Alerts

We are monitoring many aspects of Molly, and with this monitoring information we can configure the monitoring system to alert us to any conditions that are a problem, or could become a problem if not addressed. Molly’s alert system is a bit like a check engine light, but as two levels of alerts. Warnings indicate an alert condition that should be investigated, but do not require immediate attention. Alarms on the other hand indicates an alert condition which needs to be investigated immediately. Typically if warnings are not addressed, then they turn into alarms.

As an example, if state of charge of the house batteries falls below a certain level, this is a warning. If the batteries continue to drain, it will ultimate trigger the alarm.

An alarm will immediately sound the buzzer. To ensure the buzzer does not startle the driver while driving, it will “chirp” fives times then activate a continuous alarm. The buzzer can be silenced for 1 hour, after which it will reactivate. A warning will “chirp” the buzzer every 10 minutes until it is corrected or disabled.

Alerts are configured for the following areas. This list is growing each time I find time to write more software to add more alerts.

Tire Pressure. Each tire has a pressure sensor and each sensor is configured with a nominal tire pressure setting. Each sensor can independently raise an alarm where the tire pressure deviates from this nominal setting. The exact logic is a little unclear, as the alarm logic is built into the sensor and is programmed by the sensor manufacture. If any tire sensor sends an alarm, then this triggers Molly’s alarm. In addition to these alarms, we have also configured the following extra warnings and alarms:

  • Cross-axle pressure differential exceeds 10% for more than 1 minute is a warning and exceeding 20% is an instantaneous alarm.
  • Cross-axle temperature differential exceeds 10ºC for more than 1 minute is a warning and 15ºC is an instantaneous alarm.
  • Communication has been lost with the TPMS system for greater than 90 seconds is a warning and greater than 10 minutes is an alarm. Communication is also deemed to be lost even when messages are being received but where these are failing their checksum and therefore maybe invalid.

Battery Condition. The house batteries are monitored by a smart shunt, which is able to keep an eye on our batteries with its on alarm logic. This includes alarms for low state of charge, low or high battery voltages and low or high temperature readings. These alarm will activate when the value reaches a set threshold and will deactivate once when the value clears this threshold. If the smart shunt triggers an alarm, then this immediately triggers Molly’s alarm. In addition to these alarms, we have also configured the following extra warnings and alarms:

  • Warning when the State of Charge is below 20%, which represents about 1 day of useful charge remaining. The smart shunt alarm is set at 10% State of Charge.
  • Warning when the battery voltage exceeds 14.4 volts, which is higher what the power sources should generate. The smart shunt alarm is set at 14.6 volts. The BMS will automatically disconnect if the voltage exceeds 15 volts (+/- 0.12 volts)
  • Warning when the battery voltage drops below 12.5 volts, based on voltage vs percentage charge remaining charts provided by the battery manufacture. The smart shunt alarm is set at 12.0 volts. The BMS will automatically disconnect if the voltage is below 10.2 volts (+/- 0.2 volts).
  • Warning when battery temperature is below 15ºC for more than 4 hours, which is lower limit of the optimal battery temperature. The smart shunt alarm is set at -15ºC. The battery BMS low temperature protection operates at -20ºC.
  • Warning when battery temperature exceeds 35ºC which is the upper limit of optimal battery temperature. The smart shunt alarm is set at 55ºC, which is the maximum operating temperature. The battery BMS high temperature protection operates at 65ºC.
  • Communication has been lost with the smart shunt for greater than 30 seconds is a warning and greater than 10 minutes is an alarm. Communication is also deemed to be lost even when messages are being received but where these are failing their checksum and therefore maybe invalid.

ECU. The truck has it’s own alarm system and will turn on the check engine light (or malfunction indicator lamp). Check engine light is considered a warning. The FUSO truck can indicate other faults on the dashboard, and not all of these fault conditions are visible to Molly’s monitoring system. So the FUSO dashboard is the primary location alerts are presented. However, the following warnings have also been configured.

  • Trip Odometer has changed by more than 5 miles between readings, which is inplausable.
  • Communication has been lost with the ECU for greater than 90 seconds.. Communication is also deemed to be lost even when messages are being received but where these are failing their checksum and therefore maybe invalid.