CVT target engine speed control for coasting and retarding

摘要

A machine may include an engine, a traction device, a continuously variable transmission (CVT) connecting the engine to the traction device, an operator input device outputting engine output command signals input by an operator, an engine speed sensor monitoring an engine output speed, and an electronic control module (ECM). The ECM may control the engine to a non-retarding target engine speed when a commanded engine output is greater than zero, a retarding target engine speed when the commanded engine output is zero and a commanded brake force is greater than zero, and a coasting target engine speed when the commanded engine output is zero and the commanded brake force is zero. The ECM may use engine speed sensor signals as feedback, and determine a CVT transmission ratio that will cause the CVT to apply a load to the engine that will cause the engine to run at the specified target engine speed.