Patent Description:
Round balers are well known in the art. Such balers pick up a harvested crop from a swath or windrow and feed the harvested crop into a baling chamber where it is formed into a cylindrical bale.

The harvested crop is drawn into the baler by a driven pickup apparatus and directed to a baling chamber. The baling chamber includes driven means such as rollers in order to form a bale within the baling chamber. These drive means are conveniently driven from the Power Take Off (PTO) of a tractor towing the baler. It is known, for example from <CIT> to provide a split drive from the PTO to each of the feeding side (pickup) and forming side (baling chamber) drive means. The load on each of these drives will be dependent upon the flow rate of harvested crop being processed by each of the feeding side and forming side drives. The flow rate of harvested crop can be increased by increasing the speed of the tractor towing the baler over the swath or windrow and decreased by decreasing the speed of the tractor. The flow rate is also affected by the density of the harvested crop in the swath or windrow such that an operator may wish to increase the speed of the tractor when approaching a swath or windrow of low density in order to maintain an even flow rate of harvested crop to the baling chamber or decrease the speed of the tractor in order to avoid overloading when processing a swath or windrow of high density.

Round balers are usually fitted with an overload device that limits the maximum power that can be processed by the baler drive means. It is usually up to the experience of an operator to understand if the operator is very close to the maximum or if the operator could go quicker or should reduce speed.

It is an advantage of the present invention that these problems are addressed, in particular by allowing an operator to make better decisions regarding a potentially imminent overload situation.

A method of controlling a tractor/baler combination is known from <CIT> which assesses the flow rate of harvested crop in the baler, compares the assessed flow rate with a recommended flow rate and if the assessed flow rate differs from the predetermined flow rate by more than a predetermined amount, changes the speed of advancement of the tractor/round baler combination, and so changes the flow rate of the harvested crop in the round baler.

A method of controlling a tractor/round baler combination is also known from <CIT>which the torque of the baling chamber is monitored via a torque sensor.

According to a first aspect of the present invention, a method of controlling a tractor/round baler combination in accordance with claim <NUM> is suggested.

Preferably the flowrate of harvested crop material is determined by the feeding side torque sensor measuring a torque of a drive shaft driving a pick up unit of the round baler.

Preferably the step of changing the speed of advancement of the tractor/round baler combination comprises the control unit sending a signal to a user terminal to signal to an operator that the speed of advancement of the tractor/round baler combination should be changed. Alternatively, the step of changing the speed of advancement of the tractor/round baler combination comprises the control unit sending a signal to an engine management system of the tractor that the speed of advancement of the tractor should be changed.

Further preferred embodiments are defined by the appended claims.

According to another aspect of the present invention a tractor/round baler combination in accordance with claim <NUM> is suggested.

Referring first to <FIG> a baler <NUM> which creates round bales from a harvested crop is shown. In operation, the baler <NUM> is towed by an agricultural vehicle, such as a tractor <NUM>, to which the baler is connected (<FIG>).

A pick up unit <NUM> picks up harvested crop material from a ground surface while the baler is towed over the ground. The harvested crop material is arranged in a swathe or windrow on the ground in order to be picked up by the baler <NUM>.

A conveying rotor <NUM> is provided to transfer the harvested crop material from the pickup unit <NUM> to a baling chamber within the baler <NUM>. A cutting assembly <NUM> may also be provided adjacent the conveying rotor <NUM>.

The baler <NUM> comprises a front housing <NUM> and a tailgate or discharge gate <NUM>. The tailgate <NUM> is pivotally mounted to the front housing <NUM> about a pivot axis <NUM>.

In the illustrated embodiment, the baling chamber is a variable diameter chamber. The baling chamber is defined by a number of parallel pressing belts <NUM> arranged around a number of rollers including driven rollers <NUM> and idler rollers <NUM>. The baling chamber also includes three further pressing rollers <NUM>,<NUM>,<NUM>. The first and second pressing rollers define an inlet <NUM> through which the harvested crop material is introduced into the baling chamber. A wrapping material inlet <NUM> is defined between the third pressing roller <NUM> and an adjacent idler roller <NUM>.

As harvested crop material is introduced into the baling chamber, rotation of the harvested crop material in the direction of arrow A causes a bale B to be formed within the baling chamber.

The baler <NUM> also includes a wrapping apparatus <NUM>. In the illustrated embodiment the wrapping apparatus <NUM> is mounted on the front housing <NUM> of the baler <NUM>. The wrapping apparatus <NUM> includes a reservoir in which a reel <NUM> of wrapping material <NUM> may be stored. The wrapping material may comprise any suitable material. Suitable wrapping materials include netwrap or film. A leading edge of the wrapping material is drawn from the reel <NUM> by a pair of dispensing rollers <NUM>, <NUM> before being introduced into the baling chamber by way of the wrapping material inlet <NUM>.

When a bale of suitable size has been formed, the wrapping apparatus <NUM> is actuated and several layers of the wrapping material <NUM> are placed around the rotating bale B. The wrapping material <NUM> is then severed by a suitable mechanism (not shown). The tailgate <NUM> is then displaced by any suitable mechanism in order to allow the wrapped bale to be ejected from the bale forming chamber.

<FIG> shows schematically an example drive arrangement of the baler. The PTO shaft <NUM> of the tractor drives an input shaft <NUM> of the baler <NUM>. An overload clutch <NUM> is arranged in the input shaft <NUM> of the baler <NUM>. In the event of an overload situation, the overload clutch <NUM> interrupts the input shaft <NUM> and disconnects the powertrain leading from the tractor motor to the rotating parts of the baler <NUM>. It will be appreciated that such an overload situation is undesirable. It is an advantage of the present invention that operation of the overload clutch <NUM> is sought to be avoided.

The input shaft <NUM> ends in a transmission assembly <NUM>. In the illustrated embodiment, the transmission assembly <NUM> drives a feeding side output shaft <NUM> and a forming side output shaft <NUM>. Both shafts start in the transmission assembly. In the illustrated embodiment, the transmission assembly includes a bevel gear <NUM>. The transmission ratio between the input shaft <NUM> and the feeding side output shaft <NUM> may differ from the transmission ratio of the input shaft <NUM> and the forming side output shaft <NUM> by adapting the bevel gear <NUM>.

In the illustrated embodiment, the feeding side output shaft <NUM> drives the pickup unit <NUM> and the conveying rotor <NUM>, while the forming side output shaft <NUM> drives the pressing rollers <NUM>,<NUM>,<NUM>, the driven guiding roller <NUM> and the driven pulling roller <NUM>.

A feeding side torque sensor <NUM> and a forming side torque sensor <NUM> are arranged within the transmission assembly <NUM> and provide signals to a control unit <NUM>. The control unit <NUM> also provides signals to control operation of the baler and operation of the tractor <NUM>. Conveniently the signals are provided by way of a suitable data communication network <NUM> such as one compliant with the ISOBUS standard (a network in conformance to the ISO <NUM>).

An operator may send signals to the control unit <NUM> by use of a user terminal <NUM>. The user terminal is conveniently located within the operator's cab of the tractor <NUM>. The user terminal <NUM> may include a keypad and/or a touch screen for communication by the operator with the control unit <NUM>. The control unit <NUM> may also send signals to the user terminal <NUM> to provide information to the operator regarding operation of the tractor <NUM> and the baler <NUM>. The user terminal <NUM> may include a display screen and, optionally speakers, for communication by the control unit <NUM> with the operator.

The control unit <NUM> may conveniently comprise a single processor located on the tractor <NUM> or its functions may be split between a first processor located on the tractor <NUM> and one or more additional processors located on the baler <NUM>, the additional processor(s) being in electronic communication with the first processor.

The control unit <NUM> is also able to access a suitable memory <NUM>. The memory <NUM> may take any suitable form and is in electronic communication with the control unit <NUM>. The memory <NUM> is adapted to store, in any suitable manner such as a database or look up table, values for the maximum recommended or optimal torque for the feeding output shaft <NUM> and the maximum recommended or optimal torque for the forming output shaft <NUM>.

The optimal torque values can be set according to a bale cycle status of the baler <NUM> since the expected torque value on the forming output shaft <NUM> will be greater the larger the forming bale in the baling chamber.

In a first method of the present invention, signals from each of the feeding side torque sensor <NUM> and a forming side torque sensor <NUM> are sent to the control unit <NUM> (steps <NUM>,<NUM> <FIG>).

The control unit <NUM> then interrogates the memory unit <NUM> to determine the maximum recommended or optimal torque for the feeding output shaft <NUM> and the maximum recommended or optimal torque for the forming output shaft <NUM> (steps <NUM>,<NUM>).

The control unit <NUM> then determines whether both of the feeding output shaft torque and the forming output shaft torque are below a predetermined tolerance value of their respective optimal torque values, whether one of the feeding output shaft torque and the forming output shaft torque are within a predetermined tolerance value of their respective optimal torque values or whether one of the of the feeding output shaft torque and the forming output shaft torque are above their respective optimal torque values (step <NUM>).

If both of the feeding output shaft torque and the forming output shaft torque are below a predetermined tolerance value of their respective optimal torque values, the control unit <NUM> will send a signal to the user terminal <NUM> to communicate to the operator that the speed of the tractor <NUM> may be safely increased (step <NUM>).

If one of the feeding output shaft torque and the forming output shaft torque are within a predetermined tolerance value of their respective optimal torque values, the control unit <NUM> will send a signal to the user terminal <NUM> to communicate to the operator that the speed of the tractor <NUM> may be maintained (step <NUM>).

If one of the feeding output shaft torque and the forming output shaft torque exceeds their respective optimal torque values, the control unit <NUM> will send a signal to the user terminal <NUM> to communicate to the operator that the speed of the tractor <NUM> should be decreased as soon as possible in order to avoid an overload situation (step <NUM>).

In a second method of the present invention, as in the first method, signals from each of the feeding side torque sensor <NUM> and a forming side torque sensor <NUM> are sent to the control unit <NUM> (steps <NUM>,<NUM> <FIG>).

The control unit <NUM> again then interrogates the memory unit <NUM> to determine the optimal torque for the feeding output shaft <NUM> and the optimal torque for the forming output shaft <NUM> (steps <NUM>,<NUM>).

The control unit <NUM> then, again as in the first method, determines whether both of the feeding output shaft torque and the forming output shaft torque are below a predetermined tolerance value of their respective optimal torque values, whether one of the feeding output shaft torque and the forming output shaft torque are within a predetermined tolerance value of their respective optimal torque values or whether one of the of the feeding output shaft torque and the forming output shaft torque are above their respective optimal torque values (step <NUM>).

If both of the feeding output shaft torque and the forming output shaft torque are below a predetermined tolerance value of their respective optimal torque values, the control unit <NUM> will send a signal to the engine management system <NUM> of the tractor <NUM> to increase the speed of the tractor <NUM> and a signal to the user terminal <NUM> to communicate to the operator that the speed of the tractor <NUM> has been increased and, optionally a signal to the user terminal <NUM> to communicate to the operator the feeding output shaft torque and the forming output shaft torque detected and/or how far below the predetermined tolerance value of their respective optimal torque values the feeding output shaft torque and the forming output shaft torque detected are (step <NUM>).

If one of the feeding output shaft torque and the forming output shaft torque are within a predetermined tolerance value of their respective optimal torque values, the control unit <NUM> will send a signal to the engine management system <NUM> of the tractor <NUM> to maintain the speed of the tractor <NUM> and a signals to the user terminal <NUM> to communicate to the operator that one of the feeding output shaft torque and the forming output shaft torque are within a predetermined tolerance value of their respective optimal torque values and that the speed of the tractor <NUM> has not been changed, and optionally a signal to the user terminal <NUM> to communicate to the operator the feeding output shaft torque and the forming output shaft torque detected and/or that one of the feeding output shaft torque and the forming output shaft torque are within a predetermined tolerance value of their respective optimal torque values, for example by sounding a warning signal or causing at least a portion of the display of the user terminal <NUM> to change colour (step <NUM>).

If one of the feeding output shaft torque and the forming output shaft torque exceeds their respective optimal torque values, the control unit <NUM> will send a signal to the engine management system <NUM> of the tractor <NUM> to decrease the speed of the tractor <NUM> and send a signal to the user terminal <NUM> to communicate to the operator that the speed of the tractor <NUM> has been decreased in order to avoid an overload situation (step <NUM>).

Claim 1:
A method of controlling a tractor (<NUM>)/round baler (<NUM>) combination comprises the steps of:
(i) advancing a tractor(<NUM>)/round baler(<NUM>) combination through a swath or windrow of a harvested crop material with a tractor PTO operating at a constant speed to power a drive of a baling chamber of the round baler (<NUM>) and the round baler (<NUM>) operating to pick up harvested crop material;
(ii) during step (i) assessing with a control unit (<NUM>) receiving signals from a feeding side torque sensor (<NUM>) and a forming side torque sensor (<NUM>) in order to assess the flowrate of the harvested crop material in the round baler and the torque of the baling chamber drive
(iii) comparing the assessed flowrate with an optimal flowrate stored in a memory unit (<NUM>) of the control unit (<NUM>) and the torque of the baler chamber drive with an optimal baler chamber drive torque stored in the memory unit (<NUM>) of the control unit (<NUM>); and
(iv) if the assessed flowrate differs from the optimal flowrate by more than a predetermined amount or the assessed torque of the baler chamber drive differs from the optimal torque by more than a predetermined amount, the control unit (<NUM>) sending a signal to change the speed of advancement of the tractor (<NUM>)/round baler (<NUM>) combination, and hence changing the flowrate of biological matter in the round baler (<NUM>) and the torque of the baler chamber drive.