Engine valve actuation with handoff control between cooperative valve actuation motions

A valve actuation system for actuating at least one engine valve, the valve actuation system comprising:

• a first motion transfer mechanism operatively connected to a first valve actuation motion source and to the at least one engine valve;
• a second motion transfer mechanism operatively connected to a second valve actuation motion source;
• and
• a selectable coupling mechanism disposed between the first motion transfer mechanism and the second motion transfer mechanism,
• wherein, when the selectable coupling mechanism is operated in a first state, first valve actuation motions provided by the first valve actuation motion source are conveyed to the at least one engine valve via the first motion transfer mechanism and, when the selectable coupling mechanism is operated in a second state, in addition to the first valve actuation motions conveyed via the first motion transfer mechanism, second valve actuation motions provided by the second valve actuation motion source are conveyed to the at least one engine valve via the second motion transfer mechanism, the coupling mechanism and the first motion transfer mechanism,
• and wherein, during a handoff between the first valve actuation motions and the second valve actuation motions or vice versa, a difference in valve actuation velocities of the first valve actuation motions and the second valve actuation motions does not exceed a threshold.