When a sparkplug does its thing in an engine cylinder, it creates a small cloud of ions in a gaseous mixture of fuel and air. This conducts electricity -a mini lightning bolt which then ignites the fuel and drives the piston.
There are lots of patents which are concerned with how the cloud of ions may be better dispersed using eg ultrasound or magnetic elements of the sparkplug.
Todays invention instead attempts this using a strong magnet embedded in the piston crown. As the piston moves through the top dead centre position, this drags the ions created into a column between the plug gap and piston crown -extending the initial spark front and providing a fuel burn which is better spread in an axial direction within the cylinder.
Using an electromagnet with electronically controlled flux density as a function of crank position may further enhance this effect and decrease ‘knocking.’