Loader

Abstract

A loader including a vehicle including a structural frame and an elongate boom arm is provided. The boom arm is pivotally mounted at its first end to the frame and has at its second end an assembly for receiving a tool. The loader includes actuators to actuate the boom arm and its associated assembly. The loader also includes a control unit provided with user operable controls for controlling position and orientation of the boom arm and its associated assembly. The actuators integrally incorporate therein magnetic sensors operable to sense longitudinal extension of the actuators and thereby generate actuator feedback signals indicative of the longitudinal extension. The control unit processes the actuator feedback signals in a feedback control to render the position and orientation of the boom arm and its associated assembly adjustable using the user operable controls. Sensing a rotation rate of vehicle engine providing power to the actuators is employed to modify the feedback control to improve operating stability of the loader.

1 . A loader comprising a vehicle including a structural frame and at least one elongate boom arm, the at least one elongate boom arm being pivotally mounted substantially at its first end to the structural frame and having at its second end an assembly for receiving in operation one or more tools, the loader further including actuators operable to actuate the at least one boom arm and its associated assembly, and also including a control unit provided with user operable controls for controlling in operation position and orientation of the at least one boom arm and its associated assembly, wherein the actuators integrally incorporate therein magnetic actuator sensors operable to sense longitudinal extension of the actuators and thereby generate actuator feedback signals indicative of the longitudinal extension, wherein the control unit is operable to process the actuator feedback signals in a feedback control to render the position and orientation of the at least one boom arm and its associated assembly adjustable using the user operable controls. 
   
   
       2 . A loader as claimed in  claim 1 , wherein the magnetic actuator sensors integrally included within the actuators are each operable to sense relative positions of a piston and its associated co-operating cylinder of its corresponding actuator. 
   
   
       3 . A loader as claimed in  claim 1 , wherein the actuators include a first actuator operable to actuate the at least one boom arm to vary its pivotal angle relative to the structural frame, and a second actuator operable to actuate the assembly to vary its pivotal angle relative to substantially the second end of the at least one boom arm. 
   
   
       4 . A loader as claimed in  claim 1 , wherein the control unit is operable to apply a mathematic translation to the actuator feedback signals to generate translated signals indicative of an inclination angle of the one or more tools and a height of the one or more tools, the translated signals being compared in the control unit with signals from the user operable controls to provide in operation the feedback control. 
   
   
       5 . A loader as claimed in  claim 1 , wherein the feedback signals are operable to provide substantially a first order dynamic measure of angular orientations of the at least one boom arm and its associated assembly and one or more tools. 
   
   
       6 . A loader as claimed in  claim 1 , wherein the control unit is operable to enable the user:
 (a) to record one or more sets of preferred angular orientations of at least one boom arm and its associated assembly corresponding to preferred positions and orientations of the one or more tools, and   (b) to invoke the one or more sets of orientations for operating the one or more tools for moving them to one or more of the preferred positions.   
   
   
       7 . A loader as claimed in  claim 1 , wherein the vehicle includes an inertial sensing unit for sensing at least one of inclination, acceleration, deceleration and vibration of the vehicle and thereby generating an inertial signal, the sensing unit being in communication with the control unit for receiving the inertial signal such that the control unit is operable to modify at least one of angular orientation and height of the one or more tools in response to the inertial signal for retaining a load borne in operation by the one or more tools more securely. 
   
   
       8 . A loader as claimed in  claim 1 , wherein the vehicle comprises an engine operable to provide actuation power for the actuators, the engine including an engine rotation rate sensor adapted to generate a rotation rate signal indicative of a rotation rate of the engine in operation, wherein the control unit is arranged to receive the rotation rate signal for adapting the feedback control in response to the rotation rate signal. 
   
   
       9 . A control system including a control unit adapted to control operation of a loader, the loader comprising a vehicle including a structural frame and at least one elongate boom arm, the at least one elongate boom arm being pivotally mounted substantially at its first end to the structural frame and having at its second end an assembly for receiving in operation one or more tools, the system further including actuators operable to actuate the at least one boom arm and its associated assembly, and also including the control unit provided with user operable controls for controlling in operation position and orientation of the at least one boom arm and its associated assembly, wherein the actuators integrally incorporate therein magnetic actuator sensors operable to sense longitudinal extension of the actuators and thereby generate actuator feedback signals indicative of the longitudinal extension, wherein the control unit is operable to process the actuator feedback signals in a feedback control to render the position and orientation of the at least one boom arm and its associated assembly adjustable using the user operable controls. 
   
   
       10 . A control system as claimed in  claim 9 , wherein the magnetic actuator sensors are each operable to sense relative positions of a piston and its associated co-operating cylinder of its corresponding actuator. 
   
   
       11 . A method of controlling operation of a loader, the loader comprising a vehicle including a structural frame and at least one elongate boom arm, the at least one elongate boom arm being pivotally mounted substantially at its first end to the structural frame and having at its second end an assembly for receiving in operation one or more tools, the loader further including actuators operable to actuate the at least one boom arm and its associated assembly, and also including the control unit provided with user operable controls for controlling in operation position and orientation of the at least one boom arm and its associated assembly, wherein magnetic actuator sensors operable to sense longitudinal extension of the actuators are integrally incorporating in the actuators, the method comprising steps of:
 (a) generating actuator feedback signals indicative of the longitudinal extension;   (b) processing the actuator feedback signals in the control unit to implement a feedback control to render the position and orientation of the at least one boom arm ( 40 ) and its associated assembly adjustable using the user operable controls.   
   
   
       12 . A method as claimed in  claim 11 , wherein the magnetic actuator sensors are each operable to sense relative positions of a piston and its associated co-operating cylinder of its corresponding actuator. 
   
   
       13 . A method as claimed in  claim 11 , wherein step (b) further comprises steps of:
 (c) applying a mathematical translation to the actuator feedback signals to generate translated signals indicative of an inclination angle of the one or more tools and a height of the one or more tools; and   (d) comparing the translated signals in the control unit with signals from the user operable controls to provide in operation the feedback control.   
   
   
       14 . A method as claimed in  claim 11 , wherein the feedback signals are operable to provide substantially a first order dynamic measure of angular orientations of the at least one boom arm and its associated assembly and one or more tools. 
   
   
       15 . A method as claimed in  claim 11 , wherein the method includes further steps of:
 (e) measuring using a rotation rate sensor a rotation rate of an engine of the vehicle and generating a corresponding rotation rate signal; and   (f) adapting the feedback control in response to the rotation rate signal to enhance stability of the feedback control.   
   
   
       16 . Software on a data carrier executable on computing hardware of a control unit of a loader for implementing the method as claimed in  claim 11 .