Vehicle Hatch Motor Control Using Current Variation Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for detecting movement initiated by external forces on vehicle hatches or actuatable objects require additional hardware for back-EMF monitoring and struggle with low back-EMF detection in small or slow movements.
Innovation Solution
A method involving applying a first voltage level lower than the threshold for rotor movement, monitoring current variations, and applying a second higher voltage level when pre-determined criteria are met, along with a control circuit and actuator module to manage hatch movement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If back-EMF monitoring is used to detect external forces on the hatch, then movement detection capability is improved, but additional hardware is required
Solution Approach 1:
The patent replaces the mechanical/electromagnetic back-EMF monitoring system with an electrical current monitoring system. By monitoring current variations through the electromotor windings while applying a first voltage level, the system detects external forces without requiring additional back-EMF sensing hardware. The current variations caused by external forces acting on the rotor are evaluated to determine when to apply the second voltage level for hatch movement.
2Measurement precision
If back-EMF monitoring is used to detect movement, then detection accuracy is improved, but the method fails for small or slow movements due to low back-EMF signal
Solution Approach 1:
The patent changes the monitoring parameter from back-EMF voltage to current variations. By monitoring current through the windings while applying a first voltage level, the system can detect even small current variations caused by external forces acting on the rotor, regardless of the speed or magnitude of movement. This current-based detection method provides reliable detection for both small and slow movements that would produce insufficient back-EMF signals.
3Speed
If high voltage is applied to move the rotor quickly, then movement speed is improved, but energy consumption increases
Solution Approach 1:
The patent implements a dynamic voltage control system that adjusts the voltage level applied to the electromotor based on real-time detection of external forces. The system applies the first voltage level (lower energy consumption) during normal operation and only switches to the second voltage level (higher speed capability) when external forces are detected and hatch movement is required. This dynamic adjustment optimizes the balance between movement speed and energy consumption.
4Stability of the object's composition
If standby voltage is applied to prevent rotor movement, then position stability is improved, but current flow increases energy consumption
Solution Approach 1:
The patent optimizes the standby voltage parameter to achieve position stability with minimal energy consumption. By carefully selecting the first voltage level that generates sufficient electromagnetic force to counteract external forces and maintain rotor position, while remaining below the threshold for rotor movement, the system achieves stable positioning. The associated current consumption at this optimized voltage level is minimized, reducing standby energy consumption compared to conventional approaches.
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
Accurately detects and responds to external forces on vehicle hatches with improved efficiency and reduced hardware requirements, ensuring precise control and energy conservation.
Implementation Method 1
a DC electromotor (200) having a rotor (210). The method comprises applying a first voltage (U1) having a first voltage level to windings of the electromotor (200). By applying a particular voltage to the electromotor, a magnetic force between rotor and stator may be created
Implementation Method 2
Monitoring the back-EMF (electromagnetic force) generally requires additional hardware for actuators. The supply or terminal voltage of an electromotor driving the flap is monitored, while the electromotor is not operated. If change in the voltage is detected, such is assumed to occur by virtue of an external force to be applied to the fuel door.
Data Source
Figure 1~2
Figure 3
AI summary
A method of controlling movement of a hatch of an inlet for energy supply of a motorised vehicle between a first hatch position in which the inlet is covered by the hatch and a second hatch position in which the inlet is accessible for providing energy to the motorised vehicle, the hatch being operatively connected to a rotor of a DC electromotor.. The method comprises applying a first voltage level to the windings of the electromotor, the first voltage level being lower than required for movement of the rotor, the application of the first voltage resulting a current having a first current to flow through the windings and monitor the current for one or more variations in the first current level. When the variations detected in the current satisfy a criterion, a second voltage is applied having a second voltage level that is higher than the threshold voltage level.