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FIELD OF THE INVENTION  
         [0001]    The invention pertains to an operating system for a tractor-mounted loader.  
         BACKGROUND OF THE INVENTION  
         [0002]    Various types of loading devices are known, e.g., in the form of farming tractors logging tractors or industrial tractors with a front loader or rear loader that is constructed in the form of a wheel loader or the like. The operation of these loading devices is quite complex because the base vehicle needs to be driven and steered while the loader frequently needs to be operated simultaneously.  
           [0003]    It is also known (ASAE Paper 993186) to utilize speech recognition systems in agricultural machines in order to store information on the processed field in memory during the operation of the machine and to subsequently use this information during the additional processing of the field.  
           [0004]    The problem to be solved with the invention can be seen in the fact that this technology can only be utilized in a very limited field of application.  
         SUMMARY OF THE INVENTION  
         [0005]    According to the present invention there is provided an improved control system for a tractor-mounted loader.  
           [0006]    An object of the invention is to provide a control system for a tractor-mounted loader which employs voice recognition technology, whereby an operator may control the loader, at least in part, by speaking.  
           [0007]    A more specific object of the invention is to provide a loader control system, according to the preceding object, wherein the voice recognition system is responsive to short, terse and clear comments, e.g., “stop”, “go”, etc.  
           [0008]    Yet a more specific object of the invention is to provide a loader control system embodying voice recognition technology that operates for causing the loader to raise a load to a certain height, in response to an exemplary voice command, such as “truck” and to dump the lifted load in response to another voice command, such as “dump”.  
           [0009]    Another object of the invention is to provide a speech-controlled loader wherein certain operators can be excluded from operating the loader in accordance with the function-sensitive vocabulary that is loaded into the main memory of the computer used in the system.  
           [0010]    These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The sole figure is a schematic right side view of an agricultural tractor carrying a front-mounted loader, and embodying a voice-controlled, electro-hydraulic control system in accordance with the principles of the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0012]    The figure shows a loading device  10  with a carrier vehicle  12  and a loader  14 , with the loading device  10  being operated by an operating system  16  according to the invention.  
         [0013]    The carrier vehicle  12  is here disclosed in the form of an agricultural tractor, with the loader  14  being shown as a front-mounted loader. Other arrangements could be used as well, for example, a rear-mounted loader, an industrial wheel loader, a telescopic loader, etc.  
         [0014]    The carrier vehicle  12  includes an undercarriage  18  supported on front and rear pairs of drive wheels  20 , with the forward pair of wheels  20  being steerable. An operator&#39;s station or platform  22  is positioned over a rear section of the undercarriage  18 . The undercarriage is equipped with various components, e.g., a transmission, an engine, hitches and the like, as it is known, for example from conventional agricultural tractors, and are not further described. The carrier vehicle is also equipped with an adjusting device  24 . The operator&#39;s station  22  includes, among other things, a steering wheel  26 , an actuating device  28  and a cab  30 , in which there is space for at least one operator. The steering wheel  26  is conventional and may be equipped with a not-shown central instrument unit.  
         [0015]    The aforementioned actuating device  28  merely represents one of a series of actuating devices for the transmission, the engine and the like, with said actuating device serving to control the loader  14 . This actuating device  28  is conventionally realized mechanically in the form of a lever and acts upon the adjusting device  24  via a rod assembly, a cable pull or electrically. The actuating device  28  has, in principle, priority over the operating system  16 .  
         [0016]    It is not imperative that there be a cab  30 , there could instead be just a roof that is arranged on a frame, a canopy top, a covered bracket or simply a post on which components can be mounted.  
         [0017]    In the embodiment shown, the loader  14  is constructed in the form of a front loader as it is known from the agricultural industry and communal organizations. Among other things, the loader  14  contains posts  34 , a loader boom or arm structure  36 , a work tool  32 , servomotors  38  for the loader boom  36 , and at least one servomotor for the work tool  32 .  
         [0018]    The loader  14  is disclosed in this embodiment serves, for example, for loading bulk material that lies on the ground into a container such as that of a trailer or hauling truck, for example. In this case, the loading device  10  pushes the work tool  32 , here disclosed as a bucket, into the heap of bulk material, tilts the tool  32  backwards, raises the loader boom  36 , moves the carrier vehicle  12  back towards the trailer or truck container, stops the carrier vehicle and then tilts the tool  32  forward to dump its load. After this the process begins anew.  
         [0019]    In another exemplary application, where the carrier is in the form of a fork lift truck, a palette situated on the ground is raised by a palette fork and placed onto a transport vehicle.  
         [0020]    The tool  32  is connected in a pivoted fashion to the front end region of the loader boom  36  in a lower bearing  42  and to the servomotor  40  in an articulated fashion in an upper bearing  44 . Its position is controlled by the operating system  16  or the actuating device  28 .  
         [0021]    The posts  34  accommodate the respective rear end regions of the loader boom  36  in a vertically pivoted fashion in a bearing  46  and are connected in a stable fashion to the undercarriage  18  by consoles  48 . The posts  34  contain a second bearing  50  for the rear end of the servomotor  38 .  
         [0022]    The loader boom  36  is composed of two arms that are rigidly connected to one another and are angled between their ends to form an angle between approximately 130° and 150°. The entire boom  36  can be vertically pivoted about the bearing  46  by means of the servomotors  38 . Each servomotor  38  is constructed in the form of a single-acting hydraulic motor; however, this is not absolutely imperative. Alternatively, it would also be conceivable to utilize a double-acting hydraulic motor or even an electric motor. The servomotor  38  is supported in a pivoted fashion with its rear end region in the bearing  50  and with its front end region in a not-shown bearing arranged in the region in which the two arms of the boom  36  are connected to one another. The boom  36  is raised by means of the servomotors  38 , with the boom  36  being lowered due to gravitational force. The servomotors  38  are supplied with power by the adjusting device  24 .  
         [0023]    The servomotor  40  is also constructed in the form of a hydraulic motor, however, it is a double-acting hydraulic motor that operates for adjusting the tool  32  in both directions about the pivotal connections  42 . The utilization of an electric motor would also be conceivable in this case. The servomotor  40  engages into the bearing  44  with its front end region, and its rear end region is held in a pivoted fashion in the region in which the two arms of the boom  36  are connected to one another. However, the latter aspect is not shown in the figure. The servomotor  40  serves for adjusting the tool  32  and is supplied with power from the adjusting device  24 .  
         [0024]    The operating system  16  contains a speech recognition device  52 , a microphone  54 , an activating device  56 , a sensor  58  that is assigned to the boom  36 , a sensor  60  that is assigned to the tool  32  and an interface  62  with the adjusting device  24 .  
         [0025]    The speech recognition device  52  is contained in an on-board computer that is usually arranged on the driver&#39;s platform  22 . For training and calibration purposes, the on-board computer can also be detached and, for example, connected to another computer. The speech recognition device  52  contains an automatic speech recognition program as it is known from the state of the art and, for example, explicitly described in the initially cited document that forms part of the state of the art. Such a speech recognition program contains a memory  78  with words, sentences, or parts of sentences that can be assigned to the word, sentence or part of a sentence which is spoken by the operator and recorded by the microphone  54 . A signal is assigned to each word, sentence or part of a sentence in the memory  78 . These signals are routed to the adjusting device  24  via the interface  62  and cause a certain movement of the adjusting device. The memory  78  may be realized, in particular, loaded, in such a way that it also recognizes the operator and only performs the respective function once it has determined that the operator is an authorized operator. The memory  78  may also contain and assign terms in several languages such that operators who speak different languages are able to operate the loader. In order to ensure that such a program is able to reliably recognize and assign the terms, it is necessary to regularly perform speech training that can be carried out separately of the loading device  10  while the on-board computer is detached. The speech recognition device  52  may also be equipped with various memories  78  for different attachments such that, for example, an attached sowing or spraying device can also be controlled. The speed of the adjustment can also be controlled by correspondingly defined terms. The speech recognition device  52  is operated with an external or internal voltage source as indicated in the figure.  
         [0026]    The microphone  54  is situated in the immediate vicinity of the operator and mounted on the cab  30  in this embodiment. Alternatively, the microphone  54  could also consist of a microphone with or without a cable which is carried by the operator or integrated into the steering wheel  26  or a windshield. In this respect, the only important aspects are that a reliable recording of the speech takes place and that the spoken terms are forwarded to the speech recognition device  52  by means of the shown connection that is not illustrated in greater detail, for example, a wire or in a wireless fashion.  
         [0027]    The activating device  56  is situated in the immediate vicinity of the operator and symbolically illustrated on the steering wheel  26 . However, this is not absolutely imperative. Alternatively, the activating device  56  could also be situated on the actuating device  28 . In any case, it is connected to the speech recognition device  52  by means of a wire or in a wireless fashion and has the function of permitting or blocking the speech recognition by means of the microphone and the speech recognition device  52 . This is intended to prevent a spoken term from causing an undesired adjusting signal. The activating device  56  may be designed in such a way that it basically blocks speech recognition and only allows such speech recognition if it is intentionally actuated. The activating device  56  could also be provided with or connected to a safety device that, for example, blocks the speech recognition if a high driving speed is reached, if the operator is under the influence of alcohol, etc.  
         [0028]    The sensor  58  determines the position between the boom and at least one post  34  within the region of the bearing  46 , and the distance between the ground and the tool  32  is derived from said position. This sensor  58  could also measure the position of the servomotor  38  relative to the post  34 . A sensor  58  of this type which, for example, is constructed in the form of a rotary potentiometer makes it possible to stop the movement of the boom  36  once it has reached a certain position that is predetermined by a speech-derived signal. The sensor  58  is also connected to the speech recognition device  52  by means of a wire or in a wireless fashion and is fed corresponding signals to the speech recognition device.  
         [0029]    The sensor  60  is arranged in the region of the bearing  42  and consequently determines the position of the tool  32  relative to the boom  36 . The sensor  60  may simply determine the end positions such that the loading or unloading of the tool  32  can be easily controlled and monitored.  
         [0030]    The interface  62  serves for connecting the operating system  16  to the adjusting device  24 . The utilization of such an interface  62  makes it possible to realize and operate the adjusting device  24  independently of the operating system  16 . The interface  62  also makes it possible to control valves that are used for the adjustment of the servomotors  38  and  40  and are described in greater detail below.  
         [0031]    The adjusting device  24  is constructed in the form of a hydraulic system and contains a reservoir  64 , a pump  66 , a pressure control valve  68 , a valve  70  for the boom  36  and a valve  72  for the tool  32 .  
         [0032]    The reservoir  64 , the pump  66  and the pressure control valve  68  are conventionally constructed in the form of an open system and connected to one another. Consequently, these components do not require a more detailed description.  
         [0033]    The valve  70  is constructed in the form of a three-position, three-way valve and set into a locked position a, a supply position b, or a discharge position c by means of two solenoids  74 . In the locked position a, the servomotor  38  is blocked and the pump  66  conveys a pressure medium into the reservoir  64 . In the supply position b, a pressure medium is supplied to the servomotor  38  such that it extends and lifts the boom  36 . In the discharge position c, the pressure medium is able to flow back into the reservoir  64  such that the boom  36  is lowered by the effect of gravity. The solenoids  74  are connected to the voice recognition device  52  via the interface  62  by means of a wire or in a wireless fashion.  
         [0034]    The valve  72  serves for controlling the servomotor  40  that adjusts the position of the tool  32  and is constructed in the form of a three-position, four-way valve that can also be set into a locked position a, a retracted position b and an extended position c by means of solenoids  76 . The solenoids  76  are connected to the speech recognition device  52  via the interface  62  by means of a wire or in a wireless fashion. In the locked position a, the servomotor  40  is blocked and the pressure medium conveyed by the pump  66  flows back into the reservoir  64 . IN the retracted position b, the pressure medium is supplied to the end of the servomotor  40  on the side of the piston rod. In the extended position c, the pressure medium is supplied to the end of the servomotor  40  on the side of the piston. Four connections lead from the interface  62  to the hydraulic system  24 . The hydraulic system  24  may also be modified such that it includes two servomotors  38  and/or  40 . This would correspondingly increase or decrease the number of connections at the interface  62 .  
         [0035]    It is quite obvious that the posts  34 , the servomotors  38 , the consoles  48  and the respective bearings  42 ,  44 ,  46  and  50  are provided twice, namely, on each side of the undercarriage  18 .  
         [0036]    According to the previous description, the new operating system  16  functions as described below.  
         [0037]    As long as the activating device  56  is not actuated, the movement of the boom  36  and the tool  32  is controlled by the actuating device  28 , i.e., without the participation of the operating system  16 .  
         [0038]    If the control should be effected by means of the operating system  16  according to the invention, the operating system needs to be connected to the adjusting device  24  via the interface  62 . Subsequently, the activating device  56  is actuated and a command is transmitted to the speech recognition device  52  by means of the microphone  54 . This command consists, for example, the word “lift”. The speech recognition device  52  recognizes the command “lift” and assigns this command to a signal. This signal causes a current to be applied to the solenoid  74  of the valve  70  which moves said valve into the supply position b. This causes the servomotors  38  to be extended and the boom  36  to be raised. This lifting movement is interrupted by the sensor  58  which recognizes that the boom  36  has reached a certain height or the maximum height, or the operator issues a command, e.g., “stop”. This command causes the electrical current to the solenoid  74  in question to be cut off and the valve  70  to be pressed back into the locked position a by means of centering springs. The tool  32  can be actuated or the boom  36  can be lowered by means of additional, pre-programmed commands.  
         [0039]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.

Summary:
A tractor is equipped with a front end loader including a boom mounted for being raised and lowered through the operation of a pair of hydraulic boom motors having a bucket attached to the arms thereof for being rocked about an axis of connection by a hydraulic bucket motor. A control system includes manual controls for controlling operation of the boom and bucket motors. The control system also includes a speech recognition device that is programmed for recognizing the speech of authorized operators and for sending signals responsive to certain command words for effecting desired control of the boom and bucket motors.