Controlling operation of a vehicle with a supervisory control module having a fault-tolerant controller
11148678 · 2021-10-19
Assignee
Inventors
- Wen-Chiao Lin (Rochester Hills, MI, US)
- Xinyu Du (Oakland Township, MI)
- Xiaoyu Huang (Troy, MI, US)
- Paul E. Krajewski (Troy, MI, US)
Cpc classification
B60W2050/0297
PERFORMING OPERATIONS; TRANSPORTING
B60W2050/0031
PERFORMING OPERATIONS; TRANSPORTING
B60W10/04
PERFORMING OPERATIONS; TRANSPORTING
B60W10/18
PERFORMING OPERATIONS; TRANSPORTING
B60W2050/0215
PERFORMING OPERATIONS; TRANSPORTING
B60W50/029
PERFORMING OPERATIONS; TRANSPORTING
B60W10/20
PERFORMING OPERATIONS; TRANSPORTING
International classification
B60W50/029
PERFORMING OPERATIONS; TRANSPORTING
B60W10/18
PERFORMING OPERATIONS; TRANSPORTING
B60W50/02
PERFORMING OPERATIONS; TRANSPORTING
B60W50/00
PERFORMING OPERATIONS; TRANSPORTING
Abstract
System and method for controlling operation of a vehicle in real-time with a supervisory control module. A fault detection module is configured to receive respective sensor data from one or more sensors in communication with the vehicle and generate fault data. The supervisory control module includes at least one fault-tolerant controller configured to respond to a plurality of faults. The supervisory control module is configured to receive the fault data. When at least one fault is detected from the plurality of faults, the supervisory control module is configured to employ the fault-tolerant controller to generate at least one selected command. The selected command is transmitted to one or more device controllers for delivery to at least one of the respective components of the vehicle. Operation of the vehicle is controlled based in part on the selected command.
Claims
1. A system for controlling operation of a vehicle in real-time, the system comprising: at least one device controller operatively connected to the vehicle and configured to deliver a respective command signal to respective components of the vehicle; a plurality of sensors operatively connected to the vehicle and configured to generate respective sensor data; a fault detection module configured to generate fault data from the respective sensor data; a supervisory control module in communication with the at least one device controller and having at least one fault-tolerant controller configured to respond to a plurality of faults; wherein the supervisory control module includes a processor and tangible, non-transitory memory on which instructions are recorded, execution of the instructions by the processor causing the supervisory control module to: receive the fault data and determine if at least one fault is detected from the plurality of faults; when the at least one fault is detected, employ the at least one fault-tolerant controller to generate at least one selected command based in part on the at least one fault; transmit the at least one selected command to the at least one device controller for delivery to at least one of the respective components; and control operation of the vehicle based in part on the at least one selected command; and wherein the at least one fault-tolerant controller includes a reinforcement-learning controller at least partially characterized by an action-value function Q(a,s), where a is an available action for the vehicle, s is an observed state of the vehicle and the action-value function Q(a,s) indicates an estimated value of the available action a based in part on a potential sequence of events occurring after the available action a is taken.
2. The system of claim 1, wherein: the plurality of sensors includes an inertial sensor, an imaging unit, a navigation sensor, a tire pressure sensor and a wheel speed sensor.
3. The system of claim 1, wherein: the respective components include at least one tire, at least one wheel, a brake unit, an accelerator unit and a steering unit; and the plurality of faults includes a respective loss of function of the at least one tire, the at least one wheel, the brake unit, the accelerator unit and the steering unit.
4. The system of claim 3, wherein the at least one selected command includes at least two of: a steering control command defining a steering angle and a steering rate configured to keep the vehicle in a predefined trajectory; an accelerate command configured to increase a speed of the vehicle; and a brake command configured to slow the vehicle.
5. The system of claim 1, wherein: the supervisory control module is programmed to prompt a user of the vehicle to take over control of the operation of the vehicle within a predefined time period after the at least one fault is detected.
6. The system of claim 1, wherein: the vehicle includes a takeover function pre-programmed to accept or decline a takeover of the operation of the vehicle by a user; and the supervisory control module is programmed to enable transition to the takeover by the user when the at least one fault is detected and the takeover function is pre-programmed to accept the takeover.
7. The system of claim 1, wherein the at least one fault-tolerant controller includes: a model-based controller characterized by a first dynamic equation (I{umlaut over (ψ)}=N+B), and a second dynamic equation (aψ+{dot over (ψ)}=0); wherein Nis a torque acting on the vehicle due an interaction with a road surface, B is a differential braking control input, ψ is a yaw of the vehicle, {dot over (ψ)} is a yaw rate, {umlaut over (ψ)} is a rate of change of the yaw rate, I is a moment of inertia of the vehicle and a is a positive parameter; and the at least one selected command includes a first brake pressure command (BP.sub.1) and a second brake pressure command (BP.sub.2), the differential braking control input being a difference between the first brake pressure command (BP.sub.1) and the second brake pressure command (BP.sub.2).
8. The system of claim 1, wherein: the at least one fault-tolerant controller includes a model-based controller, a heuristics-based controller, a reinforcement-learning controller and a machine-learning controller; the at least one fault-tolerant controller is configured to respond to the plurality of faults by a respective process; and the at least one selected command is a weighted average of a respective output of the model-based controller, the heuristics-based controller, the reinforcement-learning controller and the machine-learning controller.
9. The system of claim 1, wherein the at least one fault-tolerant controller includes: a heuristics-based controller at least partially characterized by a membership function configured to map each point in an input space to a respective membership value between 0 and 1, the input space being at least one of a steering angle, a steering rate and a speed of the vehicle.
10. The system of claim 1, wherein: the at least one fault-tolerant controller includes a machine-learning controller at least partially characterized by a numerical model; and the numerical model is generated by collecting user behavior data and vehicle dynamics data with an expert user driving the vehicle with the at least fault, the vehicle dynamics data being an input of the numerical model and the user behavior data being an output of the numerical model.
11. A method for controlling operation of a vehicle in real-time, the vehicle having at least one device controller, a plurality of sensors and a supervisory control module with a processor and tangible, non-transitory memory, the method comprising: generating respective sensor data via the plurality of sensors; configuring a fault detection module to generate fault data from the respective sensor data; configuring the supervisory control module with at least one fault-tolerant controller configured to respond to a plurality of faults; including a reinforcement-learning controller in the at least one fault-tolerant controller, the reinforcement-learning controller being at least partially characterized by an action-value function Q(a,s), wherein a is an available action for the vehicle, s is an observed state of the vehicle and the action-value function Q(a,s) indicates an estimated value of the available action a based in part on a potential sequence of events occurring after the available action a is taken; receiving the fault data and determining if at least one fault is detected from the plurality of faults, via the supervisory control module; when the at least one fault is detected, employing the at least one fault-tolerant controller to generate at least one selected command based in part on the at least one fault; transmitting the at least one selected command to the at least one device controller for delivery to at least one respective component of the vehicle; and controlling operation of the vehicle based in part on the at least one selected command.
12. The method of claim 11, wherein: the plurality of sensors include an inertial measurement unit, an imaging unit, a global positioning unit, a tire pressure sensor and a wheel speed sensor; the respective component includes at least one tire, at least one wheel, a brake unit, an accelerator unit and a steering unit; and the plurality of faults includes a respective loss of function of the at least one tire, the at least one wheel, the brake unit, the accelerator unit and the steering unit.
13. The method of claim 12, wherein the at least one selected command includes at least one of: a steering control command defining a steering angle and a steering rate configured to keep the vehicle in a predefined trajectory; an accelerate command configured to increase a speed of the vehicle; and a brake command configured to slow the vehicle.
14. The method of claim 11, further comprising: pre-programming a takeover function in the vehicle to accept or decline a takeover of the operation of the vehicle by a user; and programming the supervisory control module is programmed to enable transition to the takeover by the user when the at least one fault is detected and the takeover function is pre-programmed to accept the takeover.
15. The method of claim 11, further comprising: including a model-based controller in the at least one fault-tolerant controller, the model-based controller being at least partially characterized by a first dynamic equation (I{umlaut over (ψ)}=N+B), and a second dynamic equation (aψ+{dot over (ψ)}=0); wherein Nis a torque acting on the vehicle due an interaction with a road surface, B is a differential braking control input, ψ is a yaw of the vehicle, {dot over (ψ)} is a yaw rate, {umlaut over (ψ)} is a rate of change of the yaw rate, I is a moment of inertia of the vehicle and a is a positive parameter; and including a first brake pressure command (BP.sub.1) and a second brake pressure command (BP.sub.2) in the at least one selected command, the differential braking control input being a difference between the first brake pressure command (BP.sub.1) and the second brake pressure command (BP.sub.2).
16. The method of claim 11, further comprising: including a model-based controller, a heuristics-based controller, a reinforcement-learning controller and a machine-learning controller in the at least one fault-tolerant controller; training the at least one fault-tolerant controller to respond to the plurality of faults by a respective process; and obtaining the at least one selected command as a weighted average of a respective output of the model-based controller, the heuristics-based controller, the reinforcement-learning controller and the machine-learning controller.
17. The method of claim 11, further comprising: including a machine-learning controller in the at least one fault-tolerant controller, the machine-learning controller being at least partially characterized by a numerical model; and generating the numerical model by collecting user behavior data and vehicle dynamics data with an expert user driving the vehicle with the at least fault, the vehicle dynamics data being an input of the numerical model and the user behavior data being an output of the numerical model.
18. A system for controlling operation of a vehicle in real-time, the system comprising: at least one device controller operatively connected to the vehicle and configured to deliver a respective command signal to respective components of the vehicle; a plurality of sensors operatively connected to the vehicle and configured to generate respective sensor data; a fault detection module configured to generate fault data from the respective sensor data; a supervisory control module in communication with the at least one device controller and having at least one fault-tolerant controller configured to respond to a plurality of faults; wherein the supervisory control module includes a processor and tangible, non-transitory memory on which instructions are recorded, execution of the instructions by the processor causing the supervisory control module to: receive the fault data and determine if at least one fault is detected from the plurality of faults; when the at least one fault is detected, employ the at least one fault-tolerant controller to generate at least one selected command based on the at least one fault; transmit the at least one selected command to the at least one device controller for delivery to at least one of the respective components; and control operation of the vehicle based in part on the at least one selected command; wherein the at least one fault-tolerant controller includes a model-based controller, a heuristics-based controller, a reinforcement-learning controller and a machine-learning controller, the at least one fault-tolerant controller being configured to respond to the plurality of faults by a respective process; and wherein the at least one selected command is a weighted average of a respective output of the model-based controller, the heuristics-based controller, the reinforcement-learning controller and the machine-learning controller.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION
(6) Referring to the drawings, wherein like reference numbers refer to like components,
(7) Referring to
(8) Referring to
(9) Referring to
(10) Referring to
(11) Referring to
(12) Referring to
(13) Referring to
(14) Referring now to
(15) Referring to
(16) Referring now to
(17) Per block 206 of
(18) Per block 210 of
(19) If the takeover function T was pre-programmed to decline the takeover or the user U declined after being prompted, the method 200 proceeds to block 214, where the supervisory control module 100 is programmed to determine if the at least one fault is covered by the control strategies from the fault-tolerant controller F. In other words, it is determined whether the at least one fault is present in the list of the plurality of faults that the fault-tolerant controller F has been configured to respond to. If the fault has been covered, the method 200 moves to block 218. If not, the method 200 proceeds to block 216 where alternative modes of operation (such as limp-home mode or other mode restricting energy consumption and/or speed of the vehicle 12) are executed. The method 200 may be looped back to block 214 or block 212 (see line 215).
(20) Per block 218 of
(21) Per block 224 of
(22) Per block 226 of
(23) Per block 228 of
(24) The heuristics-based controller F.sub.2 (e.g. based on fuzzy logic) may be characterized by a membership function configured to map each point in an input space to a respective membership value between 0 and 1. The input space is at least one of a steering angle, a steering rate and a speed of the vehicle 12. In one example, the membership function is a Gaussian function. In another example, the membership function is a Poisson function. As understood by those skilled in the art, fuzzy machine learning or optimization procedures may be employed to determine the membership function and the rules selected. An example rule may be:
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Here x.sub.i may be a yaw, yaw rate an error in yaw, a tire pressure or other signal, y.sub.i is the selected command (such as a steering angle, a braking force or acceleration force), A.sub.i and B.sub.i are fuzzy sets and μ.sub.i is the membership function of rule i.
(26) The reinforcement-learning controller F.sub.3 may be characterized by an action-value function Q(a,s), where a is an available action for the vehicle, s is an observed state of the vehicle and the action-value function Q(a,s) indicates an estimated value of the available action a considering or based in part on a potential sequence of events (which may include subsequent actions and device reactions) occurring after the available action a is taken. The action-value function Q (a,s) having the value for each observed state is utilized to generate the selected command.
(27) The machine-learning controller F.sub.4 may be characterized by a numerical model obtained by collecting user behavior data and vehicle dynamics data with an expert user driving the vehicle 12 with the at least fault. The numerical model may be derived from the vehicle dynamics data and the user behavior data, as the vehicle dynamics data is the input to the numerical model and the user behavior data is the output of the numerical model. The user behavior may include a pattern of steering, accelerating and braking. The vehicle dynamics may include a steering angle, vehicle speed, linear acceleration and rotational acceleration in multiple directions. The machine-learning controller F.sub.4 may be characterized by a support vector machine (SVM) regression defining a control function as f(x)=w.Math.ϕ(x)+b. Here f(x) is a cost function for each observed state of the vehicle, ϕ(x) is a selected action, and w, b are parameters obtained by solving the following optimization problem to construct the maximum-margin hyper-plane in :
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Here C is a given cost parameter to control the penalty of classification error, ξ is a slack variable which is the distance between x.sub.i and the hyperplane, y.sub.i is the action of an experienced driver when x.sub.i is observed and l is the number of featured data points.
(29) Referring now to
(30) Referring to
(31) The control center C and/or supervisory control module 100 include a computer-readable medium (also referred to as a processor-readable medium), including a non-transitory (e.g., tangible) medium that participates in providing data (e.g., instructions) that may be read by a computer (e.g., by a processor of a computer). Such a medium may take many forms, including, but not limited to, non-volatile media and volatile media. Non-volatile media may include, for example, optical or magnetic disks and other persistent memory. Volatile media may include, for example, dynamic random-access memory (DRAM), which may constitute a main memory. Such instructions may be transmitted by one or more transmission media, including coaxial cables, copper wire and fiber optics, including the wires that comprise a system bus coupled to a processor of a computer. Some forms of computer-readable media include, for example, a floppy disk, a flexible disk, hard disk, magnetic tape, other magnetic media, a CD-ROM, DVD, other optical media, punch cards, paper tape, other physical media with patterns of holes, a RAM, a PROM, an EPROM, a FLASH-EEPROM, other memory chips or cartridges, or other media from which a computer can read.
(32) Look-up tables, databases, data repositories or other data stores described herein may include various kinds of mechanisms for storing, accessing, and retrieving various kinds of data, including a hierarchical database, a set of files in a file system, an application database in a proprietary format, a relational database management system (RDBMS), etc. Each such data stores may be included within a computing vehicle employing a computer operating system such as one of those mentioned above, and may be accessed via a network in one or more of a variety of manners. A file system may be accessible from a computer operating system, and may include files stored in various formats. An RDBMS may employ the Structured Query Language (SQL) in addition to a language for creating, storing, editing, and executing stored procedures, such as the PL/SQL language mentioned above.
(33) The detailed description and the drawings or FIGS. are supportive and descriptive of the disclosure, but the scope of the disclosure is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed disclosure have been described in detail, various alternative designs and embodiments exist for practicing the disclosure defined in the appended claims. Furthermore, the embodiments shown in the drawings or the characteristics of various embodiments mentioned in the present description are not necessarily to be understood as embodiments independent of each other. Rather, it is possible that each of the characteristics described in one of the examples of an embodiment can be combined with one or a plurality of other desired characteristics from other embodiments, resulting in other embodiments not described in words or by reference to the drawings. Accordingly, such other embodiments fall within the framework of the scope of the appended claims.