Articulated Arm Return Control With Constant Vehicle Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The actuation speed of hydraulic members in work or agricultural vehicles is dependent on the vehicle speed, which limits productivity during operations like loading, moving, and unloading.
Innovation Solution
Implementing a control method that increases the rotation speed of the prime mover and adjusts the hydrostat to maintain vehicle speed independent of the prime mover speed, when activating functions like Return to DIG, Return to Travel, Return to Height, and Floating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the rotation speed of the prime mover is increased to increase hydraulic oil flow and arm actuation speed, then the productivity is improved, but the vehicle speed increases which may affect operational stability
Solution Approach 1:
The hydraulic system is segmented into two independent circuits: a first hydraulic circuit for vehicle propulsion and a second hydraulic circuit for work unit actuation. Each circuit has its own hydraulic pump, allowing independent control of vehicle speed and arm actuation speed. This segmentation resolves the contradiction by enabling the prime mover to increase rotation speed for faster arm operation without necessarily increasing vehicle speed, as the work hydraulic pump can be independently controlled.
2Stability of the object's composition
If the vehicle speed is maintained constant while increasing prime mover rotation speed for faster hydraulic actuation, then the operational stability is preserved, but the energy consumption increases
Solution Approach 1:
The system dynamically adjusts the rotation speed of the prime mover and the displacement of the hydrostat based on operational requirements. When return functions are activated, the prime mover speed is temporarily increased to provide sufficient hydraulic flow for rapid arm repositioning, while the hydrostat displacement is adjusted to maintain constant vehicle speed. This dynamic control allows the system to optimize energy consumption by only increasing prime mover speed when necessary for work unit actuation, not during continuous vehicle operation.
3Device complexity
If a single hydraulic circuit is used for both propulsion and work units, then the system complexity is reduced, but the actuation speed of hydraulic members is limited by vehicle speed
Solution Approach 1:
The hydraulic system is divided into two separate circuits: a first hydraulic circuit connected to the prime mover for vehicle propulsion, and a second hydraulic circuit with its own hydraulic pump for work unit actuation. This segmentation allows the work hydraulic pump to be driven at optimal speeds independent of vehicle speed, enabling faster arm actuation during loading, moving, and unloading operations without being constrained by the vehicle's travel speed requirements.
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
This approach allows for increased hydraulic oil flow, enhancing the speed of arm handling operations and improving overall productivity without affecting vehicle speed.
Implementation Method 1
The hydraulic circuit is powered by a hydraulic pump driven in rotation by a prime mover
Implementation Method 2
The vehicle transmission is generally composed of a hydrostat, which comprises a variable displacement hydraulic pump, which supplies a hydraulic motor connected directly or indirectly to a vehicle wheel with hydraulic oil
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method of performing a return function of an articulated arm (AB) of a work or agricultural vehicle (VEH), the return function comprising a procedure of moving the arm from any configuration to a pre-stored configuration. The vehicle is equipped with a prime mover (E), an electro-hydraulic circuit (HC) comprising two or more hydraulic actuators (A1, A2) serving the articulated arm, respective open center directional valves (V1, V2) and a pump hydraulic (P) power supply of the electro-hydraulic circuit, with fixed displacement, operatively connected to the prime mover to be driven in rotation. Furthermore, the vehicle comprises a transmission comprising a hydrostat (HY) comprising a hydraulic pump (HP) and a hydraulic motor (HM) hydraulically connected to the hydraulic pump and arranged to drive in rotation a vehicular wheel (W) and an accelerator pedal (AP) arranged to control a rotation speed of the prime mover. The method, in response to an activation of the feedback function, comprising a step of increasing the rotational speed of the prime mover and a simultaneous step of adapting a configuration of the hydrostat so as to maintain unchanged a current speed of the vehicle.