Techniques for calculating surface breakpoints for secondary safety verifications in vehicle controls systems
A calibration technique for a multi-dimensional surface for functional safety verification of a control system of a vehicle involves accessing a memory configured to store operation data relative to the control system of the vehicle, the operation data representing a multi-dimensional surface comprising a plurality of data points, identifying a plurality of breakpoints for representing the multi-dimensional surface based on a maximum allowable number of breakpoints, instantaneous data point slopes, and minimum/maximum breakpoint spacing constraints, and generating a calibrated look-up table for the control system, the calibrated look-up table including the plurality of breakpoints, wherein the calibrated look-up table is configured to be utilized for functional safety verification of an output of the control system.
1 . A calibration system for a multi-dimensional surface for functional safety verification of a control system of a vehicle, the calibration system comprising:
a memory configured to store operation data relative to the control system of the vehicle, the operation data representing a multi-dimensional surface comprising a plurality of data points;
a computer system configured to:
identify a plurality of breakpoints for representing the multi-dimensional surface based on a maximum allowable number of breakpoints, instantaneous data point slopes, and minimum/maximum breakpoint spacing constraints; and
generate a calibrated look-up table for the control system, the calibrated look-up table including the plurality of breakpoints, wherein the calibrated look-up table is configured to be utilized for functional safety verification of an output of the control system; and
the control system of the vehicle, wherein the control system is configured to:
receive, from the computer system, the calibrated look-up table and store the calibrated look-up table, wherein the calibrated look-up table requires less memory storage capacity than all possible outputs of a neural network model executable by the vehicle;
control operation of the vehicle including generating, based on the neural network model, the output; and
during the operation of the vehicle, utilize the calibrated look-up table to determine whether the output satisfies a functional safety verification.
2 . The calibration system of claim 1 , wherein:
the output is a primary output generated by the control system during the operation of the vehicle based on the neural network model; and
the control system is configured to determine whether the output satisfies the functional safety verification by generating a secondary output using the calibrated look-up table and determining whether the primary and secondary outputs are sufficiently similar,
wherein the use of the calibrated look-up table for the functional safety verification of the primary output reduces a processing load on the control system by eliminating a need for a secondary execution of the neural network model to obtain the secondary output.
3 . The calibration system of claim 1 , wherein the computer system is further configured to identify the plurality of breakpoints by (i) determining a minimum/maximum step and a slope deviation for identifying a breakpoint.
4 . The calibration system of claim 3 , wherein the computer system is further configured to identify the plurality of breakpoints by (ii) determining an instantaneous slope at a first data point and creating a line with the determined instantaneous slope through the first data point.
5 . The calibration system of claim 4 , wherein the computer system is further configured to identify the plurality of breakpoints by (iii) stepping to a second data point and comparing a Y-value of the second data point to a Y-value of the created line.
6 . The calibration system of claim 5 , wherein the computer system is further configured to identify the plurality of breakpoints by (iv) identifying the first data point as a breakpoint when the difference between the Y-values of the second data point and the created line is greater than the slope deviation.
7 . The calibration system of claim 6 , wherein the computer system is further configured to identify the plurality of breakpoints by continuing identifying breakpoints until the maximum number of breakpoints have been identified.
8 . The calibration system of claim 3 , wherein the multi-dimensional surface is a two-dimensional (2D) surface.
9 . The calibration system of claim 3 , wherein the multi-dimensional surface is a three-dimensional (3D) surface, and wherein the computer system is further configured to divide the 3D surface into a plurality of 2D surfaces.
10 . The calibration system of claim 9 , wherein the computer system is further configured to:
identify the plurality of breakpoints for each of the plurality of 2D surfaces; and
determine a plurality of breakpoints for the 3D surface by calculating a weighted sum of an average and a maximum of the plurality of breakpoints for the plurality of 2D surfaces, respectively.
11 . A calibration method for a multi-dimensional surface for functional safety verification of a control system of a vehicle, the calibration method comprising:
accessing, by a computer system, a memory configured to store operation data relative to the control system of the vehicle, the operation data representing a multi-dimensional surface comprising a plurality of data points;
identifying, by the computer system, a plurality of breakpoints for representing the multi-dimensional surface based on a maximum allowable number of breakpoints, instantaneous data point slopes, and minimum/maximum breakpoint spacing constraints;
generating, by the computer system, a calibrated look-up table for the control system, the calibrated look-up table including the plurality of breakpoints, wherein the calibrated look-up table is configured to be utilized for functional safety verification of an output of the control system;
receiving, by the control system of the vehicle and from the computer system, the calibrated look-up table and storing, by the control system, the calibrated look-up table, wherein the calibrated look-up table requires less memory storage capacity than all possible outputs of a neural network model executable by the vehicle;
controlling, by the control system, operation of the vehicle including generating, based on the neural network model, the output; and
during the operation of the vehicle, utilizing, by the control system, the calibrated look-up table to determine whether the output satisfies a functional safety verification.
12 . The calibration method of claim 11 , wherein:
the output is a primary output generated by the control system during the operation of the vehicle based on the neural network model; and
the determining of whether the output satisfies the functional safety verification comprises generating, by the control system, a secondary output using the calibrated look-up table and determining, by the control system, whether the primary and secondary outputs are sufficiently similar,
wherein the use of the calibrated look-up table for the functional safety verification of the primary output reduces a processing load on the control system by eliminating a need for a secondary execution of the neural network model to obtain the secondary output.
13 . The calibration method of claim 11 , further comprising identifying the plurality of breakpoints by (i) determining, by the computer system, a minimum/maximum step and a slope deviation for identifying a breakpoint.
14 . The calibration method of claim 13 , further comprising identifying the plurality of breakpoints by (ii) determining, by the computer system, an instantaneous slope at a first data point and creating, by the computer system, a line with the determined instantaneous slope through the first data point.
15 . The calibration method of claim 14 , further comprising identifying the plurality of breakpoints by (iii) stepping, by the computer system, to a second data point and comparing, by the computer system, a Y-value of the second data point to a Y-value of the created line.
16 . The calibration method of claim 15 , further comprising identifying the plurality of breakpoints by (iv) identifying, by the computer system, the first data point as a breakpoint when the difference between the Y-values of the second data point and the created line is greater than the slope deviation.
17 . The calibration method of claim 16 , further comprising identifying, by the computer system, the plurality of breakpoints by continuing identifying breakpoints until the maximum number of breakpoints have been identified.
18 . The calibration method of claim 13 , wherein the multi-dimensional surface is a two-dimensional (2D) surface.
19 . The calibration method of claim 13 , wherein the multi-dimensional surface is a three-dimensional (3D) surface, and wherein the method further comprises dividing, by the computer system, the 3D surface into a plurality of 2D surfaces.
20 . The calibration method of claim 19 , further comprising:
Identifying, by the computer system, the plurality of breakpoints for each of the plurality of 2D surfaces; and
determining, by the computer system, a plurality of breakpoints for the 3D surface by calculating a weighted sum of an average and a maximum of the plurality of breakpoints for the plurality of 2D surfaces, respectively.