Vehicle Grade Severity Detection Using Motor Torque and Acceleration
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Solution Overview
Problem
Electric vehicles face challenges in maintaining safe and manageable speeds on inclined planes due to the limitations of existing motor control systems, particularly when traveling downhill, where regenerative braking is ineffective with a full battery, and inertial measurement units (IMUs) and tilt sensors (TS) suffer from latency issues, leading to potential runaway conditions.
Innovation Solution
A method using motor torque and motor acceleration to rapidly detect severe grades by estimating pitch through simplified calculations, allowing for faster speed reduction through motor control, reducing the reliance on IMUs and TS, and employing a controller to adjust speed based on torque and acceleration data with factors K1 and K2 for accurate grade severity detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If IMUs and tilt sensors are used to detect grade severity, then measurement capability is provided, but latency causes delayed response leading to potential runaway conditions
Solution Approach 1:
The patent replaces mechanical sensing systems (IMUs and tilt sensors) with an electrical/electronic detection method that uses motor control system data (current, voltage, speed, acceleration) to calculate pitch angle. This substitution eliminates the latency inherent in mechanical sensing while providing continuous real-time grade severity detection through the existing motor control infrastructure.
2Use of energy by moving object
If regenerative braking is used for speed control downhill, then energy recovery is achieved, but it is ineffective when battery is full
Solution Approach 1:
The patent enables the motor to serve dual functions: propulsion during acceleration and regenerative braking during deceleration. By detecting severe grade conditions through electrical parameter analysis and automatically commanding the motor to operate in regenerative braking mode, the system ensures continuous speed control capability regardless of battery charge state, with the motor self-adjusting its function based on real-time conditions.
3Ease of operation
If traditional motor control systems are used, then basic speed control is provided, but they lack the capability to rapidly detect and respond to severe grades
Solution Approach 1:
The patent continuously monitors electrical parameters (current, voltage, speed, acceleration) and pre-calculates pitch angle using the formula θ = arcsin((a*g)/v) before severe grade conditions fully develop. This preliminary detection and calculation enable the system to anticipate and respond to grade changes before they become critical, providing faster response than waiting for mechanical sensors to detect the condition.
Data Source
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AI summary
An apparatus for grade severity detection in a motorized vehicle includes a first sensor and a second sensor that provides data to a controller. The first sensor is configured to generate motion data indicative of at least one wheel of the motorized vehicle. The second sensor generate data, which is indicative of torque for at least one wheel of the motorized vehicle. The controller is configured to calculate a pitch of the motorized vehicle based on the torque data and one or more acceleration values derived from the position data and configured to perform a comparison of the calculated pitch to a pitch threshold. A grade severity message is generated based on the comparison.