Summary of the invention
Technical problem to be solved in the utility model provides a kind of dynamic sole pressure test insole with multilayer sensing core structure, overcome the PVDF piezoelectric film sensor as the problems referred to above that sensing core structure produced, the shoe-pad that embeds multilayer sensing core structure thin film sensor unit can be used for the dynamic test of optional frequencies such as human locomotion, running, jump, and can combine convenient the use with the footwear of everyday general purpose.
The technical scheme that its technical problem that solves the utility model adopts is: a kind of dynamic sole pressure test insole with multilayer sensing core structure is provided, comprise shoe-pad, signal condition unit, data acquisition unit and signal display unit, embed sensing core structure thin film sensor unit in the described shoe-pad; Described sensing core structure thin film sensor unit is formed by stacking up and down by two-layer at least PVDF piezoelectric membrane; One deck hard synthetic material film is arranged between described sensing core structure thin film sensor unit and the shoe-pad contact-making surface; Described sensing core structure thin film sensor unit links to each other with signal condition unit, data acquisition unit and the signal display unit of series connection successively.
Described sensing core structure film-sensing unit with dynamic sole pressure test insole of multilayer sensing core structure is converted to charge signal with the plantar pressure signal that collects and is transferred to the signal condition unit; Described signal condition unit is converted to voltage signal with the charge signal of receiving and is transferred to data acquisition unit; Described data acquisition unit is transferred to signal display unit with the voltage signal of receiving.
Described signal condition unit with dynamic sole pressure test insole of multilayer sensing core structure is in series by integrating amplification circuit and low-pass filter circuit, and signal is introduced into described integrating amplification circuit and enters described low-pass filter circuit again.
The multilayer sensing core structure thin film sensor cell distribution of described dynamic sole pressure test insole with multilayer sensing core structure is on described shoe-pad upper left-hand, upper right, left side, middle part, right side, middle part, lower left side and right side, bottom.
Described hard synthetic material film with dynamic sole pressure test insole of multilayer sensing core structure is hard PVC film, hard PE film or hard PET film.
Beneficial effect
Owing to adopted above-mentioned technical scheme, the utility model compared with prior art has following advantage and good effect:
(1) effective area of single sensing unit is less, can improve the resolution ratio that the test plantar pressure distributes.The multilayer PVDF piezoelectric membrane sensing core structure that is adopted has realized under the situation that does not change the sensing unit surface area improving the intensity of output signal.
(2) between the PVDF piezoelectric membrane of multilayer sensing core structure thin film sensor unit and substrate shoe-pad, embed the synthesis material film of hard as interval insulant, with the influence that the insole material that intercepts the dynamic frequency difference in response produces the piezoelectric membrane signal, reduce the signal lag that the elasticity creep because of flexible insole material is brought.
(3) the follow-up modulate circuit of sensor is made of integrating amplification circuit and low-pass filter circuit.The required element of this circuit is few, volume and quality are less, and the integration amplification effect can be regulated by component.Main element comprises integral amplifier OP07, feedback capacity C and feedback resistance R, test voltage scope 0~10V, the about 0.16Hz of the lower-cut-off frequency of circuit test.The low-pass filter circuit that adds behind integrating amplification circuit has been avoided the influence of test high-frequency noises signal.
In sum, the utility model adopts the design of multilayer sensing core structure and interval insulant film, has improved the signal to noise ratio of PVDF piezoelectric film sensor, has improved the hysteresis quality of sole pressure test system to the Dynamic Signal response.The native system test frequency is wide, is adapted to the test that the plantar pressure under the asynchronous frequency motion state of human body distributes.Meanwhile the wearable property of the utility model is good, shoe-pad softness, flexible, and material is light, thin, and human body is comfortable and easy to wear.The utility model not only can be tied to the vola and carry out naked sufficient pressure test, also can put into the various footwear of everyday general purpose and test, and the biomechanical analysis and the footwear Comfort Evaluation that can be body gait provide foundation.
Description of drawings
Fig. 1 plantar pressure distribution tests shoe-pad system schematic,
Among the figure, 1 shoe-pad, 2 signal condition unit, 3 data acquisition units, 4 signal display units, 5 sensing core structure thin film sensor unit;
Fig. 2 is signal condition element circuit figure;
Fig. 3 is sensing point vola (right crus of diaphragm) distribution schematic diagram,
Among the figure, 6 is first metatarsal bone, and 7 is second metatarsal bone, and 8 is inboard in the foot, and 9 is the outside in the foot, and 10 is heel medial, outside of heel;
Fig. 4 is the sensing shoe-pad schematic diagram that embeds the multilayer sensing core structure thin film sensor;
A: multilayer PVDF film
B: hard synthetic material film
Fig. 5 is the response diagram of system to the 1.5Hz Dynamic Signal;
Maximum pressure F=50N, frequency f=1.5Hz;
Fig. 6 is the response diagram of system to 5.0Hz frequency dynamic signal;
Maximum pressure F=200N, frequency f=5.0Hz;
Vola dynamic pressure distribution measured waveform figure when Fig. 7 is human body walking
Step is 2.0Hz frequently, and each curve representative characteristic point distributes signal as C.
The specific embodiment
Below in conjunction with specific embodiment, further set forth the utility model.Should be understood that these embodiment only to be used to the utility model is described and be not used in the restriction scope of the present utility model.Should be understood that in addition those skilled in the art can make various changes or modifications the utility model after the content of having read the utility model instruction, these equivalent form of values fall within the application's appended claims institute restricted portion equally.
Embodiment of the present utility model relates to a kind of dynamic sole pressure test insole with multilayer sensing core structure, as shown in Figure 1, comprise shoe-pad 1, signal condition unit 2, data acquisition unit 3 and signal display unit 4, embed sensing core structure thin film sensor unit 5 in the described shoe-pad 1; Described sensing core structure thin film sensor unit 5 is formed by stacking up and down by two-layer at least PVDF piezoelectric membrane; Between described sensing core structure thin film sensor unit 5 and described shoe-pad 1 contact-making surface one deck hard synthetic material film is arranged; Described sensing core structure thin film sensor unit 5 links to each other with signal condition unit 2, data acquisition unit 3 and the signal display unit 4 of series connection successively.Described sensing core structure thin film sensor unit 5 is converted to charge signal with the plantar pressure signal that collects and is transferred to signal condition unit 2; Described signal condition unit 2 is converted to voltage signal with the charge signal of receiving and is transferred to data acquisition unit 3; Described data acquisition unit 3 is transferred to signal display unit 4 with the voltage signal of receiving.
Described signal condition unit 2 with dynamic sole pressure test insole of multilayer sensing core structure is in series by integrating amplification circuit and low-pass filter circuit, and signal passes through low-pass filter circuit again by integrating amplification circuit earlier.As shown in Figure 2, the required element of described integrating circuit is few, volume and quality are less, and the integration amplification effect can be regulated by component.Main element comprises integral amplifier OP07, feedback capacity C and feedback resistance R, test voltage scope 0~10V, the about 0.16Hz of the lower-cut-off frequency of circuit test.The low-pass filter circuit that adds behind integrating amplification circuit has been avoided the influence of test high-frequency noises signal.
Described multilayer sensing core structure thin film sensor unit 5 with dynamic sole pressure test insole of multilayer sensing core structure is distributed in described shoe-pad 1 upper left-hand, upper right, left side, middle part, right side, middle part, lower left side and right side, bottom.As shown in Figure 3, be example with the right crus of diaphragm, shoe-pad 1 upper left-hand is corresponding to first metatarsal bone 6, upper right is corresponding to second metatarsal bone 7, and the left side, middle part is corresponding to inboard 8 in the foot, and the right side, middle part is corresponding to the outside 9 in the foot, lower left side is corresponding to heel medial 10, and the right side, bottom is corresponding to outside of heel 11.Because the sensing core structure thin film sensor cell distribution that multilayer PVDF piezoelectric membrane is formed corresponding to each relevant position in vola, can provide the plantar pressure signal at PVDF piezoelectric membrane place in each position of shoe-pad in real time.
Described hard synthetic material film with dynamic sole pressure test insole of multilayer sensing core structure is hard PVC film, hard PE film or hard PET film
Core of the present utility model is to have the sensing shoe-pad that the dynamic plantar pressure of test distributes, and as shown in Figure 4, it is formed by stacking up and down by two-layer at least PVDF piezoelectric membrane, forms multilayer sensing core structure thin film sensor unit, is embedded on several positions in the shoe-pad.Between sensing core structure thin film sensor unit and shoe-pad contact-making surface, embed the hard synthetic material film, avoided the hysteresis quality of sensing core structure thin film sensor unit the Dynamic Signal response.When pressure put on PVDF piezoelectric membrane surface, the PVDF piezoelectric membrane of each layer was converted to pressure signal charge signal output simultaneously.
Below in conjunction with the furthermore bright the utility model of embodiment.
Embodiment 1
The sensing core structure thin film sensor unit that adopts 3 layers of PVDF piezoelectric membrane to form embeds the hard PVC film between film and shoe-pad.Under low frequency, low-pressure active force, promptly simulate the slowly state of walking of human body, this moment, test macro was to the response than the Dynamic Signal of small frequency and pressure.
Specimen: embed the shoe-pad of the sensing core structure thin film sensor unit of PVDF piezoelectric membrane composition, single sensing unit.
Tester: MTS dynamic tensile instrument, the contact presser feet of configuration simulation human body vola material.
Test condition: signal frequency is 1.5Hz, exerts pressure to be 50N.
Test result: as shown in Figure 5.Under low frequency, low-pressure effect, the system output signal waveform stabilization.Owing to adopted 3 layers of PVDF piezoelectric membrane, sensor still shows stronger frequency response under than the weak pressure effect, and signal peak reaches 80mV, and signal to noise ratio is greater than 25dB, effective voltage peak value characteristic remarkable.Show that system still can collect discernible useful signal at lower pressure position, vola.
Embodiment 2
The sensing core structure thin film sensor unit that adopts 2 layers of PVDF piezoelectric membrane to form embeds hard PE film between film and shoe-pad.Under high frequency, high pressure effect, promptly simulate the human foot high-speed motion, test macro is to the frequency response of the collection of vola Dynamic Signal at this moment.
Specimen: embed the shoe-pad of the sensing core structure thin film sensor unit of PVDF piezoelectric membrane composition, single sensing unit.
Tester: MTS dynamic tensile instrument, the contact presser feet of configuration simulation human body vola material.
Test condition: signal frequency is 5.0Hz, exerts pressure to be 200N.
Test result: as shown in Figure 6.Under high frequency, high pressure effect, the system output signal waveform stabilization, frequency-response characteristic is remarkable, and the signal coefficient of variation is below 5.0%, and hysteresis quality improves.Show the stability of system to upper frequency plantar pressure signal response, the shoe-pad that embeds 2 layers of sensing core structure PVDF piezoelectric film sensor unit is suitable for the plantar pressure of testing human under going on foot frequently arbitrarily and distributes.
Embodiment 3
System is in the plantar pressure distribution tests of normally wearing under the condition, and the plantar pressure the when pressure signal that is collected by a plurality of sensing unit of shoe-pad can be to human locomotion distributes and is described.
Specimen: embed 6 pieces of shoe-pads, between every piece of thin film sensor unit and shoe-pad, embed hard PET film with sensing core structure thin film sensor unit of 5 layers of PVDF piezoelectric membranes composition.
Test condition: test is carried out indoor, and the shoe-pad that embeds 5 layers of sensing core structure PVDF piezoelectric film sensor is placed in the flat sport footwear to be worn, and the signal condition unit is fixed in tester's shank, and the step is about 2.0Hz frequently.
Test result: as shown in Figure 7.Normally wearing under the condition, system works is stable, and the signal response frequency that is obtained was coincide frequently with the actual step, and vola each point signal characteristic is remarkable, and resulting dynamic plantar pressure distributional pattern is representative.By writing down same individual normal gait, the synchronised many groups plantar pressure signal under frequently, the maximum plantar pressure peak is added up, can obtain the certainty of measurement of system, promptly percent error reaches 2.3% relatively, satisfies the specification requirement of plantar pressure distribution measuring product.
Be not difficult to find that the utility model adopts the design of multilayer sensing core structure and interval insulant film, improved the signal to noise ratio of PVDF piezoelectric film sensor, improved the hysteresis quality of sole pressure test system the Dynamic Signal response.The native system test frequency is wide, is adapted to the test that the plantar pressure under the asynchronous frequency motion state of human body distributes.Meanwhile the wearable property of the utility model is good, shoe-pad softness, flexible, and material is light, thin, and human body is comfortable and easy to wear.The utility model not only can be tied to the vola and carry out naked sufficient pressure test, also can put into the various footwear of everyday general purpose and test, and the biomechanical analysis and the footwear Comfort Evaluation that can be body gait provide foundation.