This invention relates to apparatus and method for controlling or monitoring agricultural machines and more particularly pull-type agricultural machines which, in use, are hitched to a towing vehicle sucw-as a tractor.

With pull-type machines having components which have to be controlled from the towing vehicle certain disadvantages arise, one of which is that control cables have to be taken from the controls located in the cab of the towing vehicle to a connector on the towing vehicle which receives a complementary connector attached to cables leading to the components to be controlled on the agricultural machine. Cabling is cumbersome and furthermore also relatively expensive and, when installed on the towing vehicle, it is necessary to drill the cab structure for the through passage of the cables which can be detrimental to the sound-proofing which is installed in modern vehicles such as tractors. Another disadvantage is that if a farmer has a plurality of pull-type machines, then it is likely that he will need the same number of controls, connectors and sets of cabling in view of the different forms of control required for the various machines. In as much as there is a practical limit to the controls and cabling which can be accomodated in a given cab, it often happens that a farmer is restricted to one tractor fitted out to tow and control one machine, and another tractor fitted out to tow and control another machine. It would be far more convenient if any tractor or other vehicle could tow and control any machine.

Alternatively the control box of a given pull-type machine may be coupled without the use of any connectors via a flexible cable string to the machine components to be controlled. Such a control box is suited to be attached to a support within the tractor cab with the cable string passing through e.g. a cab window which therefore has to be opened and left open during the operation of the machine. Obviously, this is even more detrimental to the sound proofing of the cab and further adversely affects the air conditioning within the cab and permits the ingress- of dirt.

According to the overall concept of the present invention there is provided qn agricultural machine of the pull type fitted with means for receiving and/or transmitting encoded signals from and/or to a remote location, any received signals being used to control one or more components of the machine, and any transmitted signals being representative of one or more characteristics of the machine.

The invention may provide an agricultural machine of the pull-type and having a plurality of components to be controlled during operation, the machine further comprising a control unit mounted on the machine and having a plurality of control channels appropriate to the number and type of components to be controlled, the control unit also having a receiver operable to receive encoded command signals from a location remote from the machine, and decoding means responsive to a received signal and operable to decode the received signal and direct it to the appropriate channel, whereby the component associated with that channel is actuated in accordance with the command signal

Alternatively, the invention may provide an agricultural machine of the pull type and having one or more sensor means operable to sense one or more characteristics of the machine and to produce electrical output signals representative thereof, the machine also having transmitter means responsive to an output signal to produce therefrom an encoded signal and to transmit the encoded signal to a location remote from the agricultural machine.

According to another aspect of the present invention there is provided a method of controlling a pull-type agricultural machine comprising the steps of transmitting encoded command signals from a remote location to a receiver on the agricultural machine, decoding the received signals and passing the encoded command signals to the respective component or components to be controlled.

According to a still further aspect of the present invention there is provided a method of monitoring a pull-type agricultural machine comprising the steps of sensing the or each characteristic of the machine which is to be monitored, producing electrical signals representative of the or each sensed characteristic, encoding the electrical signals and transmitting them to a remote location for monitoring.

The encoded signals may be of the infra-red or radio-type. Encoded ultrasonic signals necessitate the installation of both the transmitter and receiver outside the tractor cab as such signals would not penetrate through the cab windows.

The remote control and/or monitoring of pull-type agricultural machinery which, in accordance with the present invention uses transmitter and receiver means capable of transmitting and receiving encoded signals, is advantageous in many respects. Indeed, it not only enables wireless remote control and/or monitoring, which in itself is aldready a major step forward, but it also enables the remote control and/or monitoring of a plurality of machine functions without any interference therebetween. Furthermore, the use of encoded signals enables remote controls and/or monitoring in widely varying environmental conditions (darkness, dark weather conditions, dirty cab windows, abundant sunshine...) and without suffering from any stray signals (abundant sunshine, citizen band radio signals...).

An agricultural machine in accordance with the present invention will now be described in greater detail, by way of example, with reference to the accompanying drawings, in which : -

• Figure 1 is a side view of the machine,
• Figure 2 is an electrical circuit diagram, and
• Figure 3 is a perspective view of a controller for controlling the machine of Figure 1.

The agricultural machine shown in Figure 1 is a basically conventional pull-type forage harvester 1 having a base frame, a pair of ground wheels 2, a drawbar 3 which is shown hitched to a towing tractor 4, and a drive shaft 5 which is shown connected to the power-take-off shaft of the tractor. The forage harvester further comprises a crop pick-up unit 7 which is movable generally vertically between a raised, transport position and a lowered, operative position, a chopper unit indicated generally at 8 but not seen in any detail, reversible feeder means, equally not shown and a crop discharge spout 9 connected to the outlet of the chopper unit and having the usual deflector 11 at its discharge end. The discharge spout 9 is fitted with a swivel control 12 for-moving the spout in azimuth, a vertical control 13 for moving the spout vertically, and a deflector control 14 for moving the deflector 11.

In accordance with the present invention, the forage harvester is fitted with a controller in the form of a receiver and actuator 15 capable of receiving encoded signals from a transmitter or controller 16 in the cab of the towing tractor 4. The receiver and actuator 15 is mounted on the machine via antivibration mounts. The controller 16 is of the conventional hand held type and, as shown in greater detail in Figure 3, comprises four control buttons 17, a range-change button 18, and a transmission window 19. For as long as a control button 17 is depressed, the controller transmits an encoded signal through the window 19 and, provided the window is directed generally towards the receiver and actuator 15 on the forage harvester, then the transmitted signal will be received thereby. If the range-change button 18 is depressed, then-a further four differently encoded signals are available via the control buttons 17. A permanent magnet 21 is attached to the housing of the controller 16 in such a position as not to interfere with any of the inductance devices forming part of the transmitter. The magnet 21 allows the controller to be attached to a metallic part of the.tractor cab convenient to the operator .

Figure 2 shows a circuit diagram of the receiver 15 which comprises a decoder 22 which decodes each received signal and outputs the decoded signal on the appropriate one of8output lines 23 ot 30. The decoded signal is amplified by an amplifier 31; all eight amplifiers being shown as a single block; and the amplified signal sent on the appropriate one of eight output lines 32 to 39 connected to respective relays 41 to 48.'The outputs 49 from the relays 41 to 48 are taken to connector 51 to which the motor or other actuator connections (not shown) and the battery connections (also not shown) are also taken. Each motor or actuator has two relays associated therewith in order that operation in one direction or another can be commanded to effect raising or lowering, or righthand or left-hand movement of the component being controlled, as appropriate. If a component to be controlled is single acting, such as an electromagnetic clutch, for example, then only one of the two relays allocated thereto is employed, it being convenient to provide a standard receiver and actuator with the maximum number of relays.

The receiver 15 is also fitted with four double-throw switches 52 to 55 which can be used to energise any of the eight relays 41 to 48 and thus control any of-the components of the forage harvester connected to the receiver and actuator 15. The switches 52 to 55 e.g. can be used to override the controller 16 for test purposes and can be used in a diagnostic role. It should be noted that the switches 52 to 55 are not essential to the operation of the present invention and may be omitted.

To illustrate the operation of the invention it will be assumed that the discharge spout swivel control motor 12 is connected to the relays 41 and 42 which in turn are connected to the decoder 22 via control channels represented by the output lines 32, 33 and 23, 24. When the operator depresses the button 17 on the controller 16 appropriate to say swivelling of the discharge spout 9 to the right, the encoded command signal will be transmitted through the window 19 to the receiver and actuator 15-(provided the window is directed thereat) and the decoder 22 will decode that signal and output it on line 23 to the amplifier 31. The signal is then amplified and sent on output line 32 to the relay 41 which is thus energised and delivers the command signal to the swivel control 12 via the associated output line 49 and connector 51. Thus the spout 9 will be moved to the right for as long as the appropriate controlled button 17 is depressed. Movement to the left is effected by depressing a different button 17 to generate a differently encoded command signal which is encoded as before but this time sent on output line ₂₄ to the amplifier 31 and thence on output line 33 to the relay 42. Control of the other components is effected in a generally similar manner, including the direction of rotation of the reversible feeder means to the chopper unit 8.

If more than eight controls are to be effected, as in the illustrated embodiment, then an appropriately sized controller and receiver/actuator may be provided although it is preferable to employ two receiver/actuators of Figure 2 in order to be able to standardise on components and yet meet all requirements in a simple manner.

It will be seen that the present invention affords a very simple and very effective apparatus and method for controlling the operation of an agricultural machine such as a forage harvester without involving cumbersome cabling connecting the machine to the towing vehicle and thus avoiding structural modification of the latter to accept the cabling. Furthermore, the machine can be controlled other than from within the towing vehicle, should this be necessary, by the operator taking the controller 16 from the tractor cab and operating it from any desired position, provided there is a direct "line of sight" from the controller to the receiver and actuator 15. Incidentally, it should be noted that encoded signals transmitted from within the cab have been found to penetrate a cab window which is reasonably dirty whereby the transmitter will be able to "see" the receiver/actuator 15 if the operator can see the machine which he normally needs to do in order to monitor the performance thereof.

It will be appreciated that the invention can be adapted to any pull-type machine : for example, it can be used with a pull-type round baler in which the drawbar, the tailgate and the twine-wrapping mechanism will normally be controlled. It can also be used with a pull-type combine harvester to control and/or monitor the numerous functions of such-a machine.

The present invention also covers the possibility of monitoring a harvesting machine as regards a harvesting or crop condition and/or a characteristic of one or more components, which characteristic may be associated with component wear, for example. In the illustrated embodiment, for example, the feeder means to the chopper unit 8 could be provided with a sensor which will produce an output signal indicative of whether the drive is in the forward or reverse mode, and the pick-up unit 7 may be provided to indicate whether the unit is in the raised, transport position or the lowered, operative position. The sensor output signals would be encoded and transmitted to a receiver in the tractor cab which will decode the signals and perhaps display the conditions represented thereby.