Powertrain control apparatus and method, and program for implementing the control method

A method for controlling a powertrain that includes an automatic transmission that forms one gear by engaging a one-way clutch and forms another gear than the one gear by engaging a predetermined frictional engagement element, the control method comprising:

• detecting whether slip is occurring in the one-way clutch when the one gear is formed, wherein it is determined that slip is occurring when a first rotation member and a second rotation member of the one-way clutch rotate relative to each other;
• determining whether an engagement condition for engaging the predetermined frictional engagement element is satisfied when slip is detected in the one way clutch, wherein the engagement condition is satisfied when a rotational speed difference between the first rotation member and the second rotation member increases;
• and
• executing an engagement control to engage the predetermined frictional engagement element if the engagement condition is satisfied when slip is detected in the one way clutch.

A control apparatus for a powertrain that includes an automatic transmission that forms one gear by engaging a one-way clutch and forms another gear than the one gear by engaging a predetermined frictional engagement element, the control apparatus comprising:

• means for detecting the occurrence of slip in the one-way clutch when the one gear is formed, wherein it is determined that slip occurs when a first rotation member and a second rotation member of the one-way clutch rotate relatively;
• means for determining whether an engagement condition for engaging the predetermined frictional engagement element is satisfied when slip is detected in the one-way clutch, wherein the engagement condition is satisfied when the rotational speed difference between the first rotation member and the second rotation member increases;
• and
• means for executing a control to engage the predetermined frictional engagement element if the condition is satisfied when slip is detected in the one-way clutch.