Adaptive Tachograph Communication Timing
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Solution Overview
Problem
Tachograph systems in motor vehicles face inefficiencies due to standardized waiting times between commands, which do not account for varying processing speeds of different speed sensors, leading to potential overloading and prolonged diagnosis times.
Innovation Solution
The recording unit dynamically adjusts its waiting time between commands based on specific request data from the speed sensor, allowing for adaptive communication that optimizes communication efficiency by querying the minimum pause duration required by each speed sensor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a standardized waiting time of 25 seconds is used between commands to ensure compatibility with the slowest speed sensor, then all speed sensors can be accommodated without overloading, but the communication efficiency is reduced and diagnosis time is prolonged
Solution Approach 1:
The patent applies dynamics by making the waiting time between commands adaptive rather than fixed. The recording unit dynamically adjusts the waiting time based on the actual processing speed of each speed sensor. This is achieved by having the recording unit send a query command to determine the required pause duration, then adjust subsequent command timing accordingly. This dynamic adjustment resolves the contradiction by allowing fast speed sensors to communicate with shorter waiting times (improving productivity) while still accommodating slower sensors when needed (maintaining reliability).
Solution Approach 2:
The patent changes the parameter of waiting time from a fixed standardized value (25 seconds) to a variable value determined by the specific speed sensor's capabilities. The recording unit queries the speed sensor to obtain the required pause duration parameter, then uses this parameter to adjust the timing of subsequent commands. This parameter change enables the system to optimize communication speed for each individual speed sensor while maintaining compatibility across different technologies.
2Reliability
If a large waiting time value is set to accommodate the slowest speed sensor technology, then the speed sensor is not overloaded, but the potential of faster speed sensors is left untapped
Solution Approach 1:
The patent applies preliminary action by having the recording unit send a query command before the actual data commands to determine the required pause duration. This preliminary query allows the recording unit to know in advance how long to wait between commands for that specific speed sensor. By performing this preliminary determination, the system avoids using unnecessarily long waiting times (reducing diagnosis time) while ensuring the speed sensor is not overloaded (maintaining protection).
Solution Approach 2:
The patent uses feedback by having the speed sensor provide information about its required pause duration in response to the query command. The recording unit receives this feedback and adjusts its command timing accordingly. This feedback mechanism enables the system to adapt to the actual capabilities of each speed sensor, preventing overloading while maximizing communication speed and minimizing diagnosis time.
Data Source
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AI summary
The invention relates to a method for controlling communication (20) between a recording unit (12) and a speed sensor (13) of a tachograph system (11) of a motor vehicle (10), wherein the recording unit (12) repeatedly sends a command (18) to the speed sensor (13) and receives response data (19) to the command (18) from the speed sensor (13), wherein the recording unit (12) waits a predetermined waiting time (26) between sending successive commands (18).The invention provides that the recording unit (12) sends a query command (27) to the speed sensor (13) before sending the first of the commands (18), wherein the query command (27) requests the minimum pause duration (29) required by the speed sensor (13) between two commands (18), and if the speed sensor (13) provides time duration data (28) relating to the pause duration (29) in response to the query command (27), the recording unit (12) sets the respective waiting time (26) depending on the time duration data (28).