Gregory Benford – Galactic Center

2019: NASA astronaut Nigel Walmsley is sent on a mission to intercept a rogue asteroid on a collision course with Earth. Ordered to destroy the comet, he instead discovers that it is actually the shell of a derelict space probe - a wreck with just enough power to emit a single electronic signal...
2034: Then a reply is heard. Searching for the source of this signal that comes from outside the solar system, Nigel discovers the existence of a sentient ship. When the new vessel begins to communicate directly with him, the astronaut learns of the horrors that await humanity. For the ship was created by an alien race that has spent billions and billions of years searching for intelligent life...to annihilate it.

2076: Lancer, Earth's first starship, is on a mission to find interstellar civilizations. Although astronaut Nigel Walmsley's experiences with alien encounters make him the expert, no one believes Nigel's theory that machines are the dominant intelligent beings left in the galaxy and that their purpose is to annihilate all organic life.
Then the explorers discover once-living planets where only machines remain - and ruined worlds where fugitive survivors must evade omnipresent and lethally advanced A.I. warships. By the time the crew of Lancer realizes that Nigel is right, it will be too late - for the machines have already found Lancer... and Earth.

Nearly 100,000 years after first contact with the machines that dominate the universe, only a few hundred humans survive. Trapped on Snowglade, a barren world near the center of the galaxy, Killeen and his child Toby of the Bishop Tribe are primitive scavengers, homeless and hunted by the ruling mechs. Then suddenly, a strange cosmic entity - neither organic nor cybernetic nor living matter - reaches out from a black hole to speak with Killeen. But can the fallen descendant of starfarers understand this alien being in time- and seize his only chance to save his family and mankind from final annihilation?

Onboard an ancient starship, Killeen and the Bishop tribe escape the mech-ruled world of Snowglade. Seeking refuge on a faraway planet, they discover vast wonders- an organic life-form as large as a world, a planet-coring cosmic string, a community of humans ruled by a brutal tyrant, and ultimately an alien race more awesome thaan any they have encountered. As they battle for survival against these myriad dangers, Killeen and his crew will gain an unforeseen ally- one that may determine humanity's true destiny...

Trying to escape the relentless mechs, the last humans from the planet Snowglade take their ancient starship on a dangerous course straight into the Eater, the black hole at the galactic center. Hungry and desperate, the refugees begin to question the leadership of Captain Killeen, who believes the center holds their one hope of survival. Meanwhile, Killeen's son Toby struggles with the microchips that were implanted in his spine- a technology that now threatens his sanity. Caught between their genocidal pursuers and peril in the galactic center, Killeen and Toby bring huanity to its final destiny.

Millennia of conflict between humans and mechs have driven the human race to near-extinction. Now as the fierce AI mechs begin their final assault on mankind, it soon becomes apparent that three men- three generations in a family of voyagers- are their targets. Toby Bishop, his father, Killeen Bishop, and his grandfather, Nigel Walmsley, each carry a piece of the lethal secret that can destroy their enemies. But hunted through space and time by relentless assassins, they have no idea that they possess the only weapon that can save humanity...