Apparatuses and methods for monitoring stall of motors
AssigneeVenture Measurement
InventorsMichael Starinki, Christopher Hampton, Brian Jamieson
Life of this patent
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Abstract
A system and method for monitoring a level of material in a storage bin, including a gear train, a gear train shaft rotatably coupled to the gear train, a drive shaft, a coupling system to couple the gear train shaft to the drive shaft, a paddle coupled to the drive shaft to rotate in unison therewith, the paddle configured to engage a material in the storage bin when the level of material reaches a threshold level, and a stepper motor. A controller may be communicatively coupled to the stepper motor wherein the controller is configured to monitor the running state and the stall state of the stepper motor.
Claims20
An apparatus for monitoring a level of material in a storage bin, the apparatus comprising:
- a gear train;
- a gear train shaft rotatably coupled to the gear train;
- a drive shaft;
- a coupling system to couple the gear train shaft to the drive shaft, the coupling system configured to impart rotation motion between the gear train shaft and the drive shaft;
- a paddle coupled to the drive shaft to rotate in unison therewith, the paddle configured to engage a material in the storage bin when the level of material reaches a threshold level;
- a stepper motor having at least two states of operation, the stepper motor operatively coupled to the gear train to drive the gear train shaft to impart torque on the drive shaft and the paddle during a first state of operation and the material engaging the paddle to cause the stepper motor to switch to a second state of operation;
- and
- a controller communicatively coupled to the stepper motor for monitoring the state of the stepper motor.
A method for monitoring an operational state of a motor in one of a variety of operating conditions, the method comprising:
- measuring a duration of presence of a back electromotive force (BEMF) during operation of a motor;
- comparing the duration with a respective threshold duration of BEMF of the motor in one or more operating states;
- and
- identifying the particular operating state of the motor.
The method of claim 14 wherein the range of stall torque values correspond to a respective density of a material being monitored in a storage bin, the stall torque being proportional to the density of the material.
A method to monitor a fault in an apparatus for monitoring a level of material in a storage bin for one of a variety of operating conditions, the method comprising:
- defining a threshold duration of BEMF for a range of stall torque values of a running motor, each stall torque value being proportional to a peak current of the motor and applicable to the respective operating condition;
- setting the stall torque value of the motor;
- measuring a sample duration of presence of BEMF during operation of the motor;
- and
- comparing the sample duration with the selected threshold duration of BEMF to determine if the apparatus has a fault, the comparison indicative of a fault in the apparatus when the sample duration is lower than the threshold duration of the running motor and the comparison indicative of an operational apparatus when the sample duration is higher than the threshold duration of the running motor, wherein the fault in the apparatus causes additional torque applied to the motor.
A method for detecting the presence of a defect in a gear train comprising:
- setting a motor direction to reverse and determining whether the motor moves in the reverse direction;
- setting a motor direction to forward and determining whether the motor moves in the forward direction;
- determining from the movement of the motor whether the motor is in a stalled condition;
- and
- diagnosing the health of the gear train based on whether the motor is in the stalled condition.
Dependencies are inferred from the claim text.