Search

EP-3853622-B1 - SELF VALIDATION OF CONTROLLER INTERNAL CIRCUITS

EP3853622B1EP 3853622 B1EP3853622 B1EP 3853622B1EP-3853622-B1

Inventors

  • SILLIMAN, WILLIAM C.
  • HOFSDAL, GILBERT B.
  • WASER, DANIEL L.
  • SHAPIRO, Aryn

Dates

Publication Date
20260513
Application Date
20190909

Claims (12)

  1. A system for testing circuit operation, the system comprising: a circuit comprising a power source (310; 312), a switching element (306a; 306b), and a load (350; 352); and an analog to digital converter (304) configured to receive electrical values from a first node between the switching element (306a; 306b) and the load (350; 352), the analog to digital converter (304) communicatively coupled to a microcontroller (302), wherein the microcontroller (302) is configured to perform a diagnostic operation for the circuit comprising: obtaining, by the analog to digital converter (304), first data associated with the load (350; 352) responsive to operating the switching element (306a; 306b) to turn ON, wherein the first data comprises electrical values from a second node, wherein the second node is between a first resistor (332; 334) connected to the first node and a second resistor (338) connected to a reference voltage; obtaining, from the analog to digital converter (304), second data associated with an output of the switching element (306a; 306b), wherein the second data comprises electrical values obtained at the output of the switching element (306a; 306b); and analyzing the first data and the second data to determine a fault condition for the circuit, wherein analyzing the first data comprises comparing the electrical values from the second node to an operational range of values for the load (350; 352), wherein analyzing the second data comprises comparing the electrical values obtained at the output of the switching element (306a; 306b) to an operational range of values for the output of the switching element (306a; 306b), and wherein the diagnostic operation for the circuit further comprises associating the fault condition with the load (350; 352) based on: a determination that the electrical values from the second node are outside the operational range of values for the load (350; 352); and a determination that the electrical values obtained at the output of the switching element (306a; 306b) are inside the operational range of values for the output of the switching element (306a; 306b).
  2. The system of claim 1, wherein the system further comprises: a sensing element arranged between the power source (310; 312) and the switching element (306a; 306b), the sensing element communicatively coupled to the analog to digital converter (304), wherein the diagnostic operation for the circuit further comprises: obtaining, from the sensing element, sensor data associated with the power source (310; 312), wherein the sensor data comprises electrical values associated with the power source (310; 312); and comparing the electrical values associated with the power source (310; 312) to an operation range of values for the power source (310; 312).
  3. The system of claim 2, wherein the diagnostic operation for the circuit further comprises: associating the fault condition with the switching element (306a; 306b) based on: a determination that the electrical values obtained at the output of the switching element (306a; 306b) are outside the operational range of values for the output of the switching element (306a; 306b); and a determination that the electrical values associated with the power source (310; 312) are inside the operational range of values for the power source (310; 312).
  4. The system of claim 2, wherein the diagnostic operation for the circuit further comprises: associating the fault condition with the power source (310; 312) based on a determination that the electrical values associated with the power source (310; 312) are outside the operational range of values for the power source (310; 312).
  5. The system of claim 1, wherein the diagnostic operation for the circuit further comprises: generating an alert based on the fault condition; and displaying, on a display device, the alert.
  6. The system of claim 2, wherein the sensing element comprises a voltage sensing circuit.
  7. The system of claim 1, wherein the circuit is a control system (86) for a trailer refrigeration unit (64).
  8. A method for testing circuit operation, the method comprising: obtaining, by a processor (302) from an analog to digital converter (304) in a circuit, first data associated with a load (350; 352) on the circuit, wherein the circuit comprises a power source (310; 312) and a switching element (306a; 306b), and the analog to digital converter (304) is configured to receive electrical signals from a first node between the switching element (306a; 306b) and the load (350; 352); wherein the first data is obtained responsive to operation of the switching element (306a; 306b) to turn ON; wherein the first data comprises electrical values from a second node, wherein the second node is between a first resistor (332; 334) connected to the first node and a second resistor (338) connected to a reference voltage; obtaining, from the analog to digital converter (304), second data associated with an output of the switching element (306a; 306b), wherein the second data comprises electrical values obtained at the output of the switching element (306a; 306b); and analyzing the first data and the second data to determine a fault condition for the circuit, wherein analyzing the first data comprises comparing the electrical values from the second node to an operational range of values for the load (350; 352), wherein analyzing the second data comprises comparing the electrical values obtained at the output of the switching element (306a; 306b) to an operational range of values for the output of the switching element (306a; 306b), and wherein the method further comprises associating the fault condition with the load (350; 352) based on: a determination that the electrical values from the second node are outside the operational range of values for the load (350; 352); and a determination that the electrical values obtained at the output of the switching element (306a; 306b) are inside the operational range of values for the output of the switching element (306a; 306b).
  9. The method of claim 8 further comprising: obtaining, from a sensing element in the circuit, sensor data associated with the power source (310; 312), wherein the sensor data comprises electrical values associated with the power source (310; 312); and comparing the electrical values associated with the power source (310; 312) to an operation range of values for the power source (310; 312).
  10. The method of claim 9 further comprising: associating the fault condition with the switching element (306a; 306b) based on: a determination that the electrical values obtained at the output of the switching element (306a; 306b) are outside the operational range of values for the output of the switching element (306a; 306b); and a determination that the electrical values associated with the power source (310; 312) are inside the operational range of values for the power source (310; 312).
  11. The method of claim 9 further comprising: associating the fault condition with the power source (310; 312) based on a determination that the electrical values associated with the power source (310; 312) are outside the operational range of values for the power source (310; 312).
  12. The method of claim 8 further comprising: generating an alert based on the fault condition; and displaying, on a display device, the alert.

Description

BACKGROUND Exemplary embodiments pertain to the art of circuitry diagnostics and more particularly to self-validation of container controller internal circuits. Transport refrigeration units (TRUs) are containers designed to carry perishable freight at a specific temperature or within a temperature range. TRUs can be equipped with a variety of refrigeration systems for maintaining a specific temperature within the cabin. Typically, a control system operates the refrigeration system to maintain the temperature inside the cabin. These control systems consist of circuit elements that can malfunction over time. In addition, connections between components of the control system can degrade or become disconnected. For example, a load on the control system can lose the mechanical connection with the pins of the control system. Instead of just replacing the control system when there is a malfunction, there exists a need for a testing process for the various locations within the circuitry of the control system to identify the cause of the malfunction. US 2013/009648 discloses a battery management system which controls the switching of switches in a circuit and monitors the circuit voltage and current to determine if any of the switches are faulty. US2014/327450A1 discloses an IC with switches driving a load, wherein the switches are controlled on/off in various sequences to identify a number of load faults such as opens, shorts, over-current. Fault states are identified using comparators. BRIEF DESCRIPTION According to a first aspect there is provided a system for testing circuit operation, the system comprising: a circuit comprising a power source, a switching element, and a load; an analog to digital converter configured to receive electrical values from a first node between the switching element and the load, the analog to digital converter communicatively coupled to a microcontroller, wherein the microcontroller is configured to perform a diagnostic operation for the circuit comprising: obtaining, by the analog to digital converter, first data associated with the load responsive to operating the switching element to turn ON, wherein the first data comprises electrical values from a second node, wherein the second node is between a first resistor connected to the first node and a second resistor connected to a reference voltage; obtaining, from the analog to digital converter, second data associated with an output of the switching element, wherein the second data comprises electrical values obtained at the output of the switching element; and analyzing the first data and the second data to determine a fault condition for the circuit. Analyzing the first data includes comparing the electrical values from the second node to an operational range of values for the load. Analyzing the second data includes comparing the electrical values obtained at the output of the switching element to an operational range of values for the output of the switching element. The diagnostic operation for the circuit further includes associating the fault condition with the load based on a determination that the electrical values from the second node are outside the operational range of values for the load and a determination that the electrical values obtained at the output of the switching element are inside the operational range of values for the output of the switching element. The system may further include a sensing element arranged between the power source and the switching element, the sensing element communicatively coupled to the analog to digital converter, wherein the diagnostic operation for the circuit further includes obtaining, from the sensing element, sensor data associated with the power source, wherein the sensor data comprises electrical values associated with the power source and comparing the electrical values associated with the power source to an operation range of values for the power source. The diagnostic operation for the circuit may further include associating the fault condition with the switching element based on a determination that the electrical values obtained at the output of the switching element are outside the operational range of values for the output of the switching element and a determination that the electrical values associated with the power source are inside the operational range of values for the power source. The diagnostic operation for the circuit may further include associating the fault condition with the power source based on a determination that the electrical values associated with the power source are outside the operational range of values for the power source. The diagnostic operation for the circuit may further include generating an alert based on the fault condition and displaying, on a display device, the alert. The system may include that the sensing element comprises a voltage sensing circuit. The circuit may be a control system for a trailer refrigeration unit. According to