Why in the movie Mrs Doubtfire did Daniel Hillard disguise himself as a nanny?

Daniel Hillard disguised himself as a nanny in the movie Mrs Doubtfire to spend more time with his children after he and his wife, Miranda Hillard, separated. As per the court's decision, Daniel was only allowed supervised visits with his children as the judge was concerned about his mental state and parenting abilities. Disguising himself as a nanny allowed him to be present in his children's lives and to rebuild their relationship with them during the period of separation.