摘要:
An apparatus and method for calibrating a PTO for driving a cutter of a header of an agricultural windrower, wherein a programmable control module in connection with at least signal operated device in operative control of a variable displacement pump operable for controlling operation of the PTO, is programmed as part of an automatic calibration routine for directing signals to the device having values which will increase over time from a first value toward a second value. At the same time, the control module determines when a first movement of the cutter occurs. If the first movement occurs before the second signal value is reached, information representative of an electrical signal corresponding to the first movement is stored. The routine is then repeated using a higher range of electrical signal values to calibrate where the cutter reaches max speed. In either instance, if the speed condition is not reached with the outputting of the signals within the range, the calibration fails.
摘要:
An apparatus and method for varying the speed of a reel versus ground speed of an agricultural windrower, wherein a programmable control module in connection with a signal operated device operable for controlling operation of the reel, is programmed to operate in an automatic mode to control the reel speed as a percentage of the ground speed, while preventing the reel speed from falling below a minimum value.
摘要:
An apparatus and method for calibrating the reel of an agricultural windrower, wherein a programmable control module in connection with a signal operated device in operative control of a variable displacement pump operable for controlling operation of the reel, is programmed as part of an automatic calibration routine for directing signals to the device having different values, for rotating the reel at two different speeds. The controller will then determine a characteristic algorithm or relationship between reel speed and signal value which will be predictive of reel speeds which will be achieved for a range of signal values.
摘要:
A metal detector comprises a detection coil disposed in a magnetic field, the ends of the coil being connected through a balanced resistor network to the inputs of a differential amplifier. A test signal is injected into the metal detector at a point such that the coil is effectively in series with one branch of the balanced resistor network. The injected signal produces a potential difference at the inputs of the differential amplifier, the magnitude of the potential difference being dependent on the resistance of the detection coil. The test signal is generated by a circuit including a microcomputer which successively feeds digital values corresponding to the sine function to a digital-to-analog converter, so that the converter generates the test signal in the form of a sine wave. The output signal from the differential amplifier is applied to an analog-to-digital converter. The microcomputer controls the analog-to-digital converter to repetitively sample the output signal from the amplifier and convert each sample to a digital value. The digital values are compared with two threshold values corresponding to the maximum and minimum values the amplifier output signal may have when the coil resistance is within an acceptable range and when the amplifier output signal exceeds the maximum or is less than the minimum value an error indication is produced.
摘要:
In a two-channel magnetic metal detector for a forage harvester, positive and negative adaptive detection thresholds are varied according to long term changes in the noise component induced in detection coils by moving ferrous parts of the crop feed mechanism. The adaptive detection thresholds are set at levels determined by the positive and negative peak averages of the noise components in the channels while the crop feed mechanism is running at normal speed. Start-up transient noise induced in the detection coil as the crop feed mechanism accelerates may exceed the adaptive thresholds as thus set, thereby triggering false indications that a tramp metal object has been detected in the crop feed path. At start-up of the crop feed mechanism, the detection thresholds are raised to prevent false indications. An increase in a channel noise signal is taken as an indication that the crop feed mechanism is accelerating. The detection thresholds are then raised to a level above any transient noise level expected during acceleration of the crop feed mechanism. After a predetermined time sufficient for the feed mechanism to reach normal operating speed, the detection thresholds are set at their adaptive detection levels.
摘要:
The metal detector circuitry for a forage harvester is provided with a socket for receiving a pluggable unit, the arrangement being such that a resistor in the pluggable unit is connected into the detection circuitry of a metal detector whereby the sensitivity of the metal detector may be changed by inserting into the socket a pluggable unit containing a resistor of a different value. A metal detector test assembly connected to the metal detector through the socket, provides a means for testing the sensitivity of the metal detector and its associated circuitry. The test assembly includes a signal unit which is placed adjacent the metal detector sensing unit and generates a magnetic field that is sensed by the sensing unit, and a test box with circuitry, indicators and switches for selectively checking the sensitivity of the metal detector and correct operation of its associated circuitry.
摘要:
An off-road work vehicle has a steer-by-wire steering system having a device for determining the angular displacement of a steering wheel. The device has a cam configured to rotate about an axis at an identical angular speed as the steering wheel, a first sensor proximal to a facing outer surface of the cam and being configured to determine a distance between the first sensor and the facing outer surface of the cam, a second sensor proximal to a facing outer surface of the cam and being configured to determine a distance between the second sensor and the facing outer surface of the cam, and a processor operably connected with the first and second sensors and configured to determine an angular position of the steering wheel and a direction of rotation of the steering wheel based upon data generated by the first and/or the second sensor. The distance between each of the first and second sensors and the facing outer surface of the cam changes gradually over a first major portion of the facing outer surface and sharply over a second, minor portion of the facing outer surface. The two sensors are redundant to one another and help maintain the robustness of the system.
摘要:
A system and method for calibrating a header flotation system of an agricultural vehicle that can be employed while the vehicle is in motion, including when traversing a field, which does not rely on, or require calibration of, height and/or pressure sensors.
摘要:
In a forage harvester, a shear bar is adjusted relative to the knives of a rotating cutterhead by selectively energizing first and second motors to move one or the other end of the shear bar toward the cutterhead. A vibration sensor senses vibration of the shear bar and controls a circuit to deenergize an energized motor when vibration is induced in the shear bar. The vibration may be caused by impact of the cutterhead knives on the shear bar (a true hit) or by random noise (detected as a false hit). To discriminate between false hits and true hits, an energized motor is stopped when a first hit (true or false) is detected. A timer is set to time an interval at least as great as the time it takes the cutterhead to make one revolution, and during this interval the vibration sensor is repeatedly sampled to determine if a second hit has occurred. If a second hit is detected during the interval the first hit is assumed to be a true hit. If a second hit is not detected during the interval then the first hit is assumed to be a false hit and the deenergized motor is restarted.
摘要:
A potentiometer is driven by one of the serpentine arm assemblies used to maintain apron tension during formation of a round bale so that the output of the potentiometer continuously provides an indication of the size of a bale being formed in the baler. A microprocessor based control circuit senses the output of the potentiometer, converts it to a digital value, and compares the digital value with a value representing a desired bale size. When the two values are equal, the microprocessor computes the number of revolutions of a net feed roll that is required to wrap the bale a preselected number of times, energizes the net feed roll mechanism to feed net into the bale forming chamber, and counts the revolutions of the net feed roll. When the required amount of net has been dispensed, the microprocessor stops the net feed roll and activates a mechanism to cut the net. The size of a "full bale" is selected by actuating keys on a control panel. An offset is automatically provided to compensate for wear in the apron mechanism affecting the "zero" setting of the bale size sensor. The system permits signalling the operator to steer left or right along a windrow to control bale shape as the bale being formed in the chamber increases in diameter, the signalling rate being non-linear with respect to bale diameter.