Vehicle Control Device for Sensor Abnormality Fail-Safe
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When an abnormality occurs in the shift position sensor, existing technologies cannot determine the N range or P range, leading to a failure in starting the vehicle, which prevents fail-safe running.
Innovation Solution
A control device that determines sensor abnormalities and allows vehicle starting based on specific conditions, such as braking force and shift signal patterns, to ensure safe operation even with sensor faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the shift position sensor is used to determine shift range, then the shift range can be accurately detected, but when sensor abnormality occurs, the vehicle cannot start and fail-safe running is prevented
Solution Approach 1:
The control device performs preliminary determination of sensor abnormality before allowing vehicle start. The determination unit checks whether the shift signal contains both vehicle-stop signal and vehicle non-stop signal, and the start control unit decides whether to allow starting based on this preliminary assessment and additional conditions (braking force, shift signal patterns), enabling fail-safe running capability
Solution Approach 2:
The control device introduces intermediary conditions (braking force threshold, shift signal pattern analysis, accelerator operation status) as mediators between the sensor abnormality detection and the vehicle start decision. These intermediaries provide additional verification layers to ensure safe starting even when the shift position sensor is abnormal
2Object-affected harmful factors
If the vehicle start is prohibited when sensor abnormality occurs, then safety is ensured, but fail-safe running ability is reduced
Solution Approach 1:
The control device dynamically adjusts the vehicle start decision based on real-time sensor signals and operational conditions. Instead of a fixed prohibition policy, the system continuously evaluates shift signals, braking force, and shift lever position to dynamically determine whether starting is safe, thereby enabling fail-safe running when conditions permit
Solution Approach 2:
The control device changes the decision parameters from a simple binary (allow/prohibit start) to a multi-parameter evaluation system including braking force magnitude, shift signal patterns, and shift lever position. By monitoring changes in these parameters over time, the system can safely allow starting under abnormal conditions while maintaining safety
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
An ECU (800) includes an abnormality determination unit (810), a stop assurance determination unit (820), and a system activation unit (830). During the deactivation of a driving system of a vehicle, the abnormality determination unit (810) determines whether or not a P range abnormality occurs which exhibits that a shift signal transmitted from a shift position sensor includes a P signal and an MJ signal corresponding to the P range as well as a different-type signal other than the P signal and the MJ signal. When the P range abnormality occurs, the stop assurance determination unit (820) determines whether or not the vehicle-stopped state can be assured based on whether or not a brake-ON state (a hydraulic braking force or a parking braking force are beyond the range capable of maintaining vehicle-stopped state) is present. In a case where a P range abnormality occurs, when the stop assurance determination unit (820) determines that the vehicle-stopped state can be assured, the system activation unit (830) allows the activation of the driving system.