Solenoid Valve Parameterization via Vehicle Dynamics
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Solution Overview
Problem
Existing brake systems with magnet control valves face challenges in accurately parameterizing switching parameters, especially when pressure sensors are absent, leading to imprecise activation and potential asymmetrical braking due to manufacturing tolerances and environmental factors.
Innovation Solution
A method to teach switching parameters of solenoid control valves by analyzing driving dynamics changes during test braking operations using existing vehicle sensors, such as speed and longitudinal acceleration sensors, without relying on pressure sensors, allowing for reliable parameterization and adjustment of switching parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If switching parameters of solenoid control valves are parameterized at the end of the assembly line, then manufacturing tolerances of the valves can be compensated, but tolerances in the vehicle's brake system (piping, brake cylinder volumes) cannot be taken into account and therefore cannot be compensated
Solution Approach 1:
The patent applies preliminary action by performing test braking operations and determining switching parameters before the brake system is put into service. The control device carries out test braking operations with initially stored switching parameters, evaluates the vehicle dynamics changes, and determines optimized switching parameters for each solenoid control valve based on the actual brake system characteristics of the specific vehicle, thereby compensating for both valve manufacturing tolerances and system-level tolerances in advance.
Solution Approach 2:
The patent implements feedback by using existing vehicle sensors (speed sensors, longitudinal acceleration sensors) to detect the actual vehicle dynamics during test braking operations. The control device evaluates these sensor signals to determine how the brake system actually responds to solenoid valve activation, and uses this feedback information to calculate optimized switching parameters that account for the specific vehicle's brake system characteristics.
2Measurement precision
If a pressure sensor is provided on the modulator to measure actual brake pressure, then pulse durations can be adjusted and tolerances can be compensated, but if such a pressure sensor is not present, the relearning process cannot be carried out since the brake pressure actually controlled is not known
Solution Approach 1:
The patent uses vehicle dynamics parameters (speed, longitudinal acceleration) as intermediary measurements to indirectly determine brake pressure effects. Instead of directly measuring brake pressure with a pressure sensor, the control device measures the vehicle's response to brake activation using existing sensors, and infers the switching parameters from these indirect measurements of vehicle dynamics changes.
Solution Approach 2:
The patent enables the brake system to perform its own parameterization using existing vehicle sensors and the vehicle's own dynamic response. The control device utilizes sensors already present in the vehicle (speed sensors, acceleration sensors) to carry out the learning process, making the system self-sufficient without requiring additional pressure sensors or external measurement equipment.
3Adaptability or versatility
If test braking operations are carried out while the vehicle is in motion to determine response pressure, then switching parameters can be adapted, but the method requires comparing vehicle accelerations before and after test braking which complicates the measurement process
Solution Approach 1:
The patent applies preliminary action by storing initial switching parameters before test braking operations and using these stored values as a baseline for comparison. The control device carries out test braking operations with the initially stored switching parameters, evaluates the vehicle dynamics changes against these known initial values, and determines optimized switching parameters based on this comparison, simplifying the measurement process.
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
This method enables precise adjustment of switching parameters for solenoid control valves, ensuring accurate and symmetrical braking performance without the need for pressure sensors, thereby improving braking system reliability and efficiency.
Implementation Method 1
Solenoid control valves, via which brake pressure can be built up in the respective brake cylinder as a function of a control signal
Data Source
Figure 1
Figure 2a~2b
Figure 3a~3b
AI summary
The invention relates to a method for teaching switching parameters of a solenoid control valve (9a, 9b, 10a, 10b) in a braking system (1) of a vehicle (3), comprising at least the following steps: defining a vehicle test acceleration; determining at least two test pulse sequences (PF1, PF2), each test pulse sequence (PF1, PF2) being determined in accordance with the defined vehicle test acceleration and in accordance with switching-parameter initial values for the solenoid control valve (9a, 9b, 10a, 10b) in question and the test pulse sequences (PF1, PF2) comprising actuation pulses and non-actuation pulses, activation of the solenoid control valve in question occurring during an actuation pulse and deactivation of the solenoid control valve (9a, 9b, 10a, 10b) in question occurring during a non-actuation pulse; controlling the solenoid control valve (9a, 9b, 10a, 10b) by means of the at least two test pulse sequences (PF1, PF2) in order to effect at least two test braking operations, a change in a brake pressure (pBa, pBb) at a service brake (5a, 5b) of the braking system (1) being effected by each test pulse sequence (PF1, PF2) in such a way that a change in the driving dynamics (w1, w2) of the vehicle (3) results; determining driving-dynamics change variables in order to determine the change in the driving dynamics (w1, w2) of the vehicle (3) resulting from the control with the corresponding test pulse sequence (PF1, PF2); and adjusting the switching-parameter initial values for the solenoid control valve (9a, 9b, 10a, 10b) in accordance with the driving-dynamics change variables in order to teach the switching parameters of the solenoid control valve (9a, 9b, 10a, 10b).