Field of the Invention

The present invention relates to profile assessment for cereal grains. The invention will be exemplified in the specification particularly with reference to cereal grains such as wheat grains which generally are a variable overall size and have a complex detailed shape. Background to the Invention

There is a need to have an accurate, reliable and reproducible assessment methodology so that a consignment of grain can be sampled and an assessment for quality and physical characteristics can be made, particularly so that the grain can be bulk stored in an appropriate grade as well as ensuring payment to the grower is fair and appropriate.

A conventional approach to assessment of wheat comprises taking a half litre sample from a bulk supply and effecting a standardised screening operation using a standard sieve or screen which has an array of rectangular apertures of 2 mm width. The standard test comprises shaking the sample 40 times and determining the proportion of the grain which passes through the sieve. Generally wheat grains or kernels which pass through the sieve (because they have a minimum transverse dimension of under 2 mm) are less desirable to the purchasers due to milling difficulties. Accordingly standards are set so that the value of the grain in a consignment is assessed in relation to the proportion by mass that has a grain dimension greater than a specified standard dimension. For example, the specified current Australian standard dimension for wheat is 2 mm; minimum size.

It will be appreciated that assessments must be effected quickly before the discharge of bulk grain delivered from a grower at a receival station. In an attempt to facilitate accuracy and reproducibility, a machine was developed to automate the shaking process in order to minimise operator influence on the test.

Currently in Australia there is a difference of $25 per tonne in grower payments across the range of 0-10% screenings for a typical wheat grade e.g. with a protein content of 13%. The screenings are the percentage by mass as determined in the sample which passes through the 2 mm slotted screen as determined from a sample. This pricing differential reflects the purchaser's view that in this case wheat less than 2 mm size in its minimum transverse direction is considered unmillable.

There are concerns about the accuracy of the slotted screens as they wear by repeated use. Even a small average increase in the slot width would result in growers being unfairly penalised for higher levels of screenings than in fact exist in the sample.

There is also a need, when applying official standards, to provide traceability for measurement as well as accuracy and reproducibility. The currently used systems do not meet this requirement. Summary of the Invention

The present invention generally concerns assessment of a grain material by positioning the grain in an optical path, establishing an image representative of a shadow of interest of the grain and analysing the image to provide an assessment of the profile against an optically assessed element of known dimension.

Although other approaches within the scope of the invention are possible, a particular example applied to a cereal grain (such as wheat) is for a profile to be assessed in a plane parallel to the short axis of the wheat kernel so that there is visible the minimum distance across the kernel and this is a prime factor to be compared against a standard such as the present standard dimension of e.g. 2 mm. However, it will be appreciated that the present invention provides a technical platform for the development of more sophisticated standards, assessments and analysis.

The present invention manifests itself in method and apparatus aspects as well as computer software and business methodology specifically adapted to provide processing of data.

According to a first aspect of the present invention, there is provided a method of assessing a cereal grain in terms of a shadow dimension comprising positioning and supporting the grain in an optical path of a beam of light such that the minimum shadow dimension is discernable from a shadow profile viewed from an end view of the optical path, optically assessing the shadow profile to determine the minimum dimension across the shadow, and optically assessing a known reference dimension against which the shadow dimension is compared to assess the grain.

According to a second aspect of the present invention, there is provided an apparatus for assessing a cereal grain in terms of a shadow dimension comprising a support for positioning the grain in an optical path provided by the apparatus, means for illuminating the grain with a beam of light to produce a shadow profile of the grain, the apparatus further comprising a calibration element against which the supported grain is

adapted to be assessed, apparatus having optical assessment means for viewing the shadow profile of the grain in an opposite direction to the direction of transmittal of the light beam and for optically assessing the shadow profile, and for viewing the calibration element, and means for determining the minimum dimension of the grain shadow.

The apparatus may include the calibration element in the form of a scale optically assessed by the optical assessment means.

One important methodology in applying the invention is to take a small bulk sample and to manipulate the sample into a sequential supply of individual grains for individual assessment. The grains are supplied to a receiving station in the optical path wherein the grain is optically assessed, the desired profile monitored and the profile assessed against a standard to provide output information. A large number of grains from the sample are processed and an output assessment of the sample against the standard is given. One embodiment utilises a V-shaped support into which a grain falls and is oriented parallel to a path of optical illumination extending along the V-shaped block such that the profile viewed is an end view, hi the case of wheat, the crease in the grain profile will be visible as well as the transverse view which includes the minimum shadow dimension and which would be the factor controlling whether the grain passes through a standard sieve or screen. A camera system captures the image which can then be analysed in a microprocessor and assessment against standards achieved using stored algorithms. A parallel light source from a light emitting diode (LED) and lens can be used with the V-block so that the grain profile is readily and distinctly displayed. A more sophisticated light projection system may also be used. It will be appreciated that with suitable algorithms for profile analysis as well as data storage and reporting, accurate records of samples can readily be retained in equipment which can be provided economically in a robust and useful form for operation by essentially unskilled operators at grain receival stations. By using a suitably calibrated and certified apparatus, grain growers and purchasers should be able to have confidence in assessments which are performed rapidly, i.e. within a few minutes. Indeed use of embodiments of the invention facilitates the assessment of a multiplicity of small samples from different portions of a truckload of grain so that a fair and reproducible grading system can be implemented.

Another embodiment is to a data processing system and method wherein profile analysis for grain is effected from image data supplied from a suitable system in any form described herein. The system may be remote from the location where the grain is assessed. The system could be a website based server. Summary of the Representations

For illustrative purposes embodiments of the invention and an example will now be given with reference to the accompanying representations of which:-

Fig 1 is a representative representation of a wheat kernel profile located and profiled in an embodiment in a particular orientation; Fig 2 is a schematic general arrangement representation of an embodiment;

Fig 3 is a view of a distance calibration scale in the same filed of view as the supporting V-block for grain kernels for use in the embodiment of Figs 1 and 2; and

Fig 4 is a view of another wheat kernel, in a different orientation than that shown in Fig 1, and illustrating dimensions which are applicable to a mathematical analysis of the profile which has been stored. Detailed description of the Embodiment

Fig 1 shows a wheat kernel 10 supported in the V surface 12 of a V-block 14, the kernel essentially being in end view with its major direction of elongation being at right angles to the plane of the representation. The wheat kernel 10 has an irregular profile 16 characterised by a typical crease 18.

Referring now to the general arrangement of Fig 2, the overall apparatus is schematically represented and comprises a monitoring and analysis system having an optical path 20 along which are aligned a light source such as a light emitting diode (LED) 22, convex lens 24 for producing a parallel beam of red light 26, the V-block 14 for supporting the wheat kernel 10, a telescope 28, an industrial grade digital camera 30, a computer 32 for analysing images from the camera and a monitor 34 for displaying the image and, in the case of a wheat kernel, for validating appropriate positioning of the kernel in the V-block, i.e. with the crease in the side of the wheat kernel visible. The system is designed to handle a large number of samples individually in rapid succession and a feed system (not shown) is provided for sequentially supplying the individual kernels using a vibratory or pneumatic supply arrangement which causes the kernel to self orient on the V-block. After measurement, the kernel is withdrawn and the next kernel is supplied.

Fig 3 shows the option of incorporating, in association with the V-block 14, a conventional standard scale 36. However, accurate knowledge of the dimensions of the V-groove surface can be relied upon for calibration purposes.

The wheat kernel profile as shown in detail in Fig 1 can be used for automated detection of the grain boundary and also to detect the crease of the grain to validate appropriate orientation of the wheat grain in this case. Image analysis algorithms are used in the computer 32 to effect this task and are discussed in more detail below. The principle used is that once the grain boundary has been detected, the relevant thickness, i.e. the dimension across the grain, can be calculated by a mathematical procedure that determines the minimum cross sectional dimension of the grain shadow. Fig 4 illustrates this approach in more detail by developing minimum boundary lines 37 and 38 defining the grain thickness whereas maximum boundary lines 39 and 40 define the grain width.

The mathematical analysis is based on a multiplicity of readings usually made stepwise by rotating a pair of parallel view lines aligned to be in contact at opposed sides of the shadow. The minimum distance is thus determined.

A consequence of the measurement is that a record can be kept on the computer and analysis of numerous grains quickly determined to assess the proportion of the grain exceeding a minimum standard and the proportion falling below the standard. By including data related to individual kernel weights, which can be measured in the system that feeds individual grains, a computation can readily be made to produce a result related to the present standard, namely the proportion of grain by mass in a sample which passes through a conventional two millimetre screen.

It will be appreciated that a more sophisticated analysis can readily be performed using the present profiles if such deductions are considered worthwhile for any purpose.

In this specification the word "comprising" is used in a non-exhaustive sense in that other features may be included.