Work Vehicle Pitching Oscillation Damping via Speed Control
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Solution Overview
Problem
Existing agricultural and working vehicles experience disruptive pitching vibrations due to resilient tire suspension and height adjustments, affecting operational accuracy and comfort, with prior solutions either limited in damping effectiveness or only addressing speed changes during hopping movements.
Innovation Solution
An arrangement that detects pitching vibrations using sensors and controls the propulsion speed of the vehicle through an actuator to dampen oscillations, employing both open-loop and closed-loop control systems to maintain a stable position of attached elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the working vehicle uses resilient tire suspension for ground support, then the vehicle can adapt to uneven terrain and improve comfort, but pitching vibrations are generated during speed changes and height adjustments that disrupt operation
Solution Approach 1:
The control circuit receives actual position feedback from sensors monitoring the adjustable element's position and compares it with the target position. Based on this feedback, the control circuit generates control signals to actuate height adjustment mechanisms, continuously correcting the element's position to maintain desired cutting height despite pitching vibrations from resilient tire suspension
Solution Approach 2:
The system anticipates pitching vibrations that will occur during speed changes or height adjustments and pre-adjusts the position of the adjustable element before the vibration occurs. This preliminary action compensates for the expected disturbance, preventing the vibration from affecting operational accuracy
2Adaptability or versatility
If the height of an adjustable element is changed during operation, then the element can be repositioned to adapt to different working conditions, but pitching vibrations are excited that disrupt the stability of the system
Solution Approach 1:
Before changing the height of the adjustable element, the control system predicts the resulting pitching vibration and pre-adjusts the element's position or triggers compensatory actions in opposite-direction height adjustment mechanisms. This preliminary compensation prevents the vibration from destabilizing the system during the height change operation
Solution Approach 2:
The system uses opposite-direction height adjustment mechanisms that act as counterweights to compensate for pitching vibrations generated during height changes. When one element is adjusted upward, the counteracting mechanism adjusts another element downward to balance the system and prevent vibration-induced instability
3Productivity
If the working vehicle changes driving speed to respond to operator input or automatic control, then the vehicle can adapt to varying work requirements, but pitching vibrations are generated that affect operational precision
Solution Approach 1:
When the control system detects an upcoming speed change from operator input or automatic control, it anticipates the resulting pitching vibration and pre-adjusts the height of the adjustable element before the speed change occurs. This preliminary adjustment ensures that cutting height precision is maintained despite the subsequent vibration from speed variation
Solution Approach 2:
Sensors continuously monitor the actual position of the adjustable element and provide feedback to the control circuit. When speed changes cause pitching vibrations that deviate the element from its target position, the feedback loop detects this deviation and triggers corrective height adjustments to restore precision cutting height
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively reduces or eliminates pitching vibrations, maintaining the accuracy of height adjustments and improving operator comfort by controlling vehicle speed to counteract anticipated and existing oscillations.
Implementation Method 1
a sensor for detecting the respective position of the adjustable element
Implementation Method 2
the working vehicle is supported on the ground by air-filled (and thus resilient) tires and/or can be provided with a suspension between the wheels or caterpillar tracks and the body
Implementation Method 3
the signal from which is used to feed back the actual position of the element to a control circuit
Data Source
Figure 1
Figure 2~3
AI summary
An arrangement for damping a possible pitching oscillation of a work vehicle (10) supported on the ground by spring elements is provided with means for detecting an expected and/or existing pitching oscillation of the work vehicle (10) and a control device (42) which is connected to the means and an actuator for influencing the propulsion speed of the work vehicle (10) and is operable to control the actuator in the sense of damping the pitching oscillation.