Guiding robots transporting containers using applied force detection
Systems and methods are disclosed for guiding robots transporting containers using applied force detection. In one embodiment, an example mobile robot is configured to transport a container. The mobile robot can include a first sensor, a second sensor, a motor, and a controller. The controller may be configured to determine that the container is loaded, determine, using at least one of the first sensor or the second sensor, a first change in load distribution, and determine a first direction of movement associated with the first change. The controller may cause the motor to automatically propel the mobile robot in the first direction of movement.
1 . An autonomous robot configured to transport a container, the autonomous robot comprising:
a first load cell;
a second load cell arranged along a first axis with respect to the first load cell;
a third load cell arranged along a second axis with respect to the first load cell;
a motor;
a plurality of wheels; and
a controller configured to:
determine that the container is loaded on the autonomous robot;
determine, using at least one of the first load cell and the second load cell, that a first change in load distribution along the first axis satisfies a threshold, wherein the first change is based at least in part on a force applied to the container;
determine a first direction of movement associated with the first change;
cause the motor to propel the autonomous robot in the first direction of movement;
determine that the first change in load distribution is not present based at least in part on removing the force applied to the container;
determine a first rate of change at which the force is removed; and
cause the mobile robot to stop movement at a rate of braking that corresponds to the first rate of change.
2 . The autonomous robot of claim 1 , wherein the controller is further configured to:
determine a second change in load distribution while the motor is propelling the autonomous robot in the first direction of movement;
determine a second direction of movement associated with the second change; and
cause the motor to propel the autonomous robot in the second direction of movement.
3 . The autonomous robot of claim 1 , wherein the controller is further configured to:
determine a second rate of change at which the first change in load distribution occurred;
determine a speed that corresponds to the second rate of change; and
cause the motor to propel the autonomous robot in the first direction of movement at the speed.
4 . The autonomous robot of claim 1 , further comprising:
a lift plate;
wherein the first load cell, the second load cell, and the third load cell are disposed on the lift plate.
5 . A mobile robot configured to transport a container, the mobile robot comprising:
a first sensor;
a second sensor;
a motor; and
a controller configured to:
determine that the container is loaded;
determine, using at least one of the first sensor or the second sensor, a first change in load distribution, wherein the first change is based at least in part on a force applied to the container;
determine a first direction of movement associated with the first change;
cause the motor to propel the mobile robot in the first direction of movement;
determine that the first change in load distribution is not present based at least in part on removing the force applied to the container;
determine a first rate of change at which the force is removed; and
cause the mobile robot to stop movement at a rate of braking that corresponds to the first rate of change.
6 . The mobile robot of claim 5 , wherein the controller is further configured to:
determine a second change in load distribution while the motor is propelling the mobile robot in the first direction of movement;
determine a second direction of movement associated with the second change; and
cause the motor to propel the mobile robot in the second direction of movement.
7 . The mobile robot of claim 5 , wherein the controller is further configured to:
determine, after determining that the container is loaded, a first baseline load distribution using the first sensor and the second sensor;
wherein the first change in load distribution is relative to the first baseline load distribution.
8 . The mobile robot of claim 5 , further comprising:
a brake system;
wherein the controller is configured to cause the mobile robot to stop movement by causing the brake system to be applied.
9 . The mobile robot of claim 5 , wherein the controller is further configured to:
determine a weight of the container using at least one of the first sensor or the second sensor; and
determine that the first change in load distribution along the first axis satisfies a threshold prior to causing the motor to propel the mobile robot, wherein the threshold is a function of the weight.
10 . The mobile robot of claim 5 , wherein the controller is further configured to:
determine that the first change in load distribution has persisted for a first length of time prior to causing the motor to propel the mobile robot.
11 . The mobile robot of claim 5 , further comprising:
a third sensor;
wherein the first sensor and the third sensor are configured to detect a second change in load distribution along a different axis than the first sensor and the second sensor.
12 . The mobile robot of claim 11 , further comprising:
a wheel; and
an actuator;
wherein the controller is further configured to:
cause the actuator to orient the wheel in the first direction of movement.
13 . The mobile robot of claim 11 , further comprising:
a lift plate;
wherein the first sensor, the second sensor, and the third sensor are disposed on the lift plate.
14 . The mobile robot of claim 11 , wherein the first sensor and the second sensor are aligned along a first axis, and the first sensor and the third sensor are aligned along a second axis; and
wherein the first axis and the second axis are non-perpendicular.
15 . The mobile robot of claim 5 , wherein the first sensor comprises a first subsensor and a second subsensor, and the second sensor comprises a third subsensor and a fourth subsensor.
16 . A method comprising:
determining, by a mobile robot comprising a first sensor, a second sensor, and a motor, that a container is loaded on the mobile robot;
determining, using at least one of the first sensor or the second sensor, a first change in load distribution, wherein the first change is based at least in part on a force applied to the container;
determining a first direction of movement associated with the first change;
causing the motor to propel the mobile robot in the first direction of movement;
determining that the first change in load distribution is not present based at least in part on removing the force applied to the container;
determining a first rate of change at which the force is removed; and
causing the mobile robot to stop movement at a rate of braking that corresponds to the first rate of change.
17 . The method of claim 16 , further comprising:
determining a second change in load distribution while the motor is propelling the mobile robot in the first direction of movement;
determining a second direction of movement associated with the second change; and
causing the motor to propel the mobile robot in the second direction of movement.
18 . The method of claim 16 , further comprising:
determining, after determining that the container is loaded, a first baseline load distribution using the first sensor and the second sensor;
wherein the first change in load distribution is relative to the first baseline load distribution.
19 . The method of claim 16 , further comprising:
determining a second rate of change at which the first change in load distribution occurred;
determining a speed that corresponds to the second rate of change; and
causing the motor to propel the mobile robot in the first direction of movement at the speed.