WO2005099429A1

WO2005099429A1 - Automatic rotary electro-pneumatic digger with tractor self-navigation

Info

Publication number: WO2005099429A1
Application number: PCT/YU2005/000011
Authority: WO
Inventors: Radivoj Matic
Original assignee: Radivoj Matic
Priority date: 2004-04-15
Filing date: 2005-04-14
Publication date: 2005-10-27

Abstract

The construction design of the excavator consists of the following: on the support beam (1) and the support (15), a reducer (2) is mounted together with compressor (3), drive wheels (5), then a transmission shaft (27) with transmission belts (29) is mounted and connected through the belt (30) with already prepared units (6) for excavation with horizontal shafts - for digging up of plants which have a stem - or units (7) for excavation with vertical rotary shafts - for digging up of plants without a stem. The control over the automatic electro-pneumatic system for digging up is performed by means of a mechanism (8) for the maintaining of parallel position, a unit (10) for detection of a plant and programmable logical controller PLC (11) with a program for tractor self control.

Description

AUTOMATIC ROTARY ELECTRO-PNEUMATIC DIGGER WITH TRACTOR SELF-NAVIGATION

FIELD OF TECHNOLOGY OF THE INVENTION: The invention relates to the field of agricultural engineering, more precisely, to the category of agricultural machinery for digging and cultivation of soil, i.e. to digging machines. It is classified according to the international patent classification as MKP (7): A01 B 77/00. ENGINEERING PROBLEM: How to find engineering solution for the construction of automatic rotary electro- pneumatic digger suitable for removing of weeds both between rows and inside rows, between sown plants, with application of electronics and pneumatics, which would provide a reliable and safe operation without damage to the plant or the plant's root, easy operation and simple connection to the tractor unit, low energy consumption, inexpensive manufacturing and easy maintenance. CURRENTLY AVAILABLE TECHNOLOGY: Currently, the removal of weeds is performed by means of: chemicals, mechanical weed cutting machine, or manually, with a hoe. However, all these methods have many disadvantages. Application of chemicals - herbicides, is not good because it pollutes the ground, fruits and, by evaporation, even wider environment. The weed cutting machine requires the tractor unit and additionally - manual work, because the cutting operation is performed only between rows, however, the removal of weeds within a row is performed manually, with a hoe, which makes the whole procedure very slow and expensive. The manual removal of weeds with a hoe is very slow, requires hard work of people and is still expensive.

EXPLANATION OF THE SUBSTANCE OF THE INVENTION: Electro-pneumatic digger with tractor self-navigation consists of the main beam on which are mounted following components: supports, drive wheels, air compressor, supports for connection of the digger with tractor unit and digging unit with horizontal rotary shafts (for earthing of plants with stems), or digging with vertical rotary shafts (for earthing of plants without stems). Automatic system for earthing of plants is controlled through the mechanism for maintenance of parallel position, plant detection unit and Programmable Logic Controller, PLC with software for tractor self-navigation. The design of the digger consists of the main beam and supports on which the following components are mounted: a reducer, air compressor, drive wheels, transmission shaft with pulleys which are, through a belt, connected with digging units with either horizontal or vertical shafts. The digger operates in the following manner: first, supports are connected to the tractor unit, and the Cardan shaft is connected to the outlet shaft of the tractor unit, then the air is connected, and finally, PLC is activated through the battery and voltage converter. The start-up of the tractor and digger, to begin the digging procedure, is performed through drive wheels, chains, chain-pulleys, pulleys and belts, carrying transmission up to the digging units, controlled by PLC, which is programmed to operate, through electro-magnetic valves and pneumatic cylinders, according to specified "stroke" that corresponds to selected spacing between seeds during the sowing procedure, i.e. the spacing between plants in a row. SHORT DESCRIPTION OF FIGURES: Figure 1 - Schematic figure of the digger with horizontal shafts rotary retractable digging units (for earthing of plants with a stem), in a rear view. Figure 2 - Side view, projection II of Fig. 1 - transmission of rotary movement from tractor outlet shaft up to the rotary shaft with blades (rotary retractable digging unit), location of PLC electronics cabinet and location of pneumatic valves cabinet on the tractor. Figure 3 - Schematic figure of the rotary shaft in partial section, showing the design of two-way pneumatic cylinder with compressed air supply. Figure 4 - Schematic rear view of the digger with vertical shafts (for plants without a stem) with rotary movement of the shafts and connection with pneumatic cylinders. Figure 5 - Projection "4" in the view from above, showing pneumatic cylinders, vertical shafts and their positions and movements during the operation. Figure 6 - Side view of the mechanism for the maintenance of parallel position (of tractor wheels and attachment units), which is manually operated through the tractor steering wheel. Figure 7 - View from above of the Fig. 6, showing the toothed connection between the tractor steering wheel and the mechanism for the maintenance of parallel position, in its "zero-correct" position, maintained with supports with springs. Figure 8 - Three systems of automatic electro-pneumatic control (based on PLC) I - represents the monitoring of movement direction with light and sound signals, II - the system shows the plant detection unit III - tractor self-navigation along the row with sprouted plants Schematic presentation of the connection from the battery, voltage converter, PLC, compressor, cam disc, pneumatic cylinders, induction sensors and electro-pneumatic valves.

Figure 9 - Section view of plant detection mechanism - left - with pneumatic one-sided performance cylinders (when piston rod is outside, the mechanism performs detection of plants, which is not the case when it is in extracted position in the cylinder and protected with the housing), rotary, laminated - spiral spring and induction switch activating plate.

Figure 10 -Section view of the plant detection mechanism - right - during the plant detection operation with the mounted support on the pneumatic cylinder.

Figure 11 - View from above of Fig. "9" showing position of the plate and induction switch.

Figure 12 - View from above of Fig. "10" showing the approach to the plant, piston rod swivelling and its retraction into the cylinder. In case there is no plant, the swivelling is performed through the piston rod of the pneumatic cylinder driven by water with a throttle. Position of the plate under the induction switch indicates that electric signal is obtained which interrupts the operation and starts the operation of a new stroke (from plant to plant).

Figure 13 - Schematic figure of the tractor and digger and their connection through the support, the mechanism for maintaining of parallel position located in front of the tractor steering wheel, mechanism for plant detection with wire brush (in front of the tractor and on the digger), as well as the position of electric distribution cabinet with PLC and cabinet with electro-pneumatic valves.

Figure 14 - Schematic figure of the tractor and digger with plant detection mechanisms, their height position in relation to the plant, as well as method of lifting and lowering of mechanisms in front of the tractor through the pneumatic cylinder with pass- through piston rod. Figure 15 - Plant detection mechanism (in front of the tractor). Lifting and lowering is manually operated through pneumatic shaft (from the tractor cabin) and a two-way pneumatic cylinder with a pass- through piston rod. Figure 16 - Manually operated pneumatic valve, through which the foot throttle control from the tractor cabin is performed by means of the one-way operation cylinder piston rod of certain length.

DETAILED DESCRIPTION OF THE INVENTION: Automatic rotary electro-pneumatic digger with tractor self-navigation (hereinafter referred to as "digger") is shown in Figures 1 through 16. It is a new engineering solution in the field of agricultural machines for digging and cultivation of soil. It provides: removal of weeds both between rows with sown plants and within a row, between plants, without damaging plant or plant's root, reliable and safe operation, easy and simple connection to the tractor unit, low minimal energy consumption, inexpensive manufacturing, easy maintenance, etc. The digger is intended for earthing - removal of weeds in wide-row sown crops, both between rows and within a raw - between plants. The digger consists of: main beam 1, reducer 2, compressor 3, supports 4, drive wheels 5, digging unit 6 with horizontal rotary shafts (hereinafter referred to as "rotary unit") - for plants with a stem, digging unit 7 with vertical rotary shafts - for plants without stem, mechanism 8 for the maintenance of parallel position, tractor steering wheel manual control with electronic (sound and light) monitoring of moving direction 9, plant detection unit 10 and Programmable Logic Controller - PLC with tractor self- navigation software. The digger is designed as follows: on the main beam 1, supports 12, 13, 14 are mounted with a fixed joint and supports 15 and 16 with a detachable joint, on which a reducer 2 is mounted with inlet Cardan shaft 17 with a pulley 18. The pulley 18 is connected with belt 19 with the pulley 20 which is on the compressor 3, and on supports 14 are fixed supports 4. Drive wheels 5 with a cam disc 22 on their axle 21 are connected to the main beam 1. On the reducer 2 outlet shaft 23, a chain-pulley 24 is mounted which is connected through the chain 25 to the group of pulleys 26 on the transmission shaft 27, which is, through a housing with bearings 28, connected to the support 15. On the transmission shaft 27, pulleys 29 are mounted, which are through a belt 30 and belt fastener 31, connected to pulleys 32 on digging unit 6 with horizontal shafts. Levers 34, wheel 35, spring support 36, shaft support 37 and digging unit 6 with horizontal shafts or digging unit 7 with vertical shafts are connected though a hinged joint to the_support 33 which is connected to the main beam 1 with a fixed joint. Supports of the plant detection mechanism 38, wire brush consisting of "S" springs 39, leaves protectors - front 40, plants 41, hoe 42, support 43 and rotary unit 6 protector 44 are connected to the shaft 37 supports, through a detachable joint. Supports 45, carrying the housings with bearings 46 through which an axle with a gear 48 and leaves protector - rear 49 and plant 50, is passing 47, are connected to supports 15 with a detachable joint. On the support-carrier 51, a rotary pneumatic two-way cylinder is mounted, which has on its outlet shaft 53 a special bearing 54 with a gear 55 through which the gear 48 and axle 47 receive the rotary movement. Digging unit 6 with horizontal shafts is composed of a support 56 and horizontal rotary unit 57. Horizontal rotary unit 57 is composed of a housing with bearings 58 through which a Cardan shaft with inside channels 59 is passing, on which are mounted a support with blades 60 and a pulley 32 through which the horizontal rotary unit 57 receives the rotary movement. Cardan shaft with outside channels 61 (hereinafter referred to as "rod") is inserted through a sliding joint into Cardan shaft with inside channels 59. The rod 61 passes through cylinder 62 which is divided by a sealed ring 63 into two parts. Compressed air supply hoses with connections 64 and 65 are mounted on the first part of cylinder while the second part of the cylinder serves for rod movement 61 within piston 66 (rod movement 61 from connection 64 to connection 65). The piston 66 is socket shaped with flanges (design adjusted to its function). On the narrower flange there are sealing rings 67. On the other flange, through the bearing 68 (the rod 61 connected with the piston 66), which at the same time maintains centricity and sliding joint between rod 61 and shaft with inside longitudinal channels 59. Sealing ring 69 and sealing ring 70 of piston 66 are moving axially over the inside surface of cylinder 62 and outside diameter of the socket 71, which with threaded connection, closes one side of cylinder 62. Bearing support 72 closes with threaded connection (along the outside ring) the outlet side of cylinder 62, and into the bearing 73, a graduated socket 74 with longitudinal channels along outside and inside diameter is fitted and fixed. Rod 61 passes through inside diameter of the graduated socket 74. Support with blades 75 is fixed to the outside diameter with bolts. At the end of the rod 61, there is the outside "satellite" blade 76, which in addition to rotary movement performs also axial movement, which was the aim of the design. Rod 61 is between support with blades 75 and outside "satellite" blade 76 protected with conical corrugated rubber 77. Blades supports 60 and 75 are fitted on both sides with sealing rings 78. Rotary horizontal unit 57 is fixed with bolts 79 to two semi-cylindrical (from support 56) fixed clamping plates 80 and detachable clamping plates 81. Digging unit 7 is composed of "vertical shafts" and is connected to the support 37 through support 43. With support 43 there is the support 82 with housing and bearing 83 and a sleeve 84 and housing with bearing 85 and sleeve 86. Conical gear 87 and pulley 88 are mounted to the sleeve 84, and conical gear 89 and two-groove pulley 90 for belt 91 is mounted onto the sleeve 86. Support 43 connects supports with plates 93 on which there are two-way pneumatic cylinders 94. On the fixed support 95, there is a housing with bearing 96 and sleeve 97 on which there is a two-groove pulley 98 for belt 91. The fixed support 95 is connected with a hinge 99 to the movable support 100, on which there is a housing with bearings 101 (connected to the two-way cylinder rod 94 through which vertical shaft is passing 102 on which there is a pulley 103 connected through a belt 104 and a pulley with two grooves 98. On the lower part of the vertical shaft 102 there are rotary blades 105 which perform the earthing function between plants 106 and 107. In front of rotary blades 105 on the support 43 there is a middle hoe 108 and side hoes 109. In order to achieve synchronized action of the tractor unit and the digger during their operation, and in order to maintain precise direction of movement by means of tractor steering wheel manual control - mechanism 8 is installed for the maintenance of parallel position of tractor wheels and the wheels of the agricultural attachment unit. The mechanism 8 for the maintenance of parallel position consists of toothed segment 111 fixed to the tractor steering wheel. Onto the support 112, which is connected with a fixed joint to the tractor unit, a plate 113 is mounted (it can be lifted and lowered by means of the rotary element 114 and hinged support 115) on which there is (engine support 116 - used only with tractor self- navigation) a housing with bearing 117 through which shaft 118 is passing onto which the support with a plate 119 is mounted, with a gear 120 on which levers 121 are fixed (hereinafter referred to as gear with levers 122) whose position is maintained with supports with pressure springs 123 which serve to maintain the parallel function with its force. Swivelling of the steering wheel i.e. the gear with lever 122 is limited with position arresters 124. When the tractor steering wheel manual control, through mechanism 8 for maintenance of parallel position, is upgraded with electronic control based on the Programmable Logic Controller (PLC) 11, the following is achieved: - Tractor steering wheel manual control with electronic (sound and light) monitoring of the movement direction 9. PLC 11 is positioned in an electric distribution cabinet 126, which is connected to the tractor battery 12 VDC - through the voltage converter 127 24 VDC. The start-up of the system is performed from the control panel 128 through a cam switch 129. On the mechanism for maintenance of parallel position 8, induction sensors 131 are fitted, and in case the tractor steering wheel, i.e. the support with a plate 119 is swivelled to the left or to the right, PLC 11 will receive information and a signal light 130 will appear (left, right), as well as the sound signal - a horn 132, warning the operator of the incorrect swivelling of the steering wheel. Plant detection unit 10. For the performance of digging procedure, from the cam disc 22 signals are obtained through induction sensor 133 (the path run) and induction sensors 134 and 135 which are fitted in the plant detection mechanism, both left 136 and right 137, which consists of a support 138 on which there is a housing 170 with bearings 139, 140, sleeves 141, 142, between which there is a rotary element 169 with possibility of swivelling of pneumatic one-way cylinder 143, and on the upper part of the sleeve 142, which is in box 144, there is a laminated spiral spring 145, which is with one part connected to the sleeve 142, and with the other to the inside surface of the box cover 144 and it returns the swivel cylinder 143 into its original position. On the front side of the sleeve 142 there is a plate 146, and through the box cover 144 induction sensor is fixed 134. On the right plant detection mechanism 137, i.e. on the pneumatic cylinder 143, support 147 is fixed swivelled by pneumatic cylinder 148 which on its air supply duct has a throttle 149. Signals from sensors 133, 134 and 135 are received in PLC 11 and, turning on/off of performing elements is made through counters B 1 150 B2 151 B3 152 by means of relay 153, electro-magnetic valves 154, 155 and 156, through which air from compressor 3 is passing and is distributed through pneumatic plastic hoses 172 toward all air consumers in the machine. Electro-magnetic valves 154, 155, 156 are positioned in cabinet 171, which is connected to electric distribution cabinet 126 (with PLC 11 inside) and are fitted in a plastic pocket in the tractor cabin in which way they are protected from shaking and dust. From the control panel 128, through cam switch (selector) 129, light signals are activated 130 indicating the operation mode of each induction sensor 131, 133, 134 or 135.

- Programmable Logic Controller (PLC) with self-navigation software:

The system consists of manual control of the steering wheel with electronic (sound and light) monitoring of the movement direction 9, where the self- navigation regulation system has the function to correct the movement direction by means of PLC 11, based on information received from induction switches 134 and 135 from the digger, which are positioned in the plant detection mechanism 136, 137 (in front of the tractor unit). It enables the tractor unit to move along the defined path, i. e. the row with sprouted plants. The wire brush 39 is fitted in front of the plant detection mechanism. In case of the tractor unit deflection from the defined path, PLC 11 will switch on, through the contact device 157, the collector motor 158, which moves the steering wheel to the left or to the right, until the rear path is restored. In case of navigation irregularity, the light signal 130 and sound signal 132 are activated, and if the intense signals are prolonged, the tractor unit with digger is stopped by opening of electro -magnetic valve 159 which is connected with one-way pneumatic cylinder 160, where the rod pulls out the handle for turning off of the tractor engine, and after a short interval, returns it to the previous position. Pneumatic lifting and lowering of the plant detection mechanism 136, 137 and the wire brush 39 (in front of the tractor), is performed through the pneumatic valve 161 with manual control of the pneumatic cylinder with a pass-though rod 162 onto which an extension 163 is fixed with a support 164 so that the up and down movement can be monitored from the tractor cabin. Tractor speed regulation from 0 - maximum is performed through the one-way pneumatic cylinder 165 (by pressing of the rod on the foot accelerator pedal) receiving air from compressor 3 through pneumatic valve 166. The digger operates so that the supports 12 and 13 of the main beam 1 are connected to the tractor unit, and the inlet Cardan shaft 17 is connected to outlet tractor shaft from which the digger receives the rotary movement. Then, the pulley 18 activates through belt 19 the pulley 20 and two cylinder compressor 3 for production of compressed air. By mounting of support 4 onto support 14, the tractor unit is "united" with the digger, providing in this manner full stability, parallel and symmetrical conditions and normal position of all units 6 and 7 in relation to the longitudinal axis of the tractor unit. Cam disc 22, with outlets and empty fields along its periphery, is rotating driven by the movement of drive wheels 5, through the axle 21. Convex fields and empty fields are alternating, and their length is equal to the diameter of induction no-contact switch - sensor 133. Their operating principle consists of the following: if sensor 133 is connected to 24 V power supply it will recognize, without contact, metal on the cam disc 22, and transform it into electrical signal ("counting impulse" in this case), as it reads each centimetre of the path run by the drive wheel 5. In order to perform this operation, drive wheel 5 is rotating, sensor 133 is in fixed position and its distance from the convex field is several tenths of a millimetre. The whole mechanism is tightly closed for dust prevention. Power transmission by rotary movement from the outlet shaft 23, of reducer 2, is performed through chain-pulley 24, chain 25 and a group of chain- pulleys 26 up to the transmission shaft 27, which is connected through housing with bearings 28 to the support 15. On the transmission shaft 27, through pulleys 29 and belt 30 with belt fastener 31, the rotary movement is transmitted up to the pulleys 32 on the digging unit 6 or 7. Digging units 6 with horizontal shafts and digging unit 7 with vertical shaft can move along vertical axis depending on the ground configuration, and it is performed through the support 33 to which levers 34, wheel 35 and support with spring 36, which is fixed on the support 15 mounted on the main beam 1, are connected with a hinged joint. Supports of the plant detection mechanism 38, left mechanism 136 and right mechanism 137 containing induction sensors 134, 135 and one-way pneumatic cylinders 143, are connected to the shaft supports 37 with a detachable joint, and the assembly operates so that electrical signal is obtained (detailed description in operation information section) by swivelling of one of the one-way cylinders 143 through induction sensors 134 or 135. Wire brush 39 is made of many springs of thin "S" shaped material and it operates (within the "satellite" blades 76 operation area) with the surface layer of the ground where it is intended to move and turn over the soil close around the plant without damaging it. Leaves protectors - front 40, rear 49 and hoe 42, are used only with digging unit 6 with horizontal rotary shafts. Leaves protectors - front 40, have rubber elastic flags which are fitted onto the wire brush 39 at the height of leaves with the purpose to keep the leaves of the front plant 41 as far from "satellite" blades 76 as possible. Rear leaves protectors 49 operate in the following manner: on the axle 53 of the pneumatic rotary two-way cylinder 52, special bearing 54 is mounted (which, during rotating in one direction, transmits the power, and in the opposite direction, does not, i.e. only inside ring of the bearing 54 rotates) and four rubber leaves protectors 49 are fixed onto the bearing through support 45. The protectors are perpendicularly positioned one on another. Operation of the leaves protectors 49 and "satellite" blades 76 is synchronized by supplying of the compressed air from the same pneumatic valve 155. However, on the air supply duct for "satellite" blades 76, there is a throttle 167 slowing down their movement in addition to the resistance of the soil through which the "satellite" blades 76 are passing, while at the same time leaves protectors 49 turn around quickly and perform their function. When plants grow higher, the digging is performed with smaller number of springs in the wire brush 39 and without leaves protectors 40 and 49. Hoe 42 serves to make the first contact with ground and in this way to protect and enable gradual penetration of the digging unit 6 with horizontal rotary blades. Rotary horizontal unit 57 operates (like pneumatic two-way cylinder) with possibility of axial and rotary movement of the rod. When compressed air is supplied through the hoses with connections 64, pistons 66 are moving axially with the rod 61 and "satellite" blades 76 from their original position by the stroke's length. In case the compressed air is supplied through the hoses with connections 65, rod 61 with piston 66 and "satellite" blades 76 will return to its original position. When pulley 32 is rotating and compressed air is supplied, piston 66 is moving axially, rod 61 is rotating with inside ring of the bearing 73, and supports of blades 60 and 75 are also rotating with "satellite" blades 76. Rotary horizontal unit 57 is protected from all sides from dust and water with sealing rings 78 i conical corrugated rubber 77. Digging unit 7 with "vertical shafts" operates in the following manner: onto support 43 support 82 is mounted with a pulley 88 on it, which through pulley 29 and belt 30 receives "vertical" rotary movement, and through conical gears 87 and 89 "horizontal" rotary movement is performed through pulley with two grooves 90 and V-belt 91. Support 43 connects supports with plates 93 on which there are two-way pneumatic cylinders 94. On the fixed support 95 there is housing with bearing 96 and sleeve 97 on which there is a pulley with two grooves 98 which is connected to pulley with two grooves 90 through V-belt 91. Fixed support 95 is connected over the rotary element 99 joint to movable support 100 on which there is housing with bearings 101 through which vertical spindle 102 is passing with a pulley 103 on it, connected to belt 104 and pulley 98, and on the lower part there are rotary blades 105. Rotary blades receive rotary movement from pulleys 29, 88, 90, 98, 103 and belts 30, 91 and 104. Forward/backward movement of blades is performed through the hinge of the rotary element 99 by α angle, and two-way pneumatic cylinders 94 the rod of which is connected to housing with bearings 101 with detachable joint. They are receiving compressed air from electro-pneumatic valve 155. As our intention is to obtain the highest possible operation speeds, all valves in the system have dual operating position - "opened" and "closed", cylinders operate with rod "going out" and "going in" position, exterior blades from neighbouring rows meet each other with small overlap, digging only surface from plant to plant and only in one particular row. "Satellite" blades 76 are designed under certain angle, in order to avoid contact with plant leaves. When they are pulled out to maximum length, they dig the surface from plant 41 to plant 50, and when they are retracted, then they pass beside plants 41 and 50. Rotary blades 105 are constantly rotating in the ground and under plants leaves 106 and 107 in their particular row without making damage to plants or roots 106 and 107, and the ground surface that is not being cultivated by the blades, is cultivated by middle hoe 108 and side hoes 109. In order that tractor unit and digger, during their movement, could have position that corresponds to longitudinal axis of the tractor, i.e. to obtain parallel position of their wheels, for this purpose support 4 is used, and the mechanism for maintenance of parallel position 8 is mounted onto on the tractor steering wheel. Main parts of the mechanism are the toothed segment 111 and gear with lever 122, which on their middle positions have mark "0" with dash. When dashes come one under the other, it means that parallel position is obtained, and it is "maintained" with supports with pressure springs 123 under assistance of the operator. In case the operator wants to make a correction of direction by a few degrees up to the arrester 124 to the left or to the right, he can do it manually. Manual control of the steering wheel through mechanism for maintenance of parallel position 8 requires from operator to constantly watch the "0" marks and the terrain the tractor unit is approaching. In case digging operation is performed on large surfaces, and in case of operator being tired, mechanism for maintenance of parallel position 8 can be upgraded with electronic control which enables high level of reliability of monitoring of the movement direction during sawing, digging, earthing up, and even self-navigation during the digging. The system consists of Programmable Logic Controller (PLC) 11 which on the basis of software and peripheral induction switches 132, 133, 134 and 135 and performing elements of electro-magnetic valves 154, 155, 156 and contact device 157, controls the following processes: manual control of the steering wheel with electronic (sound and light) monitoring of the movement direction 9, control of automatic electronic pneumatic plant detection unit 10 during digging, automatic tractor steering wheel control by self-navigation during digging. PLC 11 is mounted into electric distribution cabinet 126 which is connected to 12 V DC battery through 24 V DC transformer 127. Concept of the system is based on the following procedure: the operator selects through cam switch (selector) 129 on the control panel 128, the control level he wants to use (individual control, combination of two controls, or all three controls at the same time). Once a control system is selected, under the cam switch (selector) 129 the signal light is turned on 130 which signals and warns the operator that the chosen control system is activated. When the control system is selected: Manual control of the tractor steering wheel with electronic (sound and light) monitoring of movement direction 9. Operation is performed through mechanism for maintenance of parallel position 8 on which there is a support with plate 119, by swivelling of which toward induction sensors 131, information is received on the position of the tractor steering wheel. So, if it is swivelled to the left or right, light signal 130 is obtained (left, right) as well as sound signal 132, warning operator on incorrect swivelling of the tractor steering wheel. In case for any reason, operation with PLC 11 is not possible, manual control of the tractor steering wheel can be performed through mechanism for the maintenance of parallel position 8. Upon selection of the control system for plant detection unit 10: - For digging procedure, it is applied both with diggers with horizontal rotary shafts and diggers with vertical, rotary shafts. When a plant, upon sprouting, becomes elastic when physically touched (does not remain in horizontal position, but returns into vertical position), the digging procedure can be performed. Plant detection within a row is performed with two plant detection mechanisms, the left 136 and the right 137, in which there are two very light pneumatic one-way cylinders 143, programmed in such a manner that their piston rods (antennas) extract in front of the plant, and upon the contact and the plant detection, they send information through induction sensors 134 or 135 to PLC 11 (signal is received only from one induction sensor 134 or 135) on the change of direction of electro-magnetic valves 154, 155, 156, i.e. on extraction of piston rods (antennas) of one-way pneumatic cylinders 143 and "satellite" blades 76 or blades 105 with vertical rotary shafts 102. Plant detection mechanism left 136 and right 137 operates in such a manner it has easily movable rotary element 169 (to which pneumatic one-way cylinder 143 is attached), which swivels and returns into its original position. Laminated spiral spring 145 has sufficient power to enable the cylinder piston rod 143 to bend the plant's leaf, and the stem of the plant swivels the piston rod and cylinder 143 up to the position in which plate 146 comes under induction sensor 134 or 135. At this moment signal is obtained, piston rod retracts, and cylinder 143 in its housing 170 returns into its original position, where it is protected against all external weeds. Within digging control system, signals from induction sensors 134, 135, are received by PLC 11 and based on preset values of counters Bl 150 B2 151 B3 152 (the values are preset on PLC 11 operator panel 168) electro-magnetic valves 154, 155, 156 are turned on / off through relay 153 in order to make it possible for digging to be performed according to the required cyclograph - stroke, preset in PLC 11. Induction sensor 133 gives to the counters Bl 150 B2 151 B3 152 the number of registered electric signals from cam disc 22, i.e. it registers the path run from plant 41 to the plant 50 or 106 to 107. Induction sensors left 134 or right 135 give to the counters Bl 150 B2 151 B3 152 electric signal for resetting of the performed counting and at the same time give start signals fro new counting. Counter Bl - 150 is given a number with which it will, upon performed counting, with electric signal, change direction of electro-magnetic valve 4/2 155, resulting in extraction of rotary "satellite" blades 76 and blades 105 with vertical shafts 102, and digging of the surface from plant 41 to plant 50 or from 106 to 107. Counter B2 - 151 is given a number when piston rods of one-way pneumatic cylinder, (hereinafter referred to as antennas 143), have to be extracted in front of the plant. When extracted, antennas come quickly in contact with plant 41 or 106, swivel and produce start signal, which also requires the change of status on electro-magnetic valves 154, 155, 156 (i.e. rotary blades and antennas 143 are retracted) and counting is reset at all three counters Bl 150 B2 151 B3 152. Counter B3 - 152 counts down signals a little longer then counter B2. Expressed in terms of length, it means the spacing of sowing or spacing between plants, including a plus/minus tolerance occurring during sowing. In case during operation the first one encounters plant 41 or 106 "antenna" 143 will reset all counts and position of electro-magnetic valves 154, 155, 156 will be changed (they are opened in initial position) and new counting will start. In case of no plant being present at the place where it is supposed to be, for any reasons, counter B3 153 will reset with given signal, which opens electromagnetic valve 156. Through the piston rod of one-way pneumatic cylinder 148 (receiving air through duct with a throttle 149), it comes in contact with support 147 on pneumatic cylinder 143, swivels "antennas" with cylinder 143, and in this way obtains start signal necessary for further operation of the machine without interruptions. According to this stroke, operation is repeated automatically for unlimited number of times.

During its operation, the digger follows one row, on the basis of which it performs digging of 4-6 rows. The tractor unit must follow the path and direction of sowing in order to prevent possible slipping of its wheels (wheels of the digger are of the same design as the wheels of the seeder).

- Automatic tractor steering wheel control by PLC 11 with software for self- navigation, operates in such a manner that PLC 11, based on information received from induction switches 134 or 135 from the digger, which are fitted in plant detection mechanism 136 and 137 (in front of the tractor), performs correction of the tractor movement so that it moves along the programmed path. In case tractor unit shifts from the programmed path, PLC 11 will switch on contactor 157 and collector motor 158, which will cause the tractor steering wheel to turn to the left or to the right until it restores the programmed path. Induction sensors 134 and 135 from the digger and in front of the tractor must be positioned in one line parallel to longitudinal axis of the tractor unit and digger. Operation with self-navigation is shown depending on the position of "antennas" 143 searching for plants in a row and giving exact position of the tractor unit and digger in relation to sprouted plants. All an operator has to do is to direct the tractor unit with digger to a row with sprouted plants, and the tractor will automatically follow the programmed path of unlimited length, in a precise and reliable manner.

If we present it in the following way:

1 - antennas activated

0 - antennas not activated

Z - collector motor Z - 0 - zero position

Z - 1 - movement to the left

Z - 2 - movement to the right possible encounters of antennas with plants are as follows:

1 1

I 1

Z-0 ideal straight movement, steering wheel "0" - "0" 1 0 0 1 0 1 1 0

I I 1 1 1 0 0 1

Z-0 straight movement, steering wheel close to "0" - "0"

For the above indicated movements PLC operates without activation of collector motor 158. Collector motor is activated in the following cases:

0 1

Z-l steering wheel should turn left - collector motor activated or

1 0

Z-2 steering wheel should turn right - collector motor activated.

It means that during operation, seven positions are possible, out of which none will cut the plant. Five of these positions give straight movement to the tractor, and two positions request change in order to obtain correct path. In case of irregularity during operation, sound signal 132 is heard, and if lasting longer, the tractor unit with digger is shut down by opening of electro-magnetic valve 159 which is connected to one-way pneumatic cylinder 160, where the piston rod pulls out the handle for tractor shut down, keeps it in this position for a shorter period of time, and when the engine stops, the piston rod returns the handle in its initial position. Pneumatic lifting and lowering of plant detection mechanism 136 together with wire brush 39 mounted in front of the tractor, is performed through pneumatic valve 5/2 161 with manual control from the tractor cabin. Compressed air is produced in compressor 3 and transported up to two- way pneumatic cylinder with pass-through piston rod 162 onto which extension 163 is fitted which passes through support 164, thus enabling the lifting / lowering operation to be monitored from the tractor cabin. Tractor speed regulation from 0 - max. is made through one-way pneumatic cylinder 165 by pressure of the piston rod of defined length - to the foot acceleration pedal (for sowing operation, movement of the pedal is larger, and for digging is smaller). Compressed air is produced in compressor 3 and distributed through pneumatic valve 166. Speed regulation is made through hand operated acceleration on up-hill and down-hill terrain sections. Design features are as follows: - Carrying structure and electro-pneumatic assemblies are unique for both digging variants i.e. with units (6) with horizontal rotary blades and with units (7) with vertical rotary blades. - Rotary digger operates in space between plants ± spacing tolerance, and its operation is not influenced by errors of accumulated tolerances between several plants. - Rotary digger with vertical shafts can operate with different row widths, while digger with horizontal shafts operates in one fixed width. - Compressed air consumption can be decreased by replacement of two- way pneumatic cylinders with one-way cylinders, with horizontal shafts diggers and vertical shafts diggers, resulting, however, in decreased operation speed. - Selected, installed electro-pneumatic, machine parts, provide maximum operation speed and are protected against shaking and dust. - Installed parts have certified long life. - Herewith described procedures, engineering and driving solutions for new products, completely close the circle of interrelations between operation of seeder, digger, mechanical weed cutter and earthing up machine. With proper application of these machines (chemicals would be completely avoided in agricultural production), food production would result in unpolluted and healthy food and high yields from large cultivation surfaces. - The digger operates in combination with pneumatic drill seeder with precise Venturi principle based seed delivery, which is applied with Federal Institute for Intellectual Property under No. 558/04.

Claims

PATENT CLAIMS

Electro-pneumatic digger with tractor self-navigation:

Consists of main beam (1) onto which the following parts are mounted: supports (15), reducer

(2) for rotary movement transmission, compressor (3) for production of compressed air, supports (4) for connection of digger to tractor unit, drive wheels (5), digging unit (6) with horizontal rotary shafts (for earthing of plants with stem), or unit (7) with vertical rotary shafts (for earthing of plants without stem). Automatic control of the system is achieved through PLC, mechanism (8) for maintenance of parallel position, plant detection unit (10) with Programmable Logic Controller PLC (11) and software for tractor self-navigation. According to requirement 1, characterized with, it has: Plant detection unit (10)

3. According to requirement 1, characterized with, it has: Digging units (6) with horizontal rotary shafts

4. According to requirement 1, characterized with, it has: Digging units (7) with vertical rotary shafts

5. According to requirement 1, characterized with, it has: Mechanism (8) fro maintenance of parallel position

6. According to requirement 1, characterized with, it has: Programmable Logic Controller PLC (11) with tractor self- navigation software.