Vehicle drive system

A vehicle drive system comprising:

• a first drive device configured to drive a first drive wheel, which is either a front wheel or a rear wheel of a vehicle;
• a second drive device configured to drive a second drive wheel, which is the other of the front wheel or the rear wheel of the vehicle;
• and
• a control device configured to control the first drive device and the second drive device, to controls a drive state of the first drive wheel and the second, drive wheel,
• wherein the control device comprises
• a slip acquisition unit configured to acquires that an excessive slip which is slipping of the first drive wheel or the second drive wheel by a predetermined amount or more, is occurring,
• an addition slip point calculating unit configured to calculate addition slip points in a time-discrete manner, based on the slip acquisition unit having acquired that the excessive slip has occurred,
• a cumulative slip point calculating unit configured to accumulate the addition slip points and calculate a cumulative slip point over time,
• a drive state switching unit configured to realize an in part-wheel drive state where the vehicle is driven by only one of the first drive wheel and the second drive wheel in a case where the cumulative slip point is smaller than a predetermined drive state switching threshold value, and to realize an all-wheel drive state where the vehicle is driven by both the first drive wheel and the second drive wheel in a case where the cumulative slip point is equal to or greater than the drive state switching threshold value, and
• a cumulative slip point resetting unit configured to reset the cumulative slip point to a value smaller than the drive state switching threshold value, in a state where the drive state of the vehicle has been switched to the all-wheel drive state by the drive state switching unit, and a drive force correlation value having correlation to drive force of the drive wheel reaches a predetermined drive force correlation threshold value or higher.

A vehicle drive system comprising:

• a first drive device configured to drive a first drive wheel, which is either a front wheel or a rear wheel of a vehicle;
• a second drive device configured to drive second drive wheel, which is the other of the front wheel or the rear wheel of the vehicle;
• and
• a control device configured to control the first drive device and the second drive device, to control a drive state of the first drive wheel and the second drive wheel,
• wherein the control device comprises
• a slip acquisition unit configured to that acquires that an excessive slip, which is slipping of the first drive wheel or the second drive wheel by a predetermined amount or more, is occurring,
• an addition slip point calculating unit configured to calculate addition slip points in a time-discrete manner, based on the slip acquisition unit having acquired that the excessive slip has occurred,
• a cumulative slip point calculating unit configured to accumulate the addition slip points and calculate a cumulative slip point over time,
• a drive state switching unit configured to realize an in part-wheel drive state where the vehicle is driven by only one of the first drive wheel and the second drive wheel in a case where the cumulative slip point is smaller than a predetermined drive state switching threshold value, and to realize an all-wheel drive state where the vehicle is driven by both the first drive wheel and the second drive wheel in a case where the cumulative slip point is equal to or greater than the drive state switching threshold value, and
• a cumulative slip point resetting unit configured to reset, the cumulative slip point to a value smaller than the drive state switching threshold value, in a state where the drive state of the vehicle has been switched to the all-wheel drive state by the drive state switching unit, and a lateral acceleration correlation value having correlation to lateral acceleration of the vehicle reaches a predetermined lateral acceleration threshold value or higher, or the drive force correlation value having correlation to drive force of the drive wheel reaches a drive force correlation threshold value or higher.