The utility model relates to a kind of measurement mechanism of the sportsman's of being used for dynamometry, particularly relates to the sensor of measuring size, direction and the center of effort of acting force between sportsman and force plate/platform.
In numerous sports items, numerous items is arranged, athletic achievement is closely-related with his process of having an effect of final jump.For example in jump event, high jump and long-jump under the condition that sportsman's run-up speed and leg power are determined, when athletic achievement depends primarily on last take-off, sportsman have an effect distribution on all directions and the length of action time.Under the condition of determining (mainly referring to athletic having an effect, action time, take-off speed etc.), there is a the best to set out at the condition of sportsman own, this moment, the sportsman was expected to obtain optimum achievement.And this optimum achievement is can be by the size and Orientation of having an effect, the length of action time, power change procedure curve, calculation of parameter such as point of force application track variation are come out with simulation, that is to say by these parameters, can access the standard procedure that the sportsman can obtain this process of best result, the process of training athlete just should make the action of oneself approach this standard procedure as far as possible.
The athletic training of China at present lacks special-purpose testing apparatus mainly by rule of thumb, mainly is technological means and the sensor that lacks test, and the sportsman does not have some definite data for analyzing and research in training process.Be exclusively used in all one's effort test board product of sports, at home and abroad do not see as yet at present, only have some to be used for the three-dimensional force test platform of industry and physical culture.The most influential best brand of product is the piezoelectric type dynamometric system of Switzerland Kistler company in the world at present, secondly is the dynamometric system of the resistance-strain chip of U.S. AMTI company.Domestic also have the experiment of a few family units to produce this type of ergograph, and as Tsing-Hua University, Dalian University of Technology etc., they mainly are the products of copying Switzerland Co., Ltd.
Sensor is the core of force plate/platform, and the quality of its performance is related to the purposes and the value of entire measuring device.At present, the sensor of used both at home and abroad force plate/platform is by following several forms:
1. adopt four three-dimensional piezoelectric force transducers
Four three-dimensional piezoelectric force transducers are installed on four angles of base plate, and pedal then is installed in the force side of four sensors, utilize the output of four sensors to calculate six output quantities of force plate/platform.The scheme of four three-dimensional force sensors of this employing has following characteristics:
1. power is calculated fairly simple, in its ideal model six of force plate/platform output be certain several amount in measured 12 force components and, or certain several amount and product fixed range, that is to say to be the arithmetic result of measured 12 force components.
2. because four sensors are relatively independent, the size of force plate/platform is only relevant with the size of pedal, and do not have direct relation with sensor, so the size of force plate/platform can formulate plurality of specifications according to user's demand, and be unlikely to influence whole process of production.
3. be mounted on same pedal and the same base plate owing to four sensors, may there be bigger acting force between each sensor when therefore installing, this experience with method program of installing, debugging and installation personnel is relevant, in general, bigger initial action power can influence the precision and the use of whole force plate/platform system.
4. because pedal and base plate have bigger temperature contrast in actual use, therefore, the distance between the sensor of installing on pedal and the base plate may change, and forms temperature variant initial action power, therefore on system, may there be bigger zero point drift in this scheme.
5. the force transducer that adopts piezoelectric to do, nearly zero end of its frequency response descends serious, is unwell to and does static test and demarcation.
2. adopt four three dimensional strain formula sensors
Adopt four three dimensional strain formula sensors, this type of sensor is identical with above-mentioned piezoelectric transducer basically on principle, but does not have the problem of the nearly zero end decline of frequency response.Popular multidimensional power test platform is mostly combined by four three-dimensional force sensors at present, so the structure more complicated, price is also very expensive.
The objective of the invention is to adopt robot rood beam shape six-dimension force sensor as sportsman's force plate/platform, this device mainly be at the relevant motion of process of having an effect of fixed point foot, as motions such as high jump, long-jump, the start of a race, divings.In the sportsman has an effect the process that acts on to ground, all processes that utilizes multi-dimension force sensor to come continuous recording to have an effect and act on.The form of mechanism with curve of having an effect shown, and as the trainer, the sportsman understands the foundation of this process, makes training scienceization.Be expected to improve significantly athletic sports achievement, for China's sports business development plays a driving role.
Technical scheme of the present invention is: a kind of force plate/platform, comprise base plate (1), power pack (2), strain beam (3), central block (4), floating beam (5), pedestal (6), pedal (7), cutting ferrule (8), and it is characterized in that:
The structure of force plate/platform is a sensor elastomer rood beam type, and rood beam is positioned on the central block (4), and the center of central block (4) is a square hollow;
Pedestal (6) is fixed on the base plate (1) by screw, it is other that power pack (2) is fixed on pedestal (6), the middle mounting center piece (4) of pedestal (6) also has the screw sensor installation, four strain beams (3) and four floating beams (5) are installed on four diagonal angles of central block (4), be coated with screw fixing pedal (7) and cutting ferrule (8) on the central block (4), paper tinsel formula foil gauge is installed on each face of strain beam (3) forms the strain bridge circuit, obtain corresponding sextuple power/moment output by output decoupling with the strain bridge circuit;
Described sensor elastomer is an integral body, and strain beam (3), central block (4) and pedestal (6) all are to be formed by a metal material processing.
The beneficial effects of the utility model are:
1. sensor elastomer is an integral body, and strain beam central block and pedestal all are to be processed by a block of material, so its material is identical, and contact closely realizes one of performance and the temperature equilibrium of making peace easily in inside, and the zero point drift of sensor etc. are less;
2. owing to be whole processing, its Installation and Debugging are comparatively simple with respect to other scheme, are unlikely to cause because install improper serious problems;
3. its data acquisition and processing (DAP) can help eliminating various linear errors with reference to the mature experience of sextuple wrist force sensor, improves precision.
4. sensor is four dimension sensors in itself, therefore when internal force is big, can adopt subregion calibrated and calculated method to eliminate the error that internal force causes.
5. ultimate principle and the basic structure with six-dimension force sensor applies to force plate/platform, solved because force plate/platform load big (maximum range 1.2T), big (the 400mm * 400mm) of lifting surface area, with singularity such as stress point dispersions and a series of problems of in structural design and calibration process, bringing, develop the force plate/platform of single six-dimension force sensor, advantages such as force plate/platform is simple in structure, and physical concept is clear are that general knockdown force plate/platform is incomparable
6. force plate/platform adopts portable construction, and the total data disposal system is integrated in the suitcase, and is equipped with the AC/DC double-purpose electric source, is specially adapted to the execute-in-place in varying environment.
7. the P/C of this force plate/platform is than high, and external similarly force plate/platform price asked is generally at the hundreds of thousands dollar, and domestic imitation products is also asked a price more than 70,000 Renminbi.The force plate/platform main performance index reaches the advanced level of external like product, performance then is better than external product, but price is below 1/tens of external product only, is lower than domestic imitation products, and general sports and scientific research unit, universities and colleges and sports team all might accept.
Below in conjunction with accompanying drawing embodiment is elaborated.
Fig. 1 is a force plate/platform elastic body shape assumption diagram.
In the accompanying drawings, pedestal 6 is frameworks of a rectangle, can be porose on framework or screw be used for installing, central block 4 is as afterburning part, can be porose on central block 4 or screw be used for installing pedal, four floating beams 5 are arranged on four jiaos of pedestal 6, and between the center of four floating beams 5 and central block, there are four strain beams 3 to link to each other respectively with pedestal 6, on four faces of each strain beam 3, all post foil gauge, be used for measuring the strain of the strain beam that the external force effect causes.When acting force is added on the central block 4, the resistance of the foil gauge on four strain beams 3 changes, through suitable group bridge, can measure three force component Fx, Fy, Fz and three moment components Mx, My, Mz, wherein Mx and My can be used for calculating respectively the value of Y, X, the just position of point of force application.The effect of floating beam 5 is that increase strain beam 3 is flexible longitudinally, the sensitivity that improves Fx, Fy.
Elastic body and strain bridge circuit partly are the critical components of dynamometric system, by it the power that is subjected on the platform are transformed into electric signal output.It mainly is made up of central block 4, strain bridge circuit and the power circuit of pedal 7, elastomer portion.Pedal 7 is one flat plates, and it passes through eight screw retention on elastomeric division center.Yun Dong type as required, it can select aluminium alloy plate for use, plank or vulcanie plate (or plastic plate), its effect is that the power of will bear sends elastic body to.Elastic body is a steel, external dimensions is the square platform of 400cm * 400cm * 20cm, the rood beam structure is adopted in the core, the rood beam structure is the square mesa that there is cavity a centre, stretching out four strain beams 3 on four angles of square mesa links to each other with elastomeric external structure, to transmit the external force of coming by pedal 7 by square mesa, pass to rood beam.Upper and lower, left and right at each strain beam of rood beam are posted two foil gauges on four sides, post 32 paper tinsel formula foil gauges on four beams altogether, form 8 groups of strain bridge circuits, and when rood beam generation strain, the strain bridge circuit has corresponding electric signal output.These electric signals are transformed into corresponding sextuple power/moment information through decoupling zero.Elastomeric external structure is the supporting surface of rood beam platform.The bridge circuit power circuit for eight road and bridge the road stable working power is provided, power pack 2 is placed in the cavity of platform.
Force plate/platform needs indoors, can both work easily in the open air, so the power supply of force plate/platform must possess following characteristics:
1) do not having under the external power supply condition of (comprising the AC and DC power supply), force plate/platform needs and can operate as normal be no less than 1 hour.
2) can use the continuous operate as normal of AC power of 220V/50Hz.
3), can be the internal power supply charging with the 220V AC power easily without any need for external unit.
According to the requirement of force plate/platform to power unit, power unit adopts a group storage battery as primary power, and light warning is arranged when battery tension is lower than ultimate value.Provide the output of many group direct supplys by the DC-DC conversion.AC power is as accessory power supply, and under the situation of AC power work, on the one hand by transformation, rectification, voltage stabilizing and DC-DC conversion, it is the D.C. regulated power supply outputs of organizing that alternating current is delivered more, and battery feed transfers charged state automatically on the other hand.When force plate/platform is not worked, but under the situation that AC power exists, accumulator also is in charged state.
Sensor is to be processed by a block of material integral body, and therefore, material can guarantee that with performances such as thermal treatments four strain beam performances of this sensor are consistent, has improved the precision of force plate/platform greatly.