Sensor Bus Time-Division Multiplexing for Power Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensor systems for driver assistance, such as parking assistance, face challenges with high power consumption, increased costs, and complexity due to multiple sensors connected via separate data lines, and require precise time measurement for accurate echo propagation time calculation, which is not efficiently addressed by existing cost-effective solutions.
Innovation Solution
A sensor system utilizing a bus for data transmission with RC elements as time-measuring means, calibrated by control pulses for precise time measurement, allowing for reduced power consumption and simplified data traffic by sending only evaluation results, and enabling selective control of sensors for reduced hardware effort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors emit ultrasonic pulses at the same time to achieve highest measurement resolution, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic time-division multiplexing where sensors are activated in sequential time slots rather than simultaneously. Each sensor emits ultrasonic pulses periodically according to its assigned time slot, allowing measurement resolution to be maintained through repeated measurements while significantly reducing instantaneous power consumption by ensuring only one sensor is active at any given moment.
2Measurement precision
If each sensor is connected to the control unit via a separate data line for real-time data transmission, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent merges multiple separate data transmission lines into a single shared bus system. All sensors connect to the control unit through this common bus, and data transmission is organized through time-division multiplexing where each sensor is granted access to the bus in its assigned time slot. This consolidation dramatically reduces the number of physical connections required while maintaining real-time data transmission capabilities through coordinated access control.
3Ease of operation
If a fixed synchronization pulse with predefined width is used for bus communication, then ease of operation is improved, but measurement precision deteriorates
Solution Approach 1:
The patent performs preliminary calibration of the synchronization pulse width specifically for time-of-flight measurements. Instead of using a generic fixed-width synchronization pulse, the system pre-determines the optimal pulse width that satisfies both bus communication requirements and the precise time measurement needs of the ultrasonic sensors. This calibration is performed in advance to establish the correct timing parameters before actual measurements begin.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The invention provides a sensor system (1) comprising a bus (3) and at least one first sensor (2) with chronometric means (7), wherein the first sensor (2) is connected to further sensors (2) via the bus (3) and is set up to use a control pulse received via the bus (3) to measure an interval of time using the chronometric means (7). The invention also proposes a sensor (2) for use in a sensor system (1) described above.