Robot control problems
From Combat Robot
Given forward command, robot backs up.
If your transmitter has servo reversing (most do - read the manual) reverse the setting for the two channels that feed your ESCs. If no servo reversing is available, switch the power lead polarity at both motors.
Given forward command, robot spins in place.
If your transmitter has servo reversing (most do) reverse the setting for the channel that feeds the ESC that is backing up. If no servo reversing is available, switch the power lead polarity on the motor that is backing up.
Given right turn command, robot turns left, and vice versa.
Swap the receiver plugs for the two channels that control the ESC -- if you are using channels 1 and 2, unplug the receiver connectors and replug the connector that was in channel 1 into channel 2 and vice versa. You may have to correct the servo reversing for the two channels after doing this, but the turning will be correct when you're done.
Robot control is like on/off switch. No low speed control.
Consult ESC manual for proper set-up of throttle end points. For servo-based drive, set Adjustable Travel Volume (ATV) control on transmitter (if available) to expand control of the limited response range of the ESC.
Robot has full range of control, but throttle is too 'touchy' at low speeds.
The Exponential Rate Response (EXP) available on many transmitters can reduce (or increase) the sensitivity of a control channel near the neutral control point. If you're using elevon mixing, dial in a negative value for EXP on channel 2.
Robot difficult to turn smoothly, enters 'spin' mode too easily.
If you're using elevon mixing, decreasing the channel 1 mix percentage will reduce the maximum spin rate of the robot and make it more stable in turns. You may also try setting a moderate negative value for EXP on channel 1 to reduce sensitivity near neutral but retain the high spin rate at full stick input.
An alternate solution is to set a Dual Rate (D/R) switch to restrict maximum turn rate for maneuvering, but still allow full spin rate for special attacks or a victory dance. Consult your transmitter manual for details.
Two-wheeled robot difficult to drive in straight line, or robot with more wheels difficult to carve smooth turns.
A solid-state gyro can help with either of these stability problems.
See Programming the Futaba 6XAPs for Combat Robotics for more detail on transmitter set-up.
