Patent Application
20230364968
This disclosure relates to automotive cooling systems.
An automotive climate control system may include subsystems and components, such as active heating and cooling elements, that cooperate to maintain cabin and other temperatures. This system is able to manage vehicle internal temperatures through a cycle of processes the either heat or cool air being circulated.
An automotive climate system includes at least one fan and control circuitry. The control circuitry includes at least one speed sensor that detects a speed of the at least one fan, at least one temperature sensor that detects a temperature, and logic gates that, responsive to signals indicative of the speed being less than a threshold speed and the temperature being greater than a threshold temperature, generate output to drive the at least one fan at a speed greater than the threshold speed.
Automotive control circuitry includes a plurality of temperature sensors that generate signals indicative of temperatures, a plurality of first comparators that generate logical output signals based on whether the signals indicative of the temperatures exceed a first threshold value, and an OR gate that generates a logical output signal based on a high or low state of the logical output signals generated by the first comparators. The automotive control circuitry also includes a plurality of speed sensors that generate signals indicative of speeds of fans, a plurality of second comparators that generate logical output signals based on whether the signals indicative of the speeds exceed a second threshold value, and an AND gate that generates a logical output signal based on a high or low state of the logical output signals generated by the second comparators and a high or low state of the logical output signal generated by the OR gate such that the logical output signal generated by the AND gate selectively drives the fans.
An automotive vehicle includes a housing, a plurality of fans arranged relative to the housing, a processor contained by the housing and that generates control signals for the fans, and control circuitry including sensors that detect parameters associated with the housing and fans, and logic gates that, based on signals from the sensors, selectively generate output that interrupts the control signals and drives the fans.
Embodiments are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale. Some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art.
Various features illustrated and described with reference to any one of the figures may be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
Increasingly powerful processors are being packaged into more dense mechanical enclosures within vehicles. The heat generated by these processors as packaged may now require active cooling systems with fans to control the thermal environment. Managing the thermal environment may affect system reliability and stability.
If the cooling systems are unavailable, processors and other components may operate at high temperatures. Without active thermal management, the heat may build up inside any associated mechanical enclosure. Processors and components operating outside normal temperature ranges may cause radio frequency interference, resets of processors, errors in storage systems, and other issues affecting system integrity. Additionally, processors and storage exposed to high temperatures may experience shortened lifetimes.
Some vehicle consumers may expect a quiet vehicle cabin. Cooling fans operating at a high rate of speed may generate noise and because of this, speeds of the fans are controlled. The fans operate at the minimum speed required to manage the thermal environment and reduce the generated noise. Issues associated with the software, control circuit, or connection to the fans may prevent the fans from operating as desired.
Because of the effect high temperatures may have on system integrity, certain systems may include redundant cooling fans. Redundant fans allow the system to manage the thermal environment even with one of the fans being unavailable. This management is provided through a software function. Issues with associated processors or software could prevent proper thermal management of the system.
Vehicle features that operate while the vehicle is off and the driver is not in the vehicle, e.g., camera monitoring of the exterior of the vehicle, are increasing. Reducing the energy consumption of these features can prevent drain on the auxiliary battery (e.g., 12V battery) or reduction of the vehicle range to the extent battery power is used for propulsion. Therefore, processors and/or processor capabilities may not be active while a feature is on but the vehicle is off. This could include the thermal management system. If the system is operated longer than expected in this state, components could be exposed to high temperatures, which may affect system stability and create other issues.
Here, cooling fan control circuitry is contemplated. The circuit, in some examples, monitors multiple temperature sensors and the speed of the redundant cooling fans in parallel with the software function that controls fan speed. The circuit may turn the fan or fans on at full speed if any monitored temperature is above a defined threshold and the speed of all fans is below a defined threshold without any command from software. The circuit may be powered whenever the system has power and does not use the dedicated processor power supply, allowing it to be active independent of the associated processor. Powering the circuit from an independent power supply provides the ability to manage high temperatures even when one or more processors are not active or fully functional.
The temperature monitoring portion of the circuit may use analog temperature sensors whose voltage increases with increasing temperature. The output of these temperature sensors is compared to a calibrated reference voltage using a standard comparator. If the temperature output of any sensors is above the reference voltage, indicating a high temperature, the output of the comparator goes high. The outputs of all the temperature sensor comparators may be OR'd using transistor logic.
The fan speed of all cooling fans may be converted to a voltage using a frequency to voltage circuit whose output increases with increasing frequency. The output of this frequency to voltage converter is compared to a calibrated reference voltage using a standard comparator. If the frequency is too low and therefore the voltage is below the reference voltage, indicating the fan is not spinning, the output of the comparator goes high. The output of all the fan speeds may be AND'd using transistor logic.
The fan speed and temperature sensor monitoring outputs of the circuit may be AND'd together using standard transistor logic. If the fan speeds are too low and the enclosure temperature is above a limit, the circuit may interrupt the processor control signal using a standard buffer and pull the fan control signal high, commanding the fans to full speed.
The outputs of the fan speed and temperature comparators can be connected to a processor in the enclosure. This provides feedback to the software that an issue exists in the cooling system and/or issues in the hardware or software exist.
An advantage of the control circuit may be that it can be implemented with common, readily available and reasonably expensed components. That is, the circuit may be implemented with ordinary operational amplifiers, comparators, transistors, capacitors, and resistors. The control circuit may permit the fan to be turned on even if the processor controlling the fan is not powered. If any processor is active within the controller and fan control is not active, it is possible to heat the system. The control circuit may enable the fan in this situation based on temperature without processor control. The processor commanded fan speed can be over-ridden in the event of a software or processor issue. The circuit may independently monitor the temperature of the enclosure and if it exceeds a limit, the circuit may command the fan to maximum speed independent of the processor commanded fan speed. The control circuit can be expanded to support multiple cooling fans using readily available components.
Referring to
The control circuitry 18 also includes speed sensors 36, 38, 40, comparators 42, 44, 46, and AND gate 48. The speed sensors 36, 38, 40 each detect a frequency corresponding to operation of the fans 12, 14, 16. That is, the speed sensor 36 detects a frequency corresponding to operation of the fan 12, the speed sensor 38 detects a frequency corresponding to operation of the fan 14, and the speed sensor 40 detects a frequency corresponding to operation of the fan 16. In this example, the sensed frequency is converted to a voltage signal such that as the frequency increases, the voltage increases. These signals are provided to the comparators 42, 44, 46. That is, output from the speed sensor 36 is provided to the comparator 42, output from the speed sensor 38 is provided to the comparator 44, and output from the speed sensor 40 is provided to the comparator 46. Each of the comparators 42, 44, 46 is also provided a reference voltage value. This value may be predefined (identified via simulation or testing) and correspond to a threshold speed. The comparators 42, 44, 46 are each configured such that responsive to a value of the voltage signal from the corresponding speed sensor exceeding the reference voltage value, the comparator may output a low signal (e.g., 0). And responsive to the value of the voltage signal from the corresponding speed sensor being less than the reference voltage value, the comparator may output a high signal (e.g., 1). The output from each of the comparators 42, 44, 46 is provided to the processor 20 and the AND gate 48. The processor 20 receives such data to inform it about the speeds associated with the fans 12, 14, 16. It may then, for example, generate user alerts, etc. The output from the OR gate 34 is also provided to the AND gate 34. If any of the comparators 42, 44, 46 outputs a high signal (e.g., 1) and the OR gate 34 outputs a high signal (e.g., 1), the AND gate 48 will output a high signal (e.g., 1). Otherwise, the AND gate 48 will output a low signal (e.g., 0).
The control circuitry also includes drivers 50, 52, 54, buffers 56, 58, 60, and latch 62. The drivers 50, 52, 54 are configured to provide voltage signals to the fans 12, 14, 16 that cause the fans 12,14, 16 to operate at high speed (e.g., higher than the threshold speed) responsive to output of a high signal (e.g., 1) from the AND gate 48. That is, the driver 50 is configured to provide a voltage signal to the fan 12, the driver 52 is configured to provide a voltage signal to the fan 14, and the driver 54 is configured to provide a voltage signal to the fan 16. Otherwise, the drivers 50, 52, 54 do not provide voltage signals to the fans 12, 14, 16. The buffers 56, 58, 60 are configured to interrupt the normal control signals from the processor 20 that control the fans 12, 14, 16 responsive to output of a high signal (e.g., 1) from the AND gate 48. This interrupt functionality permits the voltage signals from the drivers 50, 52, 54 to supplant those from the processor 20. If the processor 20 is not operating properly, the fans 12, 14, 16 can nonetheless receive commands to operate as described above.
The latch 62 is configured to hold a high signal (e.g., 1) from the AND gate 48 until, for example, the climate system 10 is powered down (e.g., key off). Without the latch 62, the AND gate 48 would output a low signal (e.g., 0) as soon as the speeds of the fans 12, 14, 16 exceed the threshold speed: The comparators 42, 44, 46 would output a low signal (e.g., 0) responsive to the fan speeds measured by the speed sensors 36, 38, 40 exceeding the threshold, resulting in the AND gate 48 outputting a low signal (e.g., 0).
Referring to
Referring to
The algorithms, methods, or processes disclosed herein can be deliverable to or implemented by a computer, controller, or processing device, which can include any dedicated electronic control unit or programmable electronic control unit. Similarly, the algorithms, methods, or processes can be stored as data and instructions executable by a computer or controller in many forms including, but not limited to, information permanently stored on non-writable storage media such as read only memory devices and information alterably stored on writeable storage media such as compact discs, random access memory devices, or other magnetic and optical media. The algorithms, methods, or processes can also be implemented in software executable objects. Alternatively, the algorithms, methods, or processes can be embodied in whole or in part using suitable hardware components, such as application specific integrated circuits, field-programmable gate arrays, state machines, or other hardware components or devices, or a combination of firmware, hardware, and software components.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. In the example of
The words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. The words controller and controllers as well as processor and processors may be interchanged herein.
As previously described, the features of various embodiments may be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics may be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes may include, but are not limited to strength, durability, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and may be desirable for particular applications.
