Autonomous apparatus

Patent metadata

Field	Value
Publication number	US-11695359-B2
Application number	US-201917050346-A
Country	US
Kind code	B2
Filing date	Apr 24, 2019
Priority date	Apr 24, 2018
Publication date	Jul 4, 2023
Grant date	Jul 4, 2023

Abstract

The disclosure relates to an autonomous apparatus, moving and performing preset work in a defined working area, the autonomous apparatus including an energy module supplying energy to the autonomous apparatus, a motor, a sensor circuit, and a control circuit, the motor obtaining the energy from the energy module, to drive the autonomous apparatus to move and/or work in the working area, the sensor circuit detecting working parameters and environmental parameters of the autonomous apparatus, and transmitting detection results to the control circuit, the control circuit controlling the operation of the motor according to a signal transmitted by the sensor circuit, where the motor is a sensorless brushless motor, and before the motor rotates, the control circuit measures a resistance value of the motor, and estimates, one the basis of the resistance value of the motor, a rotor position of the motor, so as to control the operation of the motor.

First claim

What is claimed is:

1. An autonomous apparatus, traversing and performing preset work in a defined working area, the autonomous apparatus comprising:
an energy module configured to supply energy to the autonomous apparatus,
a motor,
a sensor circuit, and
a control circuit,
wherein the motor obtains energy from the energy module to drive the autonomous apparatus to traverse within the defined working area and perform work therein,
wherein the sensor circuit detects a working parameter and an environmental parameter of the autonomous apparatus, and transmits a detection result to the control circuit,
wherein the control circuit controls an operation of the motor according to a signal transmitted by the sensor circuit,
wherein the motor is a sensorless brushless motor, and before the motor rotates, the control circuit measures a resistance value of the motor and estimates a rotor position of the motor based on the resistance value of the motor, to control the operation of the motor,
wherein the control circuit comprises an inverter circuit,
wherein the control circuit applies a first voltage value V1 to any two phases of the motor through the inverter circuit, so that a phase current flowing through the motor reaches a first current value I1,
wherein the control circuit applies a second voltage value V2 to any two phases of the motor through the inverter circuit, so that the phase current flowing through the motor reaches a second current value I2, and
wherein the control circuit measures the resistance value of the motor based on the first voltage value V1, the first current value I1, the second voltage value V2, and the second current value I2.

2. The autonomous apparatus according to claim 1 , wherein in a process of applying a voltage to any two phases of the motor by the control circuit, a duty ratio is gradually increased until the phase current flowing through the motor reaches the first current value I1 or the second current value I2.

3. The autonomous apparatus according to claim 1 , wherein the control circuit is a field oriented control (FOC) circuit.

4. The autonomous apparatus according to claim 3 , wherein when the control circuit determines, based on the rotor position of the motor, that a rotation speed of the motor is less than a first preset rotation speed, the control circuit controls a d-axis current Id to be a non-zero positive value.

5. The autonomous apparatus according to claim 4 , wherein the control circuit controls the d-axis current Id to decrease as the rotation speed of the motor increases.

6. The autonomous apparatus according to claim 5 , wherein the control circuit controls the d-axis current Id to linearly decrease as the rotation speed increases.

7. The autonomous apparatus according to claim 4 , wherein when the rotation speed of the motor is greater than the first preset rotation speed, the control circuit controls the d-axis current Id to be zero.

8. The autonomous apparatus according to claim 1 , wherein the motor comprises a walking motor and a working motor, the walking motor drives the autonomous apparatus to traverse the working area, and the working motor drives the autonomous apparatus to perform the preset work.

9. The autonomous apparatus according to claim 1 , wherein after the motor starts rotating, the control circuit estimates the rotor position of the motor based on the resistance value of the motor measured before the motor rotates, and controls the operation of the motor according to an estimation result.

Assignees

• Positec Power Tools Suzhou Co Ltd

Inventors

• Testolin Federico
• Dalfra Davide

Classifications

• A01D34/78

  electric · CPC title

• H02P21/22

  Current control, e.g. using a current control loop · CPC title

• A01D34/008

  for automated or remotely controlled operation · CPC title

• A01D34/74

  Cutting-height adjustment · CPC title

• A01D34/64

  mounted on a vehicle, e.g. a tractor, or drawn by an animal or a vehicle (A01D34/695 takes precedence) · CPC title