Abstract:
An automatically operated agricultural tree harvesting machine having systems for automatically steering, propelling and stopping the harvester machine to shake each tree, eliminating the need for the operator to steer or manually engage the shaker head. The system comprises a series of sensors to determine the location of each tree and a system for controlling the steering of the harvester and to determine the distance moved.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to mechanized agricultural tree harvesters that utilize shaker heads to shake fruit and nut trees, and more particularly to such a harvester having improved tree sensing devices and a related system that automatically detects, clamps and shakes trees. 
       BACKGROUND OF THE INVENTION 
       [0002]    Tree harvesters for shaking nut and fruit trees to cause nuts or fruit-to drop to the ground for harvesting to are well known in the prior art. R. W. Brandt, Jr. was a prolific inventor in this field and his U.S. Pat. Nos. 3,163,458; 3,220,268; 3,221,567; and 3,318,629 describe various features of tree harvesters and shaker heads that are still used in current devices. 
         [0003]    Applicant herein invented a tree shaking machine with automatic sensors described in U.S. Pat. No. 6,658,834, issued on Dec. 9, 2003. This application is an improvement on the machines described in that patent. 
         [0004]    When the harvest time of a particular crop occurs, thousands of trees in orchards become ripe at the same time. The shaking of these thousands of trees is a time consuming process, that must be completed quickly, and it is therefore advantageous to create systems that complete the tree shaking operating as quickly as possible, so that more trees can be harvested more rapidly, while the crop is ripe, and before it becomes over ripe and then spoiled. The present invention is an improved automation of the tree harvester shaking process, and it includes tree sensing devices along with a system for automatically deploying the harvester machine and the shaking head, clamping the tree, shaking the tree, releasing the tree and returning the shaker head to the harvester. 
         [0005]    Prior U.S. Pat. No. 6,658,834 describes a tree sensing device, mounted upon the harvester. Pre-determined tree distance values and other shaker head control parameters are input into a programmable logic control (PLC) device of the control system. When the harvester is driven to a location next to a tree, the operator initiates an automated tree shaking cycle in which the tree sensor locates the tree and provides distance values to the tree as input signals to the controller. The controller compares the distance values to the tree with the predetermined tree distance value and provides shaker head control signals that cause the shaker head to automatically move outward towards the tree. The shaker head outward motion is halted when the inputted distance values to the tree are equal to or less than the predetermined tree distance values. The control system then provides control signals to the shaker head components to cause the shaker head to clamp the tree, to shake the tree, to unclamp the tree and to move the shaker head back to the harvester. Further control input signals to the controller include engine RPM signals for controlling the engine RPM and tree shaking time signals for controlling the duration of the tree shaking step. 
       SUMMARY OF THE INVENTION 
       [0006]    The instant invention improves shaking technology by automatically steering, propelling and stopping the harvester machine to shake each tree, eliminating the need for the operator to steer or manually engage the shaker head. 
         [0007]    This new technology utilizes a series of sensors and/or vision systems. In one embodiment the harvester has 7 inputs, which comprise 4 sensors, 1 vision system, a joystick and a monitor.
       1) Sensor A is the existing sensor from the previous patent for finding the tree.   2) Sensor B is a linear potentiometer for determining the direction of the front steering.   3) Sensor C consists of a pulse pick-up in the drive motor for determining the distance to move by counting the revolutions of the front tire.   4) Sensor D utilizes a linear potentiometer for shaker head position and calculating the distance to the tree and the angular difference between trees.   5) Sensor E employs a vision system to identify the tree trunk and calculate the distance to the next tree.   6) A joystick provides digital input to start the system.   7) A monitor sets the parameters for engine speed and shaker duration.       
 
         [0015]    The software is contained within a programmable logic control device (PLC) which calculates the distance from machine to tree and tree to tree. The output signal then modifies the steering controls to maintain optimum shaker performance as follows:
       1) The controller outputs a signal to the controller on the ground drive which propels the machine.   2) The controller output provides the power for the electric over hydraulic functions including steering, clamp/shake, unclamp and in/out.       
 
         [0018]    The system operates as follows:
   Step 1—The operator drives to the first tree and positions the shaker parallel to the tree row, aligning the shaker head with the first tree to be shaken.   Step 2—The operator then presses a button on the joystick to start the automatic shake cycle (pre-existing patent). As the shaker goes through its cycle it will measure the distance to the tree, via Sensor D. The measurement takes place as the head extends to the tree.   Step 3—The shaker will then take the information from Sensor E (distance to the next tree) and propel the machine forward. While propelling forward, Sensor C determines when to stop.   Step 4—Once again the automatic cycle starts. Now Sensor D takes a new distance measurement to the next tree, as it extends the shaker head.   Step 5—A calculation from the first tree distance to the second tree distance is made. The difference between the two will now be used to figure the angular adjustment needed on the front steering caster. A signal will actuate a valve to turn a steering caster until Sensor B reaches the desired angle pointing the shaker in the correct direction.   Step 6—Forward movement of the machine begins and the machine moves to the recalculated position and the cycle then repeats itself.   
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0025]      FIG. 1  is a perspective view of a tree harvester including an automatic tree sensing device and system of the present invention; 
           [0026]      FIG. 2  is a side elevational view of the harvester depicted in  FIG. 1 ; and 
           [0027]      FIG. 3  is a top plan view of the harvester depicted in  FIGS. 1 and 2 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]      FIGS. 1-3  depict a harvester machine that is improved by the inclusion of the automatic machine movement, tree sensing and shaking system of the present invention.  FIG. 1  is a perspective of view of the harvester machine,  FIG. 2  is a side elevational view thereof, and  FIG. 3  is a top plan view thereof. As depicted in  FIGS. 1-3 , the harvester  10  includes a body  14  enclosing a drive engine, a forwardly disposed operator&#39;s cab  18 , a tree clamping and shaking head  22  that is mounted to the body  14  such that the operator can view the tree clamping and shaking process, and a single front steering wheel  26 , mounted on a caster, for maneuvering the harvester  10 . The shaker head  22  is movably mounted upon an outwardly projecting support boom  30 , such that the harvester can be positioned next to a tree and the shaker head  22  then moved outwardly to clamp and shake the tree. The shaker head  22  includes two jaws  34  and  35  having shaking pads  38  and  39  that are used to clamp and shake the tree. 
         [0029]    In operation, the operator drives to the first tree and positions the shaker head  22  parallel to the tree row, aligning shaker head  22  with the first tree to be shaken. Sensor A,  50 - 51 , detects the presence and location of the first tree. The operator then presses a button on the joystick in the cab to start the automatic cycle of steps. Support beam  30  moves out towards the tree. As the shaker  22  goes through its cycle, sensor D,  52  will measure the distance to the tree. The measurement takes place as shaker head  22  extends to the tree. Shaker head  22  stops when a beam between sensors  50  and  51  is broken by the tree. Jaws  34  and  35  clamp and shake the tree and then unclamp the tree and move back to the harvester  10 . The length of time that the tree is shaken is predetermined and set in the controller (PLC). 
         [0030]    When shaker  22  has completed shaking the tree and retracts, it will then take the information from sensor E,  54 , having a field of view to measure the distance and angle to the next tree, and propel the machine forward. While propelling forward, sensor C,  56  determines when to stop by measuring the distance the machine has moved forward. This measurement is done by a pulse pick-up sensor C,  56  measuring the revolutions of tire  60 . The machine is moved forward automatically by the PLC being operably engaged to the harvester engine to control the throttle of the engine, and stops when the measured distance has been traveled, as stated above. 
         [0031]    Once again, the automatic cycle starts. Shaker  22  is extended to grasp and shake the second tree. Now sensor D,  52 , takes a new distance measurement to the next tree, as it extends shaker  22 . A calculation from the first tree to the second tree is made. The distance between the two is now used to figure the angular adjustment needed on the front steering caster. A signal actuates a valve to turn a steering caster on single forward wheel  26 , until sensor B,  58 , reaches the desired angle pointing shaker  22  in the right direction. Forward movement begins to the recalculated position and the cycle of steps then repeats itself. 
         [0032]    With reference to the control system, the basic structure is described in U.S. Pat. No. 6,658,834 using a programmable logic control device (PLC). What is added to that system are the additional sensors and controls, providing the additional information needed, as described above, to now propel the machine automatically from tree to tree, putting it in the proper position for the shaker to grasp and shake each tree, rather than the operator driving the machine from tree to tree. 
         [0033]    While the invention has been shown and described with reference to particular preferred embodiments, it will be understood by those skilled in the art that various alterations and modifications in form and detail may be made therein. Accordingly, it is intended that the following claims cover all such alterations and modifications as may fall within the spirit and scope of the invention.