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Known issues

Prerequisites

Here's a list of known issues and proposed ways how to tackle them.

Normally, we're trying our best to fix any issues as soon as possible, but not all of them can be fixed just like that.

Wheels

Tires come off

The tires are made of soft rubber and tend to grip too much on soft surfaces like grass, carpets, etc. Given the Rover relies on skid steering, the tires may come off the wheel rims when turning.

Fix 1: Glue the tires to rims using a cyanoacrylate (minute) glue.

Fix 2: Add more layers of sponge in the tires to make them more stiff. This lowers the contact area between the wheels and the ground, which, in turn, lowers the wheel traction. It may fix the problem on some terrains.

Wheels lift during zero-radius turning

Sometimes one of the front wheels would lift up when the Rover turns in place on soft surfaces like grass, carpets, etc. As the opposite wheel is blocked, there's a momentum of force acting on the Rover suspension beam and lifting the wheel.

Fix 1: Lessen the grip. For ex. let the Rover drive on a dusty surface first or cover the tires in powertape.

Fix 2 (sort of): After finishing each turn, push the 0,0 command to the rover (release the joystick). This will let the rover level the wheels thanks to the force of gravity.

Wheels squeak when driving

When the wheel rim is not 100% coaxial with the wheel bearings, the torque plate teeth act as an elastic joint to make it a bit easier for the motors. Then, the teeth rub in the rim sockets and tend to squeak.

Fix: Lube the teeth with grease, oil, anything.

Excesive friction in one of the wheels

One of the wheels acts odd compared to the others - is slower, more noisy or stuck.

Fix: Check the wheel cap, most probably the encoder cables touch the encoder magnet and block the motor shaft.

Network

Unstable connection in crowded areas

As the Rover access point relies on 2.4 GHz wifi, the connection can become unstable in areas full of people and devices, for ex. trade shows, due to crowded wifi bands.

Fix: Use 5GHz modem built-in the RaspberryPi. For ex. connect the Rover to external 5GHz network and connect to the UI via router.

https://www.leorover.tech/guides/connect-to-network

Software

The joystick in the UI doesn't respond

Fix: Don't use Apple devices.

Rover rotating in odometry without physically moving

When completing the odometry part of tutorial about autonomous navigation, the rover seems to rotate in odometry reading, without actually moving. Reason for that behavior is IMU readings offset - it may provide data indicating the rover moving in the Z axis without the real movement.

Fix: Calibrate IMU to eliminate the offset from the readings.

IMU calibration
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