Automatic parking brake actuation and failure detection
Embodiments are disclosed for improving safety with parking brake actuation. In particular, embodiments inhibit or allow parking brake commands based on an operation state of a vehicle. Further, embodiments act on parking brake commands based on a health or condition of the parking brakes themselves. An example method for autonomous operation of a vehicle includes receiving a command to apply a parking brake of the vehicle; determining a vehicle operation state based on comparing a speed of the vehicle to a range of pre-determined values; configuring an instruction for engagement of the parking brake according to the vehicle operation state; determining a brake health of the parking brake; and transmitting the instruction to the parking brake to cause the parking brake to be engaged based on the brake health satisfying one or more thresholds.
1. A vehicle configured for autonomous operation, comprising:
a first set of brakes;
a second set of brakes; and
a braking controller comprising at least one processor and a memory storing instructions that, when executed by the at least one processor, cause the braking controller to implement a method comprising:
receiving, from an autonomous controller of the vehicle, a command to apply the first set of brakes of the vehicle;
determining a vehicle operation state of the vehicle based on comparing a speed of the vehicle that is determined via a plurality of sensor signals from a set of sensors on the vehicle with a range of pre-determined values;
in response to the vehicle operation state being a stationary state, determining a brake health of the first set of brakes; and
based on the brake health failing to satisfy one or more thresholds, transmit an instruction to the second set of brakes to cause the second set of brakes to be engaged instead of the first set of brakes specified by the received command.
2. The vehicle of claim 1 , wherein the method implemented by the braking controller further comprises:
receiving, from the autonomous controller, a second command to apply the first set of brakes;
determining a second vehicle operation state based on comparing a second speed of the vehicle to the range of pre-determined values, the second speed corresponding to a time associated with receiving the second command; and
according to the second vehicle operation state being determined to be a transient state, causing the second command to be inhibited such that the second set of brakes are engaged instead of the first set of brakes.
3. The vehicle of claim 1 , wherein the brake health includes a usage counter that indicates a number of instances that the first set of brakes has been engaged, and wherein the one or more thresholds includes a counter threshold that is satisfied based on the usage counter being less than the counter threshold.
4. The vehicle of claim 1 , wherein the brake health includes a response delay of the first set of brakes, and wherein the one or more thresholds includes a delay threshold that is satisfied based on the response delay being less than the delay threshold.
5. The vehicle of claim 1 , wherein the first set of brakes includes a parking brake, and wherein the second set of brakes includes a primary foundation brake and a redundant foundation brake.
6. The vehicle of claim 1 , wherein the command is received by the braking controller from the autonomous controller via an electronic communication channel between the braking controller and the autonomous controller.
7. The vehicle of claim 1 , wherein the determining of the brake health is performed independent of receiving the command to apply the parking brake.
8. A system for autonomous operation of a vehicle, the system comprising:
(i) a command inhibiting module configured to:
receive, from an upstream module of the system, a command to apply a parking brake of the vehicle,
determine a vehicle operation state based on comparing a speed of the vehicle to a range of pre-determined values, and
based on the vehicle operation state being determined to be a stationary state, forward the command to a health monitoring module of the system; and
(ii) the health monitoring module configured to:
determine a brake health of the parking brake, and
based on the brake health satisfying one or more thresholds, transmit an instruction to the parking brake to cause the parking brake to be engaged.
9. The system of claim 8 , wherein the command inhibiting module is further configured to, based on a particular vehicle operation state, inhibit the command to apply the parking brake.
10. The system of claim 8 , wherein the health monitoring module is further configured to, based on the brake health failing to satisfy the one or more thresholds, transmit an instruction to an alternative brake unit of the vehicle to cause the alternative brake unit to be engaged, and wherein the alternative brake unit includes a primary foundation brake and a redundant foundation brake.
11. The system of claim 8 , wherein the brake health is determined by the health monitoring module based on a usage counter that indicates a number of instances that the parking brake has been engaged.
12. The system of claim 8 , wherein the brake health is determined by the health monitoring module based on a response delay of the parking brake.
13. The system of claim 8 , wherein the health monitoring module is configured to determine the brake health of the parking brake at a first frequency that is greater than or equal to a second frequency at which the command inhibiting module determines the vehicle operation state.
14. The system of claim 8 , wherein the command inhibiting module is configured to obtain a plurality of sensor signals from a set of sensors that describe a rotational speed of each wheel of the vehicle and a rotational speed of a transmission output shaft of the vehicle, wherein the speed of the vehicle is determined from the plurality of sensor signals.
15. A method for autonomous operation of a vehicle, comprising:
receiving, by a braking controller of the vehicle from an autonomous controller of the vehicle, a command to apply a parking brake of the vehicle;
determining, by the braking controller, a vehicle operation state based on comparing a speed of the vehicle to a range of pre-determined values, wherein the speed of the vehicle is obtained from a first set of sensors of the vehicle;
according to the vehicle operation state being determined to be a stationary state, determining, by the braking controller, a brake health of the parking brake; and
based on the brake health satisfying one or more thresholds, transmitting, by the braking controller, an instruction to the parking brake to cause the parking brake to be engaged.
16. The method of claim 15 , further comprising:
receiving, from the autonomous controller of the vehicle, a second command to apply the parking brake of the vehicle; and
inhibiting the second command such that an alternative set of brakes are engaged instead of the parking brake, based on the speed of the autonomous truck being outside of the range of pre-determined values.
17. The method of claim 16 , further comprising:
indicating an inhibition of the second command to an operator of the vehicle via a display located on the vehicle.
18. The method of claim 16 , wherein the alternative set of brakes includes a primary foundation brake and a redundant foundation brake.
19. The method of claim 15 , wherein the braking controller determines the brake health of the parking brake based on a usage counter that indicates a number of instances that the parking brake has been engaged.
20. The method of claim 15 , wherein the braking controller determines the brake health of the parking brake based on a response delay of the parking brake.