A kind of active light source formula crop canopies reflective spectral measure device
Technical field
the utility model relates to a kind of structural design of the crop canopies reflectance spectrum the cannot-harm-detection device light path system based on active light source, belong to geometrical optics technical design field, but it possesses the specific characteristic of special application field, especially the form of its optically focused, the array configuration of detecting unit and version, embody spy's card of Agricultural Information field of non destructive testing, specifically a kind of narrow-band LED active light can being accumulated has the special geometric feature, be fit to the banded light that crop canopies detects, and the canopy reflected light is converted to the optical de-tection means of the photosignal of being convenient to detect.In conjunction with the plant growth information model, measured value can be converted into various plant growth indexs, the diagnosis of realization to plant growth information can be used at crop alimentary State Diagnosis and accurate agricultural variable fertilising field, be the present modern agricultural in the urgent need to the Agricultural Information equipment.
Background technology
at present, utilize the crop canopies diffuse reflection spectrum to obtain the important research direction that plant growth information is the Agricultural Information field, Chinese scholars has had very deep and research widely to the mechanism relation between diffuse reflection spectrum and relevant plant growth information, studies show that in a large number: utilize the canopy spectra analytical technology can effectively realize the dynamic monitoring of plant growth feature and nutrition status of the plant, difference vegetation index wherein, the spectrum index such as normalized differential vegetation index and ratio vegetation index is widely used in the plant leaf area index, Dry Matter Production, Leaf N content and nitrogen accumulation, blade carbon-nitrogen ratio and output estimation, nutrition condition than traditional physics and biochemical method research crop, the canopy spectra analytical technology has fast, portable, harmless, be not subjected to the outstanding advantages such as space-time restriction, the IT application to agriculture field in the urgent need to technological means.But the mechanism relation between canopy spectra reflective information and plant growth information is carried out through engineering approaches to be realized and is applied to that the field is measured in real time and the real-time instruction agricultural production is present weak link, substantially be in conceptual phase and the on probationization stage, not yet effectively used in actual agricultural production.
The growth information index that adopts canopy reflectance spectra sensing technology (Ground-based Canopy Reflectance Sensing) to obtain crop is focus and the important means of current this area research, and the way of realization of such technology mainly contains two kinds: passive light-source type and active light source formula.Passive light-source type surveying instrument utilizes sunshine as detection light source, its maximum limitation is the impact that its use is subject to the factors such as Intensity of the sunlight, solar incident angle, its measured value also can change because of the variation of natural light environment, use in the time of generally need to and having larger solar angle at fine weather, overcast and rainyly can't use.Active light source formula instrument carries the light source that can launch specific wavelength, and the luminous of light source can be eliminated the impact of exterior light environment through high frequency modulated, can use under any weather condition and natural lighting condition, and active light source formula instrument is present main flow form.
Summary of the invention
The purpose of this utility model is to realize the measurement based on the canopy reflectance spectra of active light source, a kind of active light source formula crop canopies reflective spectral measure device is proposed, utilize this structure can realize that the light path parameter of active light source is adjustable, to adapt to the measurement to the different scale canopy reflectance spectra, strengthened the operability of measurement mechanism.
The technical solution of the utility model is:
A kind of active light source formula crop canopies reflective spectral measure device, it comprises the light path transmitter unit that light path system mounting base, LED installation positioner, cylindrical mirror erecting frame and cylindrical mirror consist of, and at least one group of light path detecting unit that is consisted of by spectral detection light path mounting hole, plano-convex lens, optical filter and photoelectric sensitive device, wherein the type of optical filter and LED light emitting array is Wavelength matched; Be provided with parallel spectral detection light path mounting hole and light belt shaping groove on described light path system mounting base, plano-convex lens is arranged in spectral detection light path mounting hole, the LED installation positioner is arranged on the steady arm mounting groove at the light path system mounting base back side, this LED installation positioner is platy structure, built-in several are used for installing the LED mounting hole of LED light emitting array, the cylindrical mirror erecting frame embeds in the lower square groove of the light belt shaping groove be arranged on light path system pedestal front, and cylindrical mirror is arranged on the cylindrical mirror erecting frame; In described spectral detection light path mounting hole, the rear end of plano-convex lens sets gradually optical filter and photoelectric sensitive device, and described photoelectric sensitive device output voltage signal is supplied with the rear class treatment facility.
Clamp the adjusting pad between light path system mounting base of the present utility model and light belt shaping groove, can regulate the structural parameters of light path system by the adjusting pad that clamps different-thickness.
LED mounting hole of the present utility model is the inclined hole with certain inclination angle; The LED light emitting array is arranged on the light path system mounting base by the LED mounting hole.
Light path detecting unit of the present utility model is two groups, can receive the light signal of corresponding wavelength LED light emitting array; Each optical filter of organizing the light path detecting unit is Wavelength matched with corresponding LED light emitting array.
Photoelectric sensitive device of the present utility model is photoelectric cell.
The beneficial effects of the utility model:
The light path parameter of the utility model active light source is adjustable, by the emission angle that changes active light source or the method that increases and decreases the quantity of emission light belt, change in the situation that do not change measuring height the physical dimension of measuring light belt, adapt to the measurement of different scale canopy reflectance spectra, improved signal to noise ratio (S/N ratio), dirigibility and the adaptability of system.
Description of drawings
Fig. 1 is structural representation of the present utility model.
Fig. 2 is light path system mounting base front view of the present utility model
Fig. 3 is light path system mounting base rear view of the present utility model
Fig. 4 is LED installation positioner of the present utility model
Fig. 5 is light path system general assembly drawing of the present utility model
Wherein: 1, spectral detection light path mounting hole; 2, light belt shaping groove; 3, steady arm mounting groove; 4, LED installation positioner; 5, plano-convex lens; 6, cylindrical mirror; 7, cylindrical mirror erecting frame; 8, regulate pad; 9, light path system mounting base; 10, optical filter; 11, photoelectric sensitive device; 12, LED light emitting array.
Embodiment
Below in conjunction with accompanying drawing and enforcement, the utility model is further described.
(1) specific embodiments of light path system
light path system integral body by mounting base (as Fig. 2, 3), regulate pad (as Fig. 5), cylindrical mirror erecting frame (as Fig. 5), (optical device comprises LED light emitting array 12 for LED installation positioner (as Fig. 4) and optical device formation, cylindrical mirror, plano-convex lens, optical filter 10 and optical sensitive device), can embed in mounting base from the below after regulating the combination of pad and cylindrical mirror erecting frame, and fit together by bolt, the LED installation positioner can be arranged on LED array on mounting base, after installing, LED array aligns with light belt shaping groove, monnolithic case figure after installation as shown in Figure 5.
The active light source light path system of light path system comprises two waveband narrow-band LED display (centre wavelength gets respectively 730nm and 810nm is example), light belt shaping groove, cylindrical mirror erecting frame, adjusting pad and cylindrical mirror form (cylindrical mirror length 80mm, width 20mm, focal length 30mm), can be projected to rectangular measurement light belt.
The spectral detection light path system of light path system comprises the same detection light path of two nested structures (as Fig. 2,3), comprise circular flat convex lens (diameter 12.7mm on structure, focal length 15mm), optical filter 10 and photoelectric cell form, photronic size need to consider the light path system optical parametric, make photronic sensing range cover at least the irradiation area of whole active light source, the photronic sensitizing range that this measurement mechanism adopts is of a size of 20mm * 10mm.Two covers detect optical filter 10 centre wavelengths different (centre wavelength is respectively 810nm and 730nm) of light path, complete respectively the reflected light transmission collection of centre wavelength separately, two cover spectral detection light paths are positioned at the homonymy of bar shaped active light source, and be arranged symmetrically with respect to bar shaped active light source length direction mid point, light path plano-convex lens optical centre line is parallel with active light source strip light length direction.
(2) active light source light path parameter can be regulated embodiment
Mounting hole in the LED installation positioner is the inclined hole with certain inclination angle, the inclined hole inclination angle can change LED illuminating source length direction emission angle, cylindrical mirror erecting frame and the combination of adjusting pad can be regulated the emission angle of LED illuminating source Width, in the utility model, length direction emission angle range of adjustment is 25 °~40 °, 0 °~4.5 ° of Width emission angle range of adjustment, active light source totally comprises the identical light path system that is arranged in parallel of 3 line structures (as shown in Fig. 5 structure), and 3 road light sources can be lighted alone or in combination.
The utility model does not relate to partly all, and the prior art that maybe can adopt same as the prior art is realized.