1979: Canada Voters Lists at Empress, Alberta, Canada.
Right after his name is: Robinson, O'Linda, (F), who I presume was his wife.
That is the only piece of information I have found that is definitely for this person.
Some people on Ancestry have a "Charles Pettet Robinson", who was born 1913 and died 2002-Oct-04, and someone once mistakenly connected him with this grave in the Empress Cemetery. That death date does not match this headstone, 1983 on this headstone vs. 2002 for records of this other man. That "Charles Pettet Robinson" is in the 1916 & 1921 Canada Census with his family in central Alberta (near Ferintosh), then the 1931 Census in Calgary with his mother & siblings. In 1933 he married "Phyllis M. Ethredge" at Strathmore, Alberta.
If the two are the same man, then those people have his death date wrong. It will not be until the year 2033 that Alberta will release the Death Register information for the year 1983, and the truth can be discovered.