single board computer, embedded industrial control equipment, FPGA, ASIC, DSP equipment, etc.

The utility model provides a discrete mechanics measurement system based on multisensor, includes a plurality of sensors, still includes the support side, and is a plurality of the one end of sensor is all connected the support side, it is a plurality of the other end of sensor is connected respectively in a plurality of measurement sides, and every it does not connect to measure between the side.

The "supporting side" may be (including but not limited to) any object that can support (support) and/or fix the sensor, such as a plane/curved surface (supporting surface/supporting plate/supporting pier), an end point (supporting end), a cable (supporting wire/bearing cable), a rod (supporting rod), a hook (bearing hook), a frame, a tray, and the like. And the "measurement side" can be, but is not limited to, any object that can help the sensor interface and/or carry its test load, including, but not limited to, flat/curved surfaces (measurement surface/measurement plate), end points (measurement ends), cables (measurement wires/load-bearing cables), rods (measurement rods), hooks (load-bearing hooks), frames, and trays.

Further, a plurality of the measurement sides are connected by a connection layer.

Furthermore, a buffer layer is arranged between the connecting layer and the measuring side.

A measuring method of a multi-sensor based mechanical measuring system comprises the following steps:

step 1, signals of a plurality of sensors are respectively transmitted to a digital-to-analog conversion unit through respective analog quantity input channels;

step 2, calibrating and calibrating each sensor once respectively;

and 3, carrying out secondary calibration according to the primary calibration results of all the sensors.

Further, the secondary calibration in step 3 includes the following steps:

step 3.1, carrying out conversion processing with any complexity on the output measurement value of each sensor after one-time calibration and calibration, and taking the processing result as an output value;

step 3.2, overlapping the output values in the step 3.1 and outputting an overlapped value;

and 3.3, further processing the superposition values in the step 3.2 by peeling, calibrating and converting with any complexity, and taking the processing result as the final result of secondary calibration.

Utility model advantage for prior art:

the utility model discloses owing to need not use concentrator or similar equipment, thoroughly got rid of the debugging that the concentrator brought with high costs, the precision is poor, pair difficult, extra noise, extra fault point and sensor quantity upper limit scheduling problem.

The utility model discloses because every way sensor all has own exclusive AI passageway for the system can carry out the accuracy respectively to every way sensor and mark, thereby keeps its accurate calibration curve respectively for every sensor, has effectively prevented that the mutual stack precision that brings of different calibration curves from misaligning and dispose difficult scheduling problem. In addition, the problems of difficult sensor pairing and the like in the processes of equipment production, maintenance and the like are also avoided. The system is also ensured to track and calibrate the deviation of each sensor caused by various internal and external factors such as temperature, humidity, air pressure, creep, condensation, dust, fatigue and the like in real time, so that each sensor is ensured to be calibrated accurately during initialization and can maintain stable and accurate operation for a long time in later use.

The utility model discloses because incoherent (linking to each other) between the sensor constitutes independent measuring unit separately, independently accomplishes the measurement (ADC, demarcation and calibration) work that belongs to the weight of oneself part for key elements such as its range, area become the system characteristic that can linear expansion, are showing and have saved the material, have reduced manufacturing cost, have reduced the product size, make the product light easy the deployment more.

The utility model discloses because its optional articulable articulamentum is flexible component, though theoretically also can produce stress (mainly mutual torsion) between different sensors after having implemented the articulamentum, because its stress is too weak, consequently can neglect usually.

Drawings

Fig. 1 is a schematic structural diagram of a conventional multi-sensor mechanical measurement system.

Fig. 2 is a schematic diagram of a pressure/weighing system using a conventional multi-sensor mechanical measurement system.

Fig. 3 is a schematic structural diagram of a tension force system using a conventional multi-sensor mechanical measurement system.

FIG. 4 is a calibration curve of "voltage-weight" for two sensors in a prior art multi-sensor mechanical measurement system.

FIG. 5 is a "voltage-weight" calibration optimization curve for two sensors in a prior art multi-sensor mechanical measurement system.

Fig. 6 is a schematic structural diagram of the mechanical measurement system based on multiple sensors.

Fig. 7 is a top view of a pressure/weighing system to which the present invention is applied.

Fig. 8 is a side view of fig. 7.

Fig. 9 is a schematic structural diagram of a tension system applying the present invention.

Fig. 10 is a schematic structural view of another embodiment of the tension system to which the present invention is applied.

Fig. 11 is a schematic structural view of another embodiment of a pressure/weighing system to which the present invention is applied.

Fig. 12 is a schematic structural view of a further embodiment of a pressure/weighing system to which the present invention is applied.

Fig. 13 is a schematic structural view of another embodiment of a tension system to which the present invention is applied.

Fig. 14 is a schematic structural view of still another embodiment of a tension system to which the present invention is applied.

Detailed Description

The embodiments of the present invention will be further explained with reference to the drawings.

Referring to fig. 6, a mechanical measurement system based on multiple sensors includes a sensor 2, a digital-to-analog conversion unit 8 and a calculation unit; the sensor 2 comprises a plurality of sensors, and each sensor 2 is connected to the digital-to-analog conversion unit 8 through a respective analog quantity input channel 7; the digital-to-analog conversion unit 8 converts the data and transmits the converted data to the calculation unit; the calculation unit respectively performs primary calibration on the sensor 2 corresponding to each analog input channel 7 according to the signal transmitted by each analog input channel 7, and performs secondary calibration according to the primary calibration result of all the sensors 2. The computing unit of the present invention can be a single or multiple digital computing devices with computing capability, including but not limited to: computer, single board computer, embedded industrial control equipment, FPGA, ASIC, DSP equipment, etc.

The primary calibration means that each sensor 2 has its own dedicated AI channel 7, so that the system can perform precise calibration for each sensor 2, thereby maintaining its precise calibration curve for each sensor 2. The problems of inaccurate precision, difficult configuration and the like caused by the mutual superposition of different calibration curves are effectively prevented. In addition, the problems of difficult sensor pairing and the like in the processes of equipment production, maintenance and the like are also avoided.

Moreover, the allocation of one or more AI channels (which can be used for other environmental sensors) to each sensor 2 also ensures that the system can perform real-time tracking and calibration work for each sensor, which is caused by various internal and external factors such as temperature, humidity, air pressure, creep, condensation, dust, fatigue, etc., respectively. The calibration of each sensor is ensured to be accurate during initialization, and long-term stable and accurate work of each sensor can be maintained during later use.

The process of quadratic scaling can be accumulated from simple arithmetic to arbitrarily complex expressions, or arbitrarily complex arithmetic and logical operation codes.

It should be noted that unless specifically stated otherwise, the term "calibration curve" is used herein in a generic sense, and the actual calibration may be performed by using various methods such as a straight line, a piecewise function, a curve (including but not limited to lagrange interpolation, newton interpolation, etc.), etc.

The discrete mechanical measurement system based on the multiple sensors has the advantages that the measurement sides of all the sensors in the system are separately arranged, so that the sensors are not coherent (connected) with each other, independent measurement units are formed respectively, and measurement (ADC, calibration and calibration) of components belonging to the sensors is completed independently. This effectively avoids the problems of angular differences and the like caused by the mutual stresses between the sensors.

Preferably, in general, a plurality of measuring units arranged in a discrete manner, without any additional mechanism, can naturally work together well in combination. In some special scenarios, however, a flexible or rigid connection layer may be added between the measurement units for reasons of aesthetics, equipment protection, or load friendliness.

Referring to fig. 7 and 8, a pressure/weighing system includes a plurality of sensors 2, and further includes a supporting surface (supporting side) 3, wherein the plurality of sensors 2 are all disposed on the supporting surface (supporting side) 3, and each of the sensors 2 is respectively provided with a measuring surface (measuring side) 1, where the measuring surface (measuring side) 1 is a tray.

Preferably, each of said trays is not connected to each other, which ensures that the measuring surfaces (measuring sides) of each sensor 2 are not mutually coherent (connected), each constituting an independent measuring unit, which independently performs the measurement (ADC, calibration and calibration) of the components belonging to its own part.

For pressure/weighing systems, each sensor 2 is typically fixed (individually) down (or up) to a support surface (support side) 3, respectively, which support surface 3 may be (including but not limited to) a concrete/steel concrete surface (e.g. concrete floor, ceiling); wood surface; a metal surface; a composite material surface; reinforced concrete beams/piers and the like; steel beams, keels, etc. of the building or shelf can secure any stable surface of the sensor.

The sensor 2 may be fixed to the support surface 3 by various means including, but not limited to, bolts (screws), bayonets, welding, gluing, etc., by any means including, but not limited to, washers, angle irons, profiles, etc.

On the top (or bottom) of the sensor, separate measuring surfaces (measuring sides) for carrying the actual load, such as mutually independent trays (or hooks, rods), are respectively fixed. The sensor 2 can be connected and fixed to the measuring surface (measuring side) 1 such as a tray in any manner.

Thus, each sensor 2 in the system constitutes a separate single-sensor weighing cell. In order to ensure independence in operation, independence between the individual weighing cells should be ensured. In particular, for a pressure/weighing cell using a tray, the tray of each sensor 2 should not come into contact with the trays of the other sensors 2 (other pressure cells). The two trays are preferably spaced apart by a distance of 1 to 50mm, depending on the actual situation.

Since the measuring surfaces (measuring sides) of the tray 1 and the like are incoherent (unconnected), even if all the sensors 2 are fixed on the same supporting surface 3 and it is clear that the supporting surface 3 does not meet the requirements of absolute rigid body, absolute level, absolute flatness and the like, the respective measuring accuracy of each pressure/weighing unit is not affected. This is because they are independent of each other, and thus, stress of various types such as lever (seesaw), mutual torsion, etc. described above is not generated due to load or other reasons. Therefore, the overall measurement accuracy is greatly improved.

However, it is obvious that the supporting surfaces (supporting sides) 3 are not too flexible, so that the measuring surfaces (measuring sides) such as the loaded trays 1 (or hooks) are brought into contact with each other by the deformation of the supporting surfaces 3, and coherence is generated due to the contact (connection) with each other. The support surface 3 should therefore still be as strong and stable as possible. However, it is obvious that the requirements of the present invention on the levelness, flatness and rigidity of the supporting surface 3 are greatly reduced.

Thus, in addition to the advantages described above, the present invention also allows for a substantial reduction in the size and weight of the measurement system. Conventionally, it is necessary to ensure as strong rigidity as possible (as little deformation as possible) and to keep as flat and level as possible in the components such as the tray, the support and the chassis, in order to avoid as much as possible the stresses that cause the various interferences between the sensors. It is clear that for a higher range, larger tray (pressure surface) area pressure/weighing system, it is more difficult (necessitating the use of thicker and stronger materials) to achieve the above-mentioned rigidity and flatness requirements. Therefore, the existing pressure/weighing system generally increases the weight, volume and other parameters of the product in geometric series along with the increase of the measuring range, the tray area and other properties.

For example: a pallet area 100x100cm (1 square meter), range 1000kg pressure/weighing system, typically much higher in volume and weight than the sum of 9 pallet areas 32x32cm, range 200kg measuring cells. Even the latter, after combination, has a measuring area of at least 1 square meter and a total measuring range of 1800 kg.

And the utility model discloses a separate the mode of back recombination once more with the measuring unit, avoided above-mentioned shortcoming completely. Elements such as the span and the area are made to be system characteristics capable of linear expansion. Namely: every doubling of range and/or area in a measurement system will only add the same proportion (one time) of volume and weight to the system at most, and will not increase its reference and/or weight in a geometric (exponential) manner. This not only saves material significantly, has reduced manufacturing cost, has reduced the product size. Simultaneously still greatly promoted product scalability and adaptability: the linear expansion of elements such as the measuring surface, the measuring range and the like can be freely realized according to the actual requirements of users.

Referring to fig. 9, in a multi-sensor tension measuring system composed of N sensors (of course, there are at least N AI channels), each sensor can be connected to a measuring end (measuring side) 1 (here, each measuring side is a wire rope) to form independent measuring side units. Each sensor is an independent measuring unit. Each measuring unit can measure its own tension component in a mutually incoherent manner.

Referring to fig. 10, due to the equivalent characteristics of the support end (support side) and the measurement end (measurement side) of the tension measuring system in the above-mentioned case (refer to fig. 3 and its related background description), it is fully possible to replace the support side with a connection device such as a separate wire rope. Each sensor is still a separate measurement unit at this time. Each measuring unit can still measure its own tensile force component in a mutually incoherent manner. And at the moment, the equality is restored between the supporting end (supporting side) 3 and the measuring end (measuring side) 1 in the tension measuring system.

Preferably, a plurality of the measuring sides (1) are connected to one another by a connecting layer (5).

In general, each sensor 2 forms an independent measuring unit, without any additional mechanism, which naturally can be well coupled together to work together. In some special scenarios, however, the connection layer 5 may be added between the measurement units for reasons of aesthetics, protection of equipment, or friendliness to loads. Referring to fig. 11, a connecting layer 5 is covered on a part or all of the trays of the measuring units. For example: in a set of multi-sensor discrete matrix weighing system with a total area of 100x100cm, which is formed by combining 9 independent measuring units with a tray area of 32x32cm in the form of a 3x3 array, a connecting layer can be deployed for the purposes of beauty, fine goods friendliness (seamless), protection of the weighing units and the like. Preferably, the connecting layer 5 is a flexible element, such as a 100 × 100cm rubber pad (or any soft material such as silicone, textile, fabric, etc.) laid on the surface of the tray 1. Soft materials such as rubber, textiles, etc. deployed in a flexible manner such as simple laying, etc. can theoretically also generate stress (mainly mutual twisting) between different weighing cells, but the stress is usually negligible because it is too weak.

Similarly, the connecting layer 5 may be (including but not limited to) a metal plate, a PP plate, a glass fiber reinforced plastic plate, an organic glass plate, a plywood, a density board, a wood plate, a PC plate, a PVC plate, and other hard large cover plates besides the soft material, so as to achieve the similar protection, beauty and other purposes. Preferably, a buffer layer 4 is arranged between the connecting layer 5 and the tray 1, as shown in fig. 12, and a more recommended arrangement is as follows: firstly, a buffer layer 4 made of rubber rings, rubber pads, PVC pads, springs, hydraulic mechanisms or other soft materials is paved on the measuring side (tray and the like) of each independent measuring unit, and then a whole hard large cover plate made of metal plates, glass fiber reinforced plastic plates and the like is paved on the buffer layer 4. This has the advantage that the intermediate damping layer 4 may act as a buffer and protection between the measurement side 1 of the tray or the like and the connection layer 5, since the tray is also usually made of a hard material such as metal.

In addition, this sandwich-type deployment has two additional benefits:

(100 x100cm in the above example) a large hard cover plate can transfer the load relatively more evenly to the various measurement cells in the system.

2. The soft material in the shape of a circular ring such as a rubber ring has a better mechanical distribution with respect to the force applied to the sensor by the load. After placing the annular rubber gasket on the square measuring cell tray, the tray is assumed to be square and the sensor is fixed in the center of the tray. The longest moment arm distance of the measuring unit is shortened from half the diagonal of the square to the radius of the rubber ring when the measuring unit is loaded. It is known that for a single sensor system, a smaller moment arm means a lower angular difference (this is equivalent to that the load can never be applied to the four corners of the tray because all four corners have been lifted by the rounded rubber pads). The integral precision of the system is improved, and meanwhile, the independent weighing unit with larger coverage area is favorably manufactured. Obviously, the above principle can be easily generalized to any of various polygons such as rectangles, parallelograms, ellipses, triangles, trapezoids, pentagons, hexagons, and other geometric shapes, in addition to squares.

In summary, after a sandwich-type flexible connection layer is added to the whole measurement system, although it is possible to introduce a small mutual stress between the sensors, the advantages of beauty, seamless (friendly to fine goods), durability, easy maintenance and the like can be obtained, and even due to the reduction of the angular difference of each weighing unit (the maximum moment arm is shortened), the whole measurement precision may not decrease or increase reversely.

Of course, in some special applications, it is also possible to rigidly fix some or all of the weighing cells. For example: one 100 × 100cm steel plate is fastened to the 9 measuring units in the above example by welding, screws, or other fastening means. It is clear that if good rigidity, levelness and flatness are not guaranteed, this way of fixing will generate strong stresses (both lever and cross-twist) between the sensors, and these stresses will likely become more pronounced as the system load is (unevenly) weighted. However, even in such a situation, the present invention still has significant advantages over the prior art:

1. the defects caused by the concentrator, such as poor precision, difficult pairing, complex debugging, extra noise, extra faults, limited sensor number and the like, are avoided.

2. Even if a rigidly fixed cover plate would introduce stresses and angular differences, it is simpler and more convenient to perform the calibration by a purely digital software system (rather than by a potentiometer in a junction box).

Further, even if a rigid connection is used, a sandwich structure similar to the previous one can be used, namely: a soft buffer layer 4 made of rubber and the like is added between each measuring unit tray and the integral cover plate. The buffer layer 4 still has the advantages of absorbing impact force, reducing the angle difference of each measuring unit monomer, and the like. Meanwhile, the buffer layer can absorb partial stress, so that the measurement result is more accurate.

Referring to fig. 13, a flexible or rigid connecting layer 5, which may be soft or hard, may also be added to the tension measuring system for multiple independent measuring systems. For example: fig. 13 shows an implementation of the connection layer 5 by adding a buffer layer 4 such as a spring, a hydraulic mechanism, etc. to each individual measuring end (measuring side) and twisting it into a loose large steel cable (flexible connection).

Referring to fig. 14, two ends of each measurement unit in the tension measurement system are respectively fixed on a steel plate in an elastic (hydraulic or spring, etc.) suspension manner, so as to implement a scheme that the flexible (spring) buffer layer 4 is butted with the hard (steel plate) connecting layer 5.

Or the two ends of each measuring unit are respectively fixed on the same corresponding reinforced concrete upright (two upright columns in total, N rigid fixing points on each upright column are connected with the steel cables at the same end of the N units, namely the rigid (fixing points) are butted with the hard (reinforced concrete upright) connecting layer), or the two ends of each measuring unit are respectively and directly fixed on a rubber plate (two rubber plates in total, N fixing points on each rubber plate are respectively connected with the steel cables at the same end of the N units, namely the rigid (fixing points) are butted with the soft (rubber plates) connecting layer, and the like, so that various arrangement combinations of soft/hard materials and flexible/rigid connection are implemented.

Of course, when it is necessary to add the connection layer 5, we still recommend to prefer to use a flexible connection that performs better, if not for any clear reason. However, as previously mentioned, even with the rigid connection of the unitary cover, the present invention provides significant advantages over the prior art.

After the flexible or rigid connection layers 5 on all the measurement units are implemented, the system can be subjected to overall secondary calibration (if the connection layers are not required to be implemented, the step can be skipped to directly perform secondary calibration). At this time, after non-goods loads such as rubber pads, springs, steel plates, containers (baskets and the like) are successfully deployed, the secondary calibration value obtained through the processing steps such as scaling, deviation, weighted accumulation, formula transformation and the like is the 0-point weight value of the current system. In other words, the superposed value after the connecting objects such as rubber pads, springs, steel plates, containers and the like are included is the integral 0-point value of the current measuring system.

After the 0-point value is determined, the calibration curve of the whole system can be determined by adding weights continuously and the like. If a rigid connection layer is used, it may be necessary to perform automatic or manual fine adjustment of the scaling factors, offsets, weights, etc. of the respective measurement units to eliminate the angular difference. In contrast, if a flexible connection reservoir is used or no connection layer is used, very high accuracy and small errors are typically achieved without the need for similar fine tuning. Of course, in case of very severe external conditions, such as lack of a sufficiently stable support surface, too rough support surface, large inclination of the measuring surface, etc., sometimes even if no rigid connection layer is used, it may occasionally be necessary to use the above parameters for fine adjustment of parts of the measuring cell.

It can be seen that the secondary calibration is mainly used for calibration on the system overall level, so that the problems of extra (non-cargo) load (peeling) caused by the connecting layer and the container are eliminated, and meanwhile, the problems of angular difference and the like caused by other external factors such as the rigid connecting layer and the like are corrected. The secondary calibration and calibration process plays a significant role in the final overall accurate measurement of the system.

A measuring method of a multi-sensor based mechanical measuring system comprises the following steps:

step 1, signals of a plurality of sensors 2 are respectively transmitted to a digital-to-analog conversion unit 8 through respective analog quantity input channels 7;

step 2, calibrating and calibrating each sensor 2 for one time respectively;

and 3, performing secondary calibration according to the primary calibration results of all the sensors 2.

Different from the primary calibration process, the secondary calibration is a process of taking the output force values of each sensor after primary calibration and calibration as input, performing secondary calibration and calibration on the input values, and finally outputting the overall measurement result value of the system.

In other words, the input of the secondary calibration is the output of each sensor after the primary calibration process, and the output of the secondary calibration can be used as the measurement result of the whole system for subsequent use and processing.

The secondary calibration process typically includes the following steps:

step 1, carrying out treatments such as scaling and offset on output measurement values of each sensor after one-time calibration and calibration, taking the treatment results as the current output values of the measurement unit, and participating in the next calculation. For example: the force value of each measurement unit may be converted, for example, into "scaling factor x measurement value + offset", where "scaling factor" and "offset" are both configurable items, either automatically configured by the system or manually configured by an administrator. Of course, the above formula is only an example, and in actual use, the measured value obtained from one calibration and calibration can be converted into an output value through any complicated-conversion. The conversion method can be either the formula of "scaling factor x measurement value + offset" or a script or program of arbitrary complexity.

And 2, overlapping the output values of all the measurement units in the current round. Here, "superposition" is not limited to simple arithmetic addition, but may also include (but is not limited to) various forms of superposition operations such as weighted accumulation, weighted sum of squares, weighted sum of mean squares, weighted cumulative mean square error, and the like. For example: a weighted sum algorithm containing N measurement units can be defined as follows: the superposition value is the weight 1x measurement unit 1 output value + the weight 2x measurement unit 2 output value + ·+ the weight N x measurement unit N output value.

And 3, further processing the superposition value generated in the second step, such as peeling, calibration, arbitrary complexity conversion and the like, and taking the processing result as the final result of the overall secondary calibration and calibration of the system. The transformation here can be either a formula such as "scaling factor x measurement + offset-tare" or a script or program of arbitrary complexity.

It is easy to see that in the utility model discloses in, no matter every sensor is used separately fixedly, and still flexible connection face or rigid connection face connect, its secondary calibration process, effect and notice are all similar, and its main function is:

1. the output values of the individual measuring units are superimposed in some way in a rational manner.

2. The measurement result deviation caused by additional stress, error, unbalance, balance weight, abnormal load (connection layer, container and the like) and other factors introduced in the processes of independently arranging and implementing the connection layer is eliminated and calibrated.

To sum up, the utility model discloses a no concentrator (terminal box) design, the discrete demarcation and calibration, the discrete arrangement, the secondary of every sensor independent access ADC are markd and are calibrated to and optional articulamentum, realized that mechanical measurement system is high accurate, high stable, high reliable, low error, low cost, easy maintenance, low fault rate, need not to pair, environment and position strong adaptability, lightly small and exquisite, the nimble advantage of extension.

It should be noted that although the embodiments of the present invention are only directed to pressure/weighing and tension measuring systems, the principles and concepts are obviously also applicable to various other mechanical measuring systems such as shear force, rotational force, horizontal force, friction force, supporting force, load force, etc. Use in including but not limited to above-mentioned all kinds of mechanical measurement systems the utility model discloses a method all belong to the utility model protection scope.

Claims (3)

1. The utility model provides a discrete mechanical measurement system based on multisensor which characterized in that: the device comprises a sensor (2), a digital-to-analog conversion unit and a calculation unit; the sensor (2) comprises a plurality of sensors, and each sensor is connected to the digital-to-analog conversion unit through a respective analog quantity input channel; the digital-to-analog conversion unit converts the data and transmits the converted data to the calculation unit; the discrete mechanical measurement system with the multiple sensors further comprises a supporting side (3), one ends of the sensors (2) are connected to the supporting side (3), the other ends of the sensors (2) are connected to the measuring sides (1) respectively, and each measuring side (1) is not connected with the other end.

2. The multi-sensor based discrete mechanical measurement system of claim 1, wherein: the measuring sides (1) are connected by a connecting layer (5).

3. The multi-sensor based discrete mechanical measurement system of claim 2, wherein: a buffer layer (4) is arranged between the connecting layer (5) and the measuring side (1).

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