WO2008126013A2

WO2008126013A2 - Method to decrease separation losses at the harvest of grains and advance speed regulating device of a harvester to decrease separation losses

Info

Publication number: WO2008126013A2
Application number: PCT/IB2008/051342
Authority: WO
Inventors: Emanuel SLAWIÑSKI; Vicente Antonio Mut
Original assignee: Consejo Nacional De Investigaciones Científicas Y Técnicas (Conicet); Inis Biotech Llc
Priority date: 2007-04-11
Filing date: 2008-04-09
Publication date: 2008-10-23
Also published as: WO2008126013A3; AR060425A1

Abstract

A method and device to decrease separation losses in a harvester, wherein grain separation losses or harvest yield are detected and controlled changes are introduced to the advance speed of the harvester in a way that can be previously defined by the producer without overriding the contribution of the operator driving the machine. Instead of connecting the accelerator cable (37) to the accelerator pedal (25), it is physically connected to an electrical motor (31). On the other hand, the pedal is connected to a positioning sensor (29) that is read by a processor (43), which delivers a control signal to the electric motor to control the fuel passage to optimize the harvester advance speed (11), seeking for the best balance between separation losses and harvest time.

Description

METHOD TO DECREASE SEPARATION LOSSES AT THE HARVEST OF GRAINS AND ADVANCE SPEED REGULATING DEVICE OF A HARVESTER TO DECREASE SEPARATION LOSSES

Field of the Invention:

This invention refers to a method and device to optimize soy or other grain harvest by regulating the advance speed of the harvester to minimize grain losses. This invention is applicable to minimization of separation losses, which magnitude is correlated to the advance speed of a harvester.

Production of grains such as soy, corn, sunflower and wheat has considerably increased in the recent years in countries such as Argentina, due to diverse factors as the genetic evolution of crops, implementation of direct seeding that leads to a more efficient usage of water, reduction and practically elimination if weeds such as Sorghum halepense, Cynodon dactilon, Cyperus rotundus, malva, etc., obtaining genetic varieties tolerant to insects and diseases, and improvements in the chemical control, balanced fertilization in some crops and seeding, spraying and harvesting machinery. Harvest yield can be increased further by improving harvester operation, for example increasing the advance speed of the harvesters.

However, the higher is the advance speed the higher may be the losses. Harvest losses may be classified in soy harvest in (see, "Harvest losses. Evaluation and tolerances in soy, corn, sunflower and wheat", Mario Bragachini, Axel von Martin and Andres Mendez. Technical report, agriculture and precision project, INTA Manfredi, http : //www. agrilturadeprecision . org/siembCoseAlma/Perdida sCosecha .htm) :

- Pre-harvest losses (15% of total losses), produced by loose beans and plants knocked over that the harvester header is not able to gather;

- Harvester losses (85% of the total losses), due to header losses that occur by shatter loss, plants knocked over, cut height, cutterbar and loose stalks, and separation harvester losses.

Figure 1 shows the different types of harvester 11 losses. Seventy percent of the soy harvester losses are caused by the header 13, of which 50% are caused by the movement and friction imposed by the cutterbar to the plants 17, which main factors are an excess of the advance speed of the harvester 11 and deficiencies such as worn out knives 15. The remaining 30% corresponds to separation losses. As also shown in Figure 1, separation losses are also produced in different ways, such as grain loss by the cylinder 19 (8%), screen (21%) and straw- blower 23 (11%) .

Blocking or overcharge of cylinder 19 is caused by a non-uniform density of the crop 17, soil humidity and any other cause that leads to an overcharge such as an increase of the feeding ratio. In these cases, the overcharge increases the level of separation losses and the situation is corrected by decreasing the advance speed, which decreases the feeding ratio (in tons/hr) and therefore cylinder 19 overcharge.

The straw-blower 23 overcharge is caused by the grain not passing by the screen and has de same causes. However, in this case it is very important to consider that soy is hard to screen when straw is very humid or green by lack of ripening at the time of harvesting. Under this circumstance, the straw-blower 23 does not stir enough, forming a non-permeable layer for the grains, increasing separation losses of the harvester. In these cases, it is desirable also to lower the feeding ratio of the harvester 11 decreasing the advance speed.

These separation losses are shown in figure 2 wherein it is also evidence their correlation with the feeding ratio of a harvester. The wider is the cylinder and the more powerful is the harvester engine, the higher will be the amount of material (grain, straw, chaff and weeds) the machine is able to process by unit of time, expressed in tons/hr. This value is called total feeding index and for a given cut wide, is proportional to the advance speed of the harvester 11.

The present invention is to regulate the instant speed of the harvester 11 to optimize two divergent parameters from certain advance speed, i.e. the gathering speed measured in amount of grains (quintals, tons, etc.) by unit of time (hour, day, etc.) and separation losses, quantified percentage of lost harvested grain. State of the Art and Problems to be solved

There are different patent references related to harvester losses though none of them refers specifically to regulate the advance speed as a function of the grain stream passing by the harvester at all times. Among those references US Patent 6.592.453 can be illustratively mentioned, which attempts to reduce losses due to soil drops, by measuring the soil slope and, according to that, decreasing the harvester speed to reduce this kind of losses. Summary of the Invention The present invention makes controlled and limited changes of speed to the command generated by the used, so that to regulate adequately the relation between separation losses And harvest time, defined by the producer, without affecting the general decisions made by the operator .

The invention also recognized that capabilities and expertise of the operator must be considered to obtain good results in the grain harvest. Though technological modernization is progressively increasing, improving harvester efficiencies, for example advances in header development, a complete automation of agriculture is unlikely. Therefore, it is also an object of the invention not to override the human operator nor waste his expertise by replacing the used by an automatic control, but to incorporate technology that improves harvester efficiency, benefiting from capabilities of operators to increase the harvest yield.

The method and device of the invention to harvest grains with lower separation losses in harvesters attains these and other objects and benefits by incorporating monitoring sensors of separation losses and an electronic accelerator to generate information used to correct the advance speed of the harvester, allowing to increase or decrease the advance speed to avoid overcharges and better take advantage of the harvest capability (in tons/hr). The electronic accelerator is a conventional accelerator pedal assembly plus a positioning sensor that generates an electrical signal in response to the accelerator angle determined by the operator . A monitor of losses or yield is connected to a processor to analyze the loss level. Instead of being connected to the accelerator pedal, the steel wire - or other mechanical or electromechanical element - conventionally connected to the fuel dosing means of the driving engine of the conventional harvester is physically connected to en electrical engine also linked to the angular positioning sensor, which feedbacks a positioning signal from the engine to the processor. The processor delivers a control signal through an electronic power amplifier to the electric engine to vary the fuel passage to the main driving engine of the harvester.

The proposed device decreases the amount of losses produced in harvesting soy, according to the point of operation established by the producer, cooperating with the used in controlling the advance speed of the harvester by using loss data and the acceleration command generated by the operator, without interfering with the decisions and general driving of the operator. The loss level is measured with a loss monitor adequately regulated, that updates the operator about changes related to loss level, indicating him to increase or decrease the feeding ratio (that is to say the advance speed) in case of a decrease or increase, respectively, of the loss level.

In the practice, the operator drives the harvester generally at a constant speed, which will be maximum speed if the data signal indicates low separation cola or medium speed according to his expertise when the loss level is high. Brief Description of the Drawings

These and other characteristics and features of the object of this invention and the way the invention can be developed and practice may be better understood by the following detailed description illustrated in the attached drawings, which are only exemplary and non limiting; however other variations, modifications, adaptations and/or additions may be eventually introduced without departing from the nature and spirit of the invention. In the drawings:

Figure 1 is a schematic view of a harvester facing a crop wherein different types of grain losses and relative ratios of the same are represented.

Figure 2 is a graph of the different separation loss levels as a function of the advance speed of the harvester .

Figure 3 is a block diagram of a device to decrease separation losses in a soy harvester according to this invention, which hardware replaces de operation of a conventional accelerator, and includes all the additional components that connect the operator with the proposed compensator, as illustrated.

Figure 4 is a hardware scheme of a preferred circuit for the device of figure 3.

Preferred Embodiment of the Invention

Figure 3 shows the replacement of a conventional accelerator pedal 25 with an electronic accelerator 27 comprised by the accelerator pedal 25 that incorporates a positioning sensor, for example a potentiometer 29 or an absolute digital encoder, and a dc electric motor 31, for example a motoreducer Ignis model MR8-78, connected to an angular position sensor, for example a potentiometer 33. The electric motor regulates the fuel passage to the internal combustion engine of the harvester 11 by changing the position of the acceleration valve 35. That is, the cable 37 position (or any other mechanical or electromechanical element that determines the position of the acceleration valve 35) that conventionally would have been directly determined by a conventional pedal 25, is determined now by the electric motor 31 controlled by the voltage V applied by a power amplifier 39. The amplifier may be comprised by an integrated circuit L293B or LMD18200 containing a bridge configuration amplifier.

Voltage V that determines the position of cable 37 is calculated by software components 41 and 43 programmed on a microprocessor 43 represented in figure 4, which CPU 47 is comprised by a PIC model 18F2480 or 18F258. As optional accessories a keyboard 49, a LCD screen 51, form example WM-C1602M-lYNNb manufactured by Wintec Corp. and an EEPROM serial memory can be included, connected to the microprocessor 45 to allow a quick calibration of the device and view and store the system status.

With a button or switch, 55 connected to the microprocessor 45 the device of the invention is turned on and off. The power for the electronics is supplied from the power system (batteries) 57 of the harvester 11, using integrated circuits and standard regulating components 59 (in figure 4 only the CPU power supply has been schematized) .

The microprocessor 45 receives as inputs the values of separation losses P (k) , the angular position θ_H(k) of the electronic accelerator 27, the advance speed v of the harvester 11 and the angular position θ_m(k) of the electrical motor 31. This last value is provided by an angular positioning sensor 33, form example a potentiometer or an absolute digital encoder, coupled to the electric motor shaft 31, while said separation loss data can be provided by a loss or yield monitor 61 through a CAN type transceiver interface device 63, for example an integrated circuit MCP 2551, connected to a CAN bus 65.

The loss monitor 61 delivers a signal to the microprocessor 45 proportional to the number of grains lost by separating, that is to say falling through the screen 21 and the straw-blower 23, indicating the level of losses by unit of time or area. The company Sensor from the city of Torotas in the province of Santa Fe provides parts of this kind, which are technologically competitive. The yield monitor is a more complex device, compatible with GPS satellite technology systems to provide crop maps (speed, density of seeding and distribution of seeds) and make calculations of yield as a function of the grain flow by unit of time, grain humidity, and advance speed v of the harvester 11 and the cut width of the header 13. The model "Insight" manufactured by the German company AG Leader is an example of a state of the art yield monitor.

Voltage V applied to the driving motor 31 is governed by a positioning control PID link 41 implemented through a software component programmed on the microprocessor 45. The positioning control component 41 receives the angular position feedback θ_m from the electric motor 31, coming from the position sensor 33, and a position reference θ calculated by a loss compensating component 43 also programmed on the microprocessor 45 from the separation loss level entries P(k) supplied by monitor 61, actual advance speed v(k) of the harvester supplied by sensor 67, for example an absolute digital encoder mechanically coupled to a wheel 69 or shaft of the harvester 11, and the angular position

Θ_H of the electronic accelerator 27, as follows: θ = Θ_H + Δθ, wherein Δθ is the adjustment calculated by the electronic compensator 45 and applied over reference Θ_H generated by the operator through the electronic accelerator pedal 27. Reference value Θ_H ranges from zero for the accelerator 35 not pressed and θ_ma_x for the accelerator 25 fully pressed.

The angular reference adjustment Δθ for a discrete time k is calculated by the loss compensator 43 as follows :

Δθ (k) = K θπώx ( e ^{λ p (k)} - ΘH ) , s i Θ_H > θ_min

Δθ (k) = 0 , s i Θ_H ≤ θ_min wherein 0 < K < 1 represents the compensator gain upon variations of the loss level, wherein 0 < θ_mi_n « θmax, P(k) > 0 is the separation loss level by actual area unit and y 0 < λ < X_m3x defines the desired operation point by the producer relating separation losses P(k) to the advance speed v(k) of the harvester 11.

The device described decreases, during the harvest, the separation loss level compared to losses that would be experienced with the sole presence of the speed manual control, without affecting the general driving decisions made by the operator. In this way, the present invention connects two main objects for a harvest: producer and operator. The parameter λ of the compensator establishes the desired operation point, considering in this case two fundamental characteristics for a harvest, which are opposed to each other and refer to admissible losses and harvest time (inversely proportional to the harvester advance speed) . The operation point is established by the producer. Table 1 shows the operation of the compensator according to different values of λ escalated with its maximum value .

Table I

Moreover, this invention takes into consideration the expertise and capabilities of the operator by parameter K. Table II shows the compensator operation according to different values of K.

TABLE II

Button or switch 55 makes the program in the microprocessor 45 set the value of K to zero. Then, if K = O, θ = Θ_H so that position reference θ for the electric motor 31 is equal to position Θ_H of the electronic accelerator 27.

Obviously, different modifications can be made to the invention without departing from its spirit and scope. It is to be noted that despite of ore proposal is related to soy harvesting, it is applicable to other types of grains (for example: wheat, corn and sunflower), adjusting parameters K y λ considering the type of grain, expertise and capabilities of the operator and the producer decision.

Claims

What is claimed is :

1. A method to decrease separation losses in grain harvest wherein an operator manually generates an advance speed signal, characterized by comprising the steps of: monitoring the separation grain losses or the harvest yield and generating a signal representative of said losses, combining said signal representative of losses with said advance speed signal manually generated to generate a compensating signal, and applying said compensating signal to determine said advance speed during the harvest.

2. A method according to claim 1, characterized in that a harvest actual advance speed signal is also feedback that is also combined with said signal representative of losses and said manually generated advance speed signal to produce said compensating signal.

3. A method according to claim 1 or 2, characterized in that said manually generated advance speed signal is also present as a value substantially different from the zero advance speed in said compensating signal during the harvest (so that the operator is still able to decide the advance speed) .

4. A method according to any of the preceding claims, characterized in that said signal representative of losses generated by monitoring modifies the advance speed signal limitedly.

5. A method according to any of the preceding claims, characterized in that said step of generating by monitoring the signal representative of losses comprises detecting the flow of grains harvested by unit of time and generating a signal proportional to said flow as said signal representative of losses.

6. A method according to any of the preceding claims, characterized in that in said step of combining signals, the signal representative of losses is affected by a gain parameter that varies according to the expertise or capabilities of the harvester operator and by a parameter that varies according to a priority classification of the desired harvest speed over the acceptable loss level.

7. A method according to any of the preceding claims, characterized in that in said step of combining signals, the manually generated advance speed signal is adjusted to a gain parameter that varies according to the expertise and capabilities of the harvester operator.

8. A method according to claims 6 and 7, characterized in that signal representative of losses is processed according to a decreasing function that represents the operator behavior desired by the producer to obtain a signal representative of speed desired by the producer, and this signal is adjustedly combined with said manually generated advance speed signal.

9. A device to regulate the advance speed of a harvester to decrease its separation losses, the harvester comprises a main driving engine which speed is commanded by a driving means of the same through a manual accelerator; characterized by further comprising a separation loss monitor connected to the input of a processor unit capable of generating a compensating signal on its output, being said output of the processing unit connected to said driving means of the main driving engine so that it is capable of modifying the speed commanded by said manual accelerator .

10. A regulating device according to claim 9, characterized in that said manual accelerator comprises the original accelerator linked to a positioning sensor connected to other input of said processing unit and said driving means of the main engine us commanded by an electrical motor connected to said outlet of the processing unit, being also an angular positioning sensor coupled to said electric motor and connected to another input of said processing unit, including said processing unit calculation components capable of combining said inputs in a predetermined manner to generate an output signal capable of positioning said electric motor.

11. A regulating device according to claim 10, characterized in that said driving means of the main engine comprises a steel wire connected between the output shaft of said electric motor and a fuel dosing means of said main driving engine of the harvester.

12. A regulating device according to claim 10 or 11, characterized in that said angular positioning sensor comprises a digital encoder or potentiometer connected to the shaft of said electric motor.

13. A regulating device according to any of the claims 9 to 12, characterized in that said separation loss monitor comprises a flow or passage sensor installed at least in one of the following: the cylinder, the screen, and the straw-blower of the harvester.

14. A regulating device according to any of the claims 9 to 12, characterized in that said loss monitor comprises a grain flow or passage sensor which measurement is correlated to the advance speed.

15. A regulating device according to any of the claims 9 to 12, characterized in that said separation loss monitor comprises a yield monitor.