| CPC B60L 3/0061 (2013.01) [G07C 5/008 (2013.01); G07C 5/0808 (2013.01); G07C 5/0816 (2013.01); B60L 2250/00 (2013.01)] | 5 Claims |
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1. A method for detecting rotary transformer performance based on data analysis, comprising:
S1: obtaining vehicle usage information during the period between two consecutive maintenance events from historical data for a vehicle under test; generating interference characteristics of a rotary transformer in the vehicle under test based on the vehicle usage information wherein the vehicle usage information includes a number of vehicle operations, temperature values of the rotary transformer at different times during each operation, and vibration state values during each operation;
S2: obtaining a status characteristics of the rotary transformer during each maintenance event of the vehicle under test, wherein the status characteristics include resistance values of an excitation winding, a sine winding, and a cosine winding; constructing a relationship function that reflects changes in winding variables with the vehicle operation time, the winding variables being maximum differences between the resistance values of the excitation winding, the sine winding, and the cosine winding, and their respective initial resistance values; analyzing a deviation between the constructed relationship function and corresponding relationship functions in a database for vehicles that have undergone rotary transformer replacement, thereby obtaining a set of related user vehicles for the vehicle under test;
S3: combining interference characteristics of the rotary transformer based on the vehicle usage information and a fluctuation range of resistance values corresponding to each winding of the rotary transformer, to obtain a bump open-circuit risk resistance variation for the vehicle under test; substituting the bump open-circuit risk resistance variation into the relationship function of winding variables with operation time for each related user vehicle in the set obtained in S2, wherein an average value of results for each operation time is recorded as an effective operation life of the rotary transformer in the vehicle under test; and
S4: using a total usage time of the rotary transformer in the vehicle under test from historical data and the effective operation life of the rotary transformer, calculating a fault risk impact value of the rotary transformer at a current time, when the current fault risk impact value is less than a risk threshold, generating a pre-warning message for rotary transformer replacement, and sending this message to a mobile terminal of a user associated with the vehicle under test via a wireless communication network,
wherein:
in the vehicle usage information, the vibration state values of the rotary transformer at different times are equal to monitoring results of the vibration sensor closest to the rotary transformer at a corresponding time,
wherein:
generating interference characteristics of the rotary transformer based on the vehicle usage information in S1 comprises the steps of:
S11: obtaining the vehicle usage information during a period between the i-th and the (i+1)-th maintenance events from historical data for the vehicle under test, denoted as A(i,i+1); recording the time interval of the j-th operation of the vehicle in A(i,i+1) as Bj(i,i+1), and the temperature value of the rotary transformer at time t in Bj(i,i+1) as Tt(i,i+1), and the vibration state value at time t in Bj(i,i+1) as Ztj(i,i+1), where t∈Bj(i,i+1);
S12: obtaining the interference impact value of the operating environment on the rotary transformer during the j-th operation of the vehicle under test, during the period between the i-th and the (i+1)-th maintenance events, denoted as Gj(i,i+1), wherein Gj(i,i+1)=∫t=t1t=t2F{Ttj(i,i+1),Tb}=Ztj(i,i+1)dt, t1 represents the minimum value in Bj(i,i+1), t2 represents the maximum value in Bj(i,i+1), and Tb is a preset temperature reference value in the database, when T(i,i+1)≥Tb, F{Ttj(i,i+1),Tb}=g×(Ttj(i,i+1)−Tb)+r, when Ttj(i,i+1)<Tb, {Tt(i,i+1),Tb}=g1×(Tb−Ttj(i,i+1))+r,
wherein g represents the first interference conversion coefficient, g1 represents the second interference conversion coefficient, and r represents the temperature interference threshold, with g, g1 and r being preset constants in the database;
S13: entering each interference impact value of the operating environment on the rotary transformer for different i and j values from historical data into an empty set, to obtain an interference impact set, selecting an element with the maximum interference impact value in the interference impact set as the interference characteristic of the rotary transformer based on the vehicle usage information for the vehicle under test,
wherein:
constructing the relationship function of winding variables with vehicle operation time in S2 comprises:
S201: obtaining the status characteristics of the rotary transformer during each maintenance event of the vehicle under test; and recording resistance values of the excitation winding, sine winding, and cosine winding during the i-th maintenance D[i]1, D[i]2, and D[i]3, respectively;
S202: constructing a winding variable data pair corresponding to the status characteristics of the rotary transformer during the i-th maintenance event of the vehicle under test, denoted as (STi, RBi), STi represents the operation time of the vehicle from most recent rotary transformer replacement to the i-th maintenance event, and RBi represents the winding variable value corresponding to the status characteristics of the rotary transformer during the i-th maintenance event, RBi=max{D[i]1−DM1, D[i]2−DM2, D[i]2−DM2}, max{ } denoting a function to obtain the maximum value, and DM1, DM2, and DM3 represent initial resistance values of the excitation winding, the sine winding, and the cosine winding, respectively, corresponding to the most recent rotary transformer replacement; and
S203: constructing a Cartesian coordinate system having an origin at o, the vehicle operation time as the x-axis, and winding variable values as the y-axis; plotting coordinates of the winding variable data pairs obtained in S202 for different values of i on the Cartesian plane; connecting adjacent coordinate points in ascending order of x-axis values to obtain a polyline chart representing the change in winding variable values with vehicle operation time, using the corresponding function of the polyline chart as the relationship function of winding variables with vehicle operation time, denoted as F(x), wherein a range of x is [0, xm], with xm representing a total operation time of the vehicle during a most recent maintenance event,
wherein:
obtaining the set of related user vehicles for the vehicle under test in S2 comprises:
S211: obtaining the relationship function of winding variables with vehicle operation time for user vehicles in the database that have undergone rotary transformer replacement, wherein a relationship function for the k-th user vehicle before the replacement is denoted as Fk(xk), wherein a range of xk is [0,xkm], with xkm representing the total operation time of the k-th user vehicle at the time of replacement, wherein the operation time refers to a duration during which the vehicle was in a running state;
S212: calculating a deviation state value between F(x) and Fk(xk), denoted as P[F(x),Fk(xk)], wherein P[F(x),Fk(xk)]{∫xL=0xL=min{xm,xkm}Fk(xL)−F(xL)dxL}/min{xm,xkm}, with min{ } representing the operation to obtain the minimum value, Fk(xL) denotes the result when xk equals xL in Fk(xk), and F(xL) denotes the result when x equals xL in F(x); and
S213: when P[F(x),Fk(xk)]≤β and xkm>xm, classifying the user vehicle corresponding to Fk(xk) as a related user vehicle for the vehicle under test, and β is a preset deviation state threshold in the database,
the set of all related user vehicles for the vehicle under test in the database is referred to as the related user vehicle set for the vehicle under test,
wherein:
obtaining the bump open-circuit risk resistance variation for the vehicle under test in S3 comprises: includes the following:
S301: obtaining the interference characteristics of the rotary transformer based on the vehicle usage information and the fluctuation range of resistance values corresponding to each winding, wherein the fluctuation range of resistance values for each winding of the rotary transformer corresponds to the normal operating resistance range for each winding, as preset in the database;
S302: obtaining the bump open-circuit risk resistance variation for the vehicle under test, denoted as min{a1, a2},
a1 represents the difference between the maximum resistance fluctuation value and the initial resistance value of the winding with the greatest difference from its initial resistance value at the current time, among the excitation winding resistance, the sine winding resistance, and the cosine winding resistance,
a2 represents the open-circuit impact resistance, wherein a2=b−h×c, with b representing the difference between the maximum winding resistance n before the rotary transformer replacement in historical data and the initial resistance value of the corresponding winding of the rotary transformer in the vehicle under test, h represents the bump interference resistance coefficient, and c represents the interference characteristics of the rotary transformer based on the vehicle usage information,
a value of h equals the average bump interference coefficient corresponding to each historical experimental data pair, with each experimental data pair corresponding to a bump interference coefficient,
each experimental data pair is denoted as (Ec, N), wherein different experimental data pairs have different Ec values, Ec represents the interference characteristics of the rotary transformer based on the vehicle usage information in the experimental data pair, W represents the winding corresponding to a1 of the rotary transformer operation at the time of replacement before the replacement in the historical data, represents the average resistance value of the winding type W after being influenced by interference characteristics Ec in the experiment wherein the coil of the winding type W breaks under the influence of interference characteristics Ec, and N<n, and
a bump interference coefficient corresponding to (Ec, N) is equal to (n−N)/Ec, and
wherein:
obtaining the fault risk impact value of the rotary transformer at the current time in S4 comprises:
S41: obtaining the total usage time SYT and an effective operational lifespan YYT of the rotary transformer in the vehicle under test from historical data; and
S42: calculating the fault risk impact value, denoted as GFY, where GFY=(YYT−SYT)/PYT, with PYT representing the average total operation time of the vehicle between consecutive maintenance events.
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